Annual report pursuant to Section 13 and 15(d)

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)

v2.4.1.9
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)
 0 Months Ended 12 Months Ended
May 29, 2012
Jan. 31, 2015
Feb. 01, 2014
Feb. 02, 2013
Property, Plant and Equipment [Line Items]        
Fixed price of merchandise   $ 1.00dltr_SalesPricePerItemRangeMaximum    
Discount variety retail stores owned and operated   5,367dltr_StoresOwnedAndOperated    
Common stock dividend (in hundredths) 100.00%dltr_DividendsCommonStockStockPercentage      
Stock split conversion ratio 2us-gaap_StockholdersEquityNoteStockSplitConversionRatio1      
Money market securities valued at cost, in Cash and cash equivalents   788,600,000us-gaap_MoneyMarketFundsAtCarryingValue 172,600,000us-gaap_MoneyMarketFundsAtCarryingValue  
Debt instruments with original maturities in months, considered cash equivalents, range maximum (in months)   3 months    
Settlement of debit card and credit card transaction process business days, range maximum (in business days)   3 days    
Warehousing and distribution costs capitalized into inventory   44,300,000us-gaap_RetailRelatedInventoryPackagingAndOtherSupplies 43,200,000us-gaap_RetailRelatedInventoryPackagingAndOtherSupplies  
Software amortization period (in years)   3 years    
Deferred Finance Costs, Noncurrent, Net   74,300,000us-gaap_DeferredFinanceCostsNoncurrentNet 4,300,000us-gaap_DeferredFinanceCostsNoncurrentNet  
Deferred Finance Costs, Current, Gross   70,200,000us-gaap_DeferredFinanceCostsCurrentGross    
Accrued deferred financing costs   58,400,000dltr_Accrueddeferredfinancingcosts 0dltr_Accrueddeferredfinancingcosts  