Document and Entity Information [Abstract] Document and Entity Information [Abstract] Statement [Table] Statement [Line Items] Document Type Amendment Flag Document Period End Date Document Fiscal Period Focus Document Fiscal Year Focus Entity Registrant Name Trading Symbol Entity Central Index Key Current Fiscal Year End Date Entity Filer Category Entity Common Stock, Shares Outstanding Entity Current Reporting Status Entity Public Float Entity Voluntary Filers Entity Well-known Seasoned Issuer Consolidated Balance Sheets [Abstract] Assets [Abstract] Assets Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents at end of year Cash and cash equivalents at beginning of year Cash and cash equivalents Available-for-sale Securities, Current Marketable securities Amount of investments in level 1 mutual funds related to a non-qualified supplemental executive retirement plan and a non-qualified pharmacist deferred compensation plan for certain of its associates. SERP Investment SERP investment Accounts Receivable, Net, Current Accounts receivable, net Inventory, Net Inventories Inventories Prepaid Expense, Current Prepaid expenses and other current assets Income Taxes Receivable, Current Income taxes recoverable Assets, Current Total current assets Property, Plant and Equipment, Net Property and equipment, net Property and equipment, net Goodwill Goodwill Sum of the carrying amounts of all intangible assets and other assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges. Intangible Assets Assets and Other Assets, Net (Excluding Goodwill) Intangible and other assets, net Assets Total assets Liabilities and Stockholders' Equity [Abstract] Liabilities [Abstract] Liabilities Accounts Payable, Current Accounts payable Accrued Liabilities, Current Accrued expenses Self Insurance Reserve, Current Accrued self-insurance Deferred Revenue, Current Deferred revenue, net Liabilities, Current Total current liabilities This represents the noncurrent liability recognized in the balance sheet that is associated with the Company's postretirement defined benefit plan, the Deferred Compensation Plan, as well as noncurrent liabilities related to the non-qualified supplemental executive retirement plan (SERP) and the non-qualified pharmacist deferred compensation plan as of the balance sheet date. Both the SERP and the pharmacist deferred compensation plan are designed to provide retirement benefits and salary deferral opportunities because of limitations imposed by the Internal Revenue Code and the Regulations implemented by the Internal Revenue Service. All three plans are unfunded and accounted for on an accrual basis. Postretirement benefit obligations Self Insurance Reserve, Noncurrent Accrued self-insurance Deferred Tax Liabilities, Noncurrent Deferred income taxes Long-term Debt, Excluding Current Maturities Long-term debt Other Liabilities, Noncurrent Other Liabilities Total liabilities Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Shareholders' Equity Common Stock, Value, Issued Common stock, no par value, 100,800,000 shares authorized, 33,047,807 shares issued, 26,898,443 shares outstanding Retained Earnings (Accumulated Deficit) Retained earnings Accumulated Other Comprehensive Income (Net of deferred taxes of $3,782 in 2016 and $3,323 in 2015) Accumulated other comprehensive income, net Stockholders' Equity before Treasury Stock Shareholders' equity before treasury stock Treasury Stock, Value Treasury stock at cost, 6,149,364 shares Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Balance, Balance, Total shareholders' equity Liabilities and Stockholders' Equity Total liabilities and shareholders' equity Common Stock, No Par Value Common stock, par value Common Stock, Shares Authorized Common stock, shares authorized Common Stock, Shares, Issued Common stock, shares issued Common Stock, Shares, Outstanding Common stock, shares outstanding Treasury Stock, Shares Treasury stock, shares Consolidated Statements of Income [Abstract] Sales Revenue, Goods, Net Net sales Cost of sales consists of direct product costs (net of discounts and allowances), warehouse costs, transportation costs and manufacturing facility costs. Also included are vendor allowances recorded as credits in cost of sales. Cost of sales, including warehousing and distribution expenses Gross Profit Gross profit on sales Gross profit on sales Selling, General and Administrative Expense Operating, general and administrative expenses Operating Income (Loss) Income from operations Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities plus amount of the cost of borrowed funds accounted for as interest expense. Investment income (loss) and interest expense Investment income and interest expense Business Combination, Bargain Purchase, Gain Recognized, Amount Gain on acquisition of business Gain on bargain purchase Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Cumulative Effects of Changes in Accounting Principles, Noncontrolling Interest Income before provision for income taxes Income Tax Expense (Benefit) Provision for income taxes Provision for income taxes Provision for income taxes Net Income (Loss) Attributable to Parent Net income Net income Weighted-average shares outstanding, basic and diluted Common Stock, Dividends, Per Share, Declared Cash dividends per share Earnings Per Share, Basic and Diluted Basic and diluted earnings per share Consolidated Statements of Comprehensive Income [Abstract] Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax [Abstract] Other comprehensive income (loss) by component, net of tax: Unrealized holding gains arising during period, tax Available-for-sale marketable securities Unrealized holding gains (losses) arising during period (Net of deferred taxes of $239, $37 and $644, respectively) Reclassification adjustment for gains included in net income (net of deferred taxes) Reclassification adjustment for gains included in net income (Net of deferred taxes of $180, $11 and $26, respectively) Other Comprehensive Income (Loss), Available for Sale Securities Adjustment, Net of Tax Other comprehensive income (loss), net of reclassification adjustments and tax Other comprehensive income (loss), net of tax Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive income, net of tax Other Comprehensive Income (Loss), Available-for-sale Securities, Tax, Portion Attributable to Parent Unrealized holding gains (losses) arising during period, deferred taxes Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Tax Reclassification adjustment for gains included in net income, deferred taxes Statement of Stockholders' Equity [Abstract] Shares, Outstanding Balance, shares Balance, shares Dividends Dividends paid Consolidated Statements of Cash Flows [Abstract] Cash and Cash Equivalents, Period Increase (Decrease) [Abstract] Net Cash Provided by (Used in) Operating Activities [Abstract] Cash flows from operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Depreciation Amortization of Intangible Assets Amortization Gain (Loss) on Sale of Property Plant Equipment Loss (gain) on disposition of fixed assets Impairment of Long-Lived Assets Held-for-use Impairment of fixed assets Gain (Loss) on Sale of Investments Gain on sale of marketable securities Gain (Loss) on Disposition of Intangible Assets Gain on sale of intangible assets Deferred Income Tax Expense (Benefit) Deferred income taxes Increase (Decrease) in Operating Capital [Abstract] Changes in operating assets and liabilities: Increase (Decrease) in Inventories Inventories The net change during the reporting period of the sum of amounts due within one year (or one business cycle) from customers for the credit sale of goods and services. Also includes the net change during the reporting period in the amount of outstanding money paid in advance for goods or services that bring economic benefits for future periods. Increase (Decrease) in Accounts Receivable and Prepaid Expenses Accounts receivable and prepaid expenses Increase (Decrease) in Income Taxes Receivable Income taxes recoverable Increase (Decrease) in Accounts Payable and Accrued Liabilities Accounts payable and other liabilities Increase (Decrease) in Accrued Income Taxes Payable Income taxes payable Increase (Decrease) in Other Operating Assets and Liabilities, Net Other Net Cash Provided by (Used in) Operating Activities, Continuing Operations Net cash provided by operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash flows from investing activities: Payments to Acquire Property, Plant, and Equipment Purchase of property and equipment Proceeds from Sale of Property, Plant, and Equipment Proceeds from the sale of property and equipment Payments to Acquire Available-for-sale Securities Purchase of marketable securities Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities Proceeds from maturities of marketable securities Proceeds from Sale of Held-to-maturity Securities Proceeds from the sale of marketable securities Payments to Acquire Businesses, Net of Cash Acquired Acquisition of business Purchase price Payments to Acquire Intangible Assets Purchase of intangible assets Proceeds from Sale of Intangible Assets Proceeds from sale of intangible assets The net cash inflow (outflow) during the period for investments in level 1 mutual funds related to a non-qualified supplemental executive retirement plan and a non-qualified pharmacist deferred compensation plan for certain of its associates. Change in SERP investment Net Cash Provided by (Used in) Investing Activities, Continuing Operations Net cash used in investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from financing activities: Proceeds from Issuance of Long-term Debt Proceeds from long-term debt Payments of Dividends, Common Stock Dividends paid Net Cash Provided by (Used in) Financing Activities, Continuing Operations Net cash provided by (used in) financing activities Cash and Cash Equivalents, Period Increase (Decrease) Net (decrease) increase in cash and cash equivalents Summary of Significant Accounting Policies [Abstract] Significant Accounting Policies [Text Block] Significant Accounting Policies Marketable Securities [Abstract] Marketable Securities [Text Block] Marketable Securities Inventories [Abstract] Inventories Text Inventories Property and Equipment [Abstract] Property, Plant and Equipment Disclosure [Text Block] Property and Equipment Lease Commitments [Abstract] Leases of Lessee Disclosure [Text Block] Lease Commitments Retirement Plans [Abstract] Pension and Other Postretirement Benefits Disclosure [Text Block] Retirement Plans Accumulated Other Comprehensive Income [Abstract] Stockholders' Equity Note Disclosure [Text Block] Accumulated Other Comprehensive Income Income Taxes [Abstract] Income Tax Disclosure [Text Block] Income Taxes Acquisition of Business [Abstract] Business Combination Disclosure [Text Block] Acquisition of Business Summary of Quarterly Results [Abstract] Quarterly Financial Information [Text Block] Summary of Quarterly Results Fair Value Information [Abstract] Fair Value Disclosures [Text Block] Fair Value Information Commitments and Contingencies [Abstract] Commitments and Contingencies Disclosure [Text Block] Commitments and Contingencies Long-Term Debt [Abstract] Debt Disclosure [Text Block] Long-Term Debt Valuation and Qualifying Accounts [Abstract] Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] Disclosure of the company's background and nature of operations. Description of Business [Policy Text Block] Fiscal Period, Policy [Policy Text Block] Definition of Fiscal Year [Policy Text Block] Consolidation, Policy [Policy Text Block] Principles of Consolidation [Policy Text Block] Use of Estimates, Policy [Policy Text Block] Use of Estimates [Policy Text Block] Cash and Cash Equivalents, Policy [Policy Text Block] Cash and Cash Equivalents [Policy Text Block] Marketable Securities, Policy [Policy Text Block] Marketable Securities [Policy Text Block] Trade and Other Accounts Receivable, Policy [Policy Text Block] Accounts Receivable [Policy Text Block] Inventory, Policy [Policy Text Block] Inventories [Policy Text Block] Property, Plant and Equipment, Policy [Policy Text Block] Property and Equipment [Policy Text Block] Goodwill and Intangible Assets, Policy [Policy Text Block] Goodwill and Intangible Assets [Policy Text Block] Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Impairment of Long-Lived Assets [Policy Text Block] Costs Associated with Exit or Disposal Activities or Restructurings, Policy, Ongoing Benefit Arrangements [Policy Text Block] Store Closing Costs [Policy Text Block] Disclosure of the Company's self insurance policy for workers' compensation, general liability, vehicle accident and associate medical benefit claims. Self Insurance Policy [Policy Text Block] Self-Insurance [Policy Text Block] Income Tax, Policy [Policy Text Block] Income Taxes [Policy Text Block] Earnings Per Share, Policy [Policy Text Block] Earnings Per Share [Policy Text Block] Revenue Recognition, Policy [Policy Text Block] Revenue Recognition [Policy Text Block] Cost of Sales, Policy [Policy Text Block] Cost of Sales, Including Warehousing and Distribution Expenses [Policy Text Block] Cost of Sales, Vendor Allowances, Policy [Policy Text Block] Vendor Allowances [Policy Text Block] Selling, General and Administrative Expenses, Policy [Policy Text Block] Operating, General and Administrative Expenses [Policy Text Block] Advertising Costs, Policy [Policy Text Block] Advertising Costs [Policy Text Block] Revenue Recognition Leases, Operating [Policy Text Block] Rental Income [Policy Text Block] New Accounting Pronouncements, Policy [Policy Text Block] Tabular disclosure of assets, excluding financial assets and goodwill, lacking physical substance with a finite or indefinite life, by either major class or business segment. Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Table Text Block] Restructuring and Related Costs [Table Text Block] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities Reconciliation [Table Text Block] Marketable securities [Table Text Block] Investments Classified by Contractual Maturity Date [Table Text Block] Maturities of marketable securities classified as available-for-sale [Table Text Block] Schedule of Inventory, Current [Table Text Block] Merchandise Inventories [Table Text Block] Property, Plant and Equipment [Table] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Table Text Block] Schedule of Operating Leased Assets [Table] Operating Leased Assets [Line Items] Schedule of Rent Expense [Table Text Block] Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plan Disclosure [Line Items] Schedule of Costs of Retirement Plans [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Line Items] Acquisitions [Line Items] Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Business Acquisition, Pro Forma Information [Table Text Block] Quarterly Financial Information [Table Text Block] Range [Axis] Range [Member] Range [Domain] Maximum [Member] Maximum [Member] Minimum [Member] Minimum [Member] Statement, Scenario [Axis] Scenario Unspecified [Domain] Scenario, Unspecified [Domain] Between March 1, 2013 to March 1, 2014 [Member] Between March12013 To March12014 [Member] Between March 1, 2013 to March 1, 2014 [Member] Fiscal Period Duration Cash Equivalents, at Carrying Value Allowance for Doubtful Accounts Receivable Self Insurance, Annual Maximum of Health Claims Liability per Associate Self Insurance, Annual Maximum of Health Claims Liability per Associate Self Insurance, Maximum of Workers Compensation Claims Liability per Associate per Claim Self Insurance, Maximum of Workers Compensation Claims Liability per Associate per Claim Stop loss insurance specific deductible. Stop loss insurance specific deductible Stop loss insurance aggregating deductible. Stop loss insurance aggregating deductible Property and Casualty Insurance, Deductible Property and Casualty Insurance, Deductible Vendor Allowances recorded as credits in Cost of Goods Sold Cost of Goods Sold, Vendor Allowances Vendor Paid Cooperative Advertising Credits Vendor Paid Cooperative Advertising Credits Accounts Receivable, Earned Advertising Credits Accounts Receivable, Earned Advertising Credits Accounts Receivable, Earned Promotional Discounts Accounts Receivable, Earned Promotional Discounts Unearned income included in accrued liabilities for unearned vendor programs under long-term contracts for display and shelf space allocation. Unearned Income for Vendor Programs Advertising Expense Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Table] Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Table] Finite-Lived and Indefinite-Lived Intangible Assets [Line Items] Finite-Lived and Indefinite-Lived Intangible Assets [Line Items] Indefinite-Lived Intangible Assets (Excluding Goodwill) Finite-Lived Intangible Assets, Gross Finite-Lived Intangible Assets, Gross Finite-Lived Intangible Assets, Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Finite-Lived Intangible Assets, Net Finite-Lived Intangible Assets, Net Intangible Assets, Gross (Excluding Goodwill) Intangible Assets, Net (Excluding Goodwill) Finite-Lived Intangible Asset, Useful Life Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months Finite-Lived Intangible Assets, Amortization Expense, Year Two Finite-Lived Intangible Assets, Amortization Expense, Year Three Finite-Lived Intangible Assets, Amortization Expense, Year Four Finite-Lived Intangible Assets, Amortization Expense, Year Five Schedule of Restructuring and Related Costs [Table] Restructuring Cost and Reserve [Line Items] Lessee Leasing Arrangements, Operating Leases, Term of Contract Remaining lease term of closed stores Restructuring Reserve Closed store lease liabilities, Ending Balance Closed store lease liabilities, Beginning Balance Restructuring Costs Additions Payments for Restructuring Payments Restructuring Reserve, Accrual Adjustment Adjustments Available-for-sale Securities, Amortized Cost Basis Available-for-sale Securities, Amortized Cost, Total Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Holding Gains Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Gross Unrealized Holding Losses Available-for-sale Securities Fair Value Available-for-sale Securities, Fair Value, Total Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost Basis Amortized Cost, Due within one year Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value Fair Value, Due within one year Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost Basis Amortized Cost, Due after one year through five years Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value Fair Value, Due after one year through five years Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost Basis Amortized Cost, Due after five years through ten years Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value Fair Value, Due after five years through ten years Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Amortized Cost Basis Amortized Cost, Due after ten years Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value Fair Value, Due after ten years Available-for-sale Equity Securities, Amortized Cost Basis Amortized Cost, Equity securities Available-for-sale Securities, Equity Securities Fair Value, Equity securities Inventory, Current [Table] Inventory [Line Items] LIFO Average Cost Excess of Replacement or Current Costs over Stated LIFO Value Property, Plant and Equipment, Gross Property and equipment, at cost Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Less accumulated depreciation and amortization Property and equipment, useful life Percentage of open store facilities leased through operating leasing arrangements. Percentage of facilities under operating lease Lease Expiration Date Lessee Leasing Arrangements, Operating Leases, Renewal Term Accrued Rent Operating Leases, Rent Expense, Minimum Rentals Minimum annual rentals Operating Leases, Rent Expense, Contingent Rentals Contingent rentals Operating Leases, Rent Expense, Sublease Rentals Lease or sublease income Operating Leases, Rent Expense, Net Operating Leases, Rent Expense, Net, Total Operating Leases, Future Minimum Payments Due, Next Twelve Months Operating Leases, Future Minimum Payments, Due in Two Years Operating Leases, Future Minimum Payments, Due in Three Years Operating Leases, Future Minimum Payments, Due in Four Years Operating Leases, Future Minimum Payments, Due in Five Years Operating Leases, Future Minimum Payments, Due Thereafter Operating Leases, Future Minimum Payments Due Operating Leases, Future Minimum Payments Due, Total Operating Leases, Future Minimum Payments Receivable, Current Operating Leases, Future Minimum Payments Receivable, Current Operating Leases, Future Minimum Payments Receivable, in Two Years Operating Leases, Future Minimum Payments Receivable, in Two Years Operating Leases, Future Minimum Payments Receivable, in Three Years Operating Leases, Future Minimum Payments Receivable, in Three Years Operating Leases, Future Minimum Payments Receivable, in Four Years Operating Leases, Future Minimum Payments Receivable, in Four Years Operating Leases, Future Minimum Payments Receivable, in Five Years Operating Leases, Future Minimum Payments Receivable, in Five Years Operating Leases, Future Minimum Payments Receivable, Thereafter Operating Leases, Future Minimum Payments Receivable, Thereafter Operating Leases, Future Minimum Payments Receivable Operating Leases, Future Minimum Payments Receivable, Total Number of supplemental retirement plans covering highly compensated employees. Number of supplemental retirement plans Defined Benefit Plan, Benefit Obligation This represents the present value of the accumulated benefits of the Company's non-qualified supplemental executive retirement plan (SERP) and the non-qualified deferred compensation plan for pharmacists , which are recognized in the balance sheet as a noncurrent liability. Both the SERP and the deferred compensation plan for pharmacists are designed to provide retirement benefits and salary deferral opportunities because of limitations imposed by the Internal Revenue Code and the Regulations implemented by the Internal Revenue Service. The plans are unfunded and accounted for on an accrual basis. Retirement Plans, Accumulated Benefit Obligation Deferred Compensation Arrangement with Individual, Requisite Service Period Pension Expense Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months 2017 Amount of benefits from a defined benefit plan expected to be paid consistently per year once stabalized. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. DefinedBenefitPlanExpectedConstantPayments Thereafter Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive income balance, ending balance Accumulated other comprehensive income balance, beginning balance Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Other comprehensive income (loss) before reclassifications Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Amounts reclassified from accumulated other comprehensive income Other Comprehensive Income (Loss), Net of Tax Other comprehensive income (loss), net of tax Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Income Taxes Paid Income Tax Examination, Year under Examination Internal Revenue Service income tax examination, year Open Tax Year Operating Loss Carryforwards Operating Loss Carryforwards, Expiration Date Current Federal Tax Expense (Benefit) Current Federal Income Tax Expense (Benefit) Current State Tax Expense (Benefit) Current State Income Tax Expense (Benefit) Deferred Federal Income Tax Expense (Benefit) Deferred State Income Tax Expense (Benefit) Income Tax Reconciliation, Income Tax Expense (Benefit), at Federal Statutory Income Tax Rate Income taxes at federal statutory rate Income Tax Reconciliation, State and Local Income Taxes State income taxes, net of federal income tax benefit Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deferred tax gain on bargain purchase. Effective Income Tax Reconciliation, Deferred Tax Gain on Bargain Purchase Deferred tax on gain on bargain purchase Income Tax Reconciliation, Other Adjustments Other Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Effective Income Tax Rate Reconciliation, Percent Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Allowance for Doubtful Accounts Accounts receivable Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Compensated Absences Compensated absences Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Other Employment incentives Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits Employee benefit plans Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities General liability insurance Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Postretirement Benefits Postretirement benefit obligations Deferred Tax Assets, Operating Loss Carryforwards Net operating loss carryforwards Deferred Tax Assets, Tax Deferred Expense, Other Other Deferred Tax Assets, Gross Total deferred tax assets Deferred Tax Liabilities, Inventory Inventories Deferred Tax Liabilities, Other Comprehensive Income Unrealized gains on marketable securities Deferred Tax Liabilities, Deferred Expense, Reserves and Accruals Nondeductible accruals and other Deferred Tax Liabilities, Property, Plant and Equipment Depreciation Deferred Tax Liabilities, Gross Total deferred tax liabilities Deferred Tax Liabilities, Net Net deferred tax liability Income Tax Contingency [Table] Income Tax Contingency [Line Items] Unrecognized Tax Benefits Unrecognized tax benefits at end of year Unrecognized tax benefits at beginning of year Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions Increases based on tax positions related to the current year Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions Additions for tax positions of prior year Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions Reductions for tax positions of prior years Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities Settlements Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations Expiration of the statute of limitations for assessment of taxes Unrecognized tax benefits that would impact effective tax rate Business Acquisition [Axis] Business Acquisition Acquiree [Domain] Business Acquisition, Acquiree [Domain] Mars Super Market [Member] Mars Super Market [Member] Mars Super Market [Member] Food Lion, LLC [Member] Food Lion Llc [Member] Food Lion, LLC [Member] Nell's Family Market [Member] Nell S Family Market [Member] Nell's Family Market [Member] C&S Wholesale Grocers [Member] C S Wholesale Grocers [Member] C&S Wholesale Grocers [Member] Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual Sales Number of stores acquired. Number of stores acquired Number of owned stores acquired. Number of owned stores acquired Business Combination, Consideration Transferred, Liabilities Incurred Purchase price payable Debt Instrument, Term Purchase price payable, term The number of lease obligations assumed as part of an acquisition. Number of lease obligations assumed Number of new lease agreements entered into due to a business acquisition. Number of new lease agreements due to acquisition Business Acquisition, Goodwill, Expected Tax Deductible Amount Goodwill deductible for tax purposes Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Land Land Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Buildings Buildings Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Equipment Equipment Business Acquisition, Purchase Price Allocation, Current Assets, Inventory Inventories Amount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer, acquired at the acquisition date in addition to the amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer, acquired at the acquisition date. BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivablesandPrepaidExpenses Accounts receivable and prepaid expenses Business Acquisition, Purchase Price Allocation, Equipment Property and equipment, net Property and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Intangibles - favorable leasehold interest Intangibles - favorable leasehold interest, net Business Acquisition, Purchase Price Allocation, Assets Acquired Total fair value of assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Accounts receivable, net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets Prepaid expenses and other current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets Total current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable Accrued expenses Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities Total current liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other Other - unfavorable leasehold interest Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent Deferred tax liability Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Total liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Total fair value of assets acquired and liabilities assumed Business Acquisition, Purchase Price Allocation, Intangible Assets Other than Goodwill Intangible and other assets, net Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Total fair value of assets acquired and liabilties assumed Business Acquisition, Pro Forma Revenue Sales Line of Credit Facility [Table] Line of Credit Facility [Line Items] Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Fair Value of Amount Outstanding Debt Instrument, Maturity Date Debt Instrument, Basis Spread on Variable Rate Debt Instrument, Covenant, Minimum Earnings Before Interest, Tax, Depreciation and Amortization. Debt Instrument, Covenant, Minimum EBITDA Letters of Credit Outstanding, Amount Debt Instrument, Covenant Description Interest Expense, Debt Valuation and Qualifying Accounts Disclosure [Table] Valuation Allowances and Reserves Type [Axis] Valuation Allowances And Reserves [Domain] Valuation Allowances And Reserves [Domain] Allowance For Doubtful Accounts [Member] Allowance For Uncollectible Accounts [Member] Valuation and Qualifying Accounts Disclosure [Line Items] Valuation Allowances and Reserves, Balance Balance at End of Period Balance at Beginning of Period Valuation Allowances and Reserves, Additions for Charges to Cost and Expense Charged to Costs and Expenses Valuation Allowances and Reserves, Deductions Deductions Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock [Member] Common Stock [Member] Retained Earnings [Member] Retained Earnings [Member] Accumulated Other Comprehensive Income [Member] Accumulated Other Comprehensive Income (Loss) Attributable to Parent [Member] Treasury Stock [Member] Treasury Stock [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite Lived Intangible Assets Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Leases Acquired In Place [Member] Lease Acquisitions [Member] Customer Lists [Member] Customer Lists [Member] Indefinite-lived Intangible Assets [Axis] Indefinite Lived Intangible Assets Major Class Name [Domain] Indefinite-lived Intangible Assets, Major Class Name [Domain] Liquor Licenses [Member] Liquor Licenses [Member] Liquor Licenses [Member] Restructuring Type [Axis] Type Of Restructuring [Domain] Type of Restructuring [Domain] Facility Closing [Member] Facility Closing [Member] Major Types of Debt and Equity Securities [Axis] Major Types Of Debt And Equity Securities [Domain] Major Types of Debt and Equity Securities [Domain] Equity Securities [Member] Equity Securities [Member] Municipal Bonds [Member] Municipal Bonds [Member] Fair Value, Hierarchy [Axis] Fair Value Measurements Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Fair Value Inputs Level1 [Member] Fair Value, Inputs, Level 1 [Member] Fair Value Inputs Level2 [Member] Fair Value, Inputs, Level 2 [Member] Property, Plant and Equipment, Type [Axis] Property Plant And Equipment Type [Domain] Property, Plant and Equipment, Type [Domain] Land [Member] Land [Member] Building And Building Improvements [Member] Buildings and improvements [Member] Equipment [Member] Equipment [Member] Leasehold Improvements [Member] Leasehold improvements [Member] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plans [Domain] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Retirement savings plan [Member] Retirement Savings Plan [Member] Retirement savings plan [Member] Deferred compensation plan [Member] Deferred Compensation Plan [Member] Deferred compensation plan [Member] Supplemental Executive Retirement Plan [Member] Supplemental Executive Retirement Plan [Member] Supplemental executive retirement plan [Member] Deferred compensation plan for pharmacists [Member] Deferred Compensation Plan For Pharmacists [Member] Deferred compensation plan for pharmacists [Member] Accumulated Net Unrealized Investment Gain Loss [Member] Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification Out Of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification Out Of Accumulated Other Comprehensive Income [Member] Reclassification out of Accumulated Other Comprehensive Income [Member] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] Domestic Country [Member] Federal [Member] State And Local Jurisdiction [Member] State [Member] Information related to the Commonwealth of Pennsylvania. Pennsylvania [Member] Pennsylvania [Member] Tax Period [Axis] Tax Period [Domain] Tax Period [Domain] Earliest Tax Year [Member] Earliest Tax Year [Member] Latest Tax Year [Member] Latest Tax Year [Member] Geographical [Axis] Segment Geographical [Domain] Geographical [Domain] M [D] MARYLAND V [A] VIRGINIA D [E] DELAWARE Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility [Member] Revolving Credit Facility [Member] Line Of Credit [Member] Line of Credit [Member] Lender Name [Axis] Line Of Credit Facility Lender [Domain] Line of Credit Facility, Lender [Domain] Wells Fargo Bank, N.A. [Member] Wells Fargo Bank N.a. [Member] Wells Fargo Bank, N.A. [Member] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] London Interbank Offered Rate L I B O R [Member] London Interbank Offered Rate (LIBOR) [Member] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member]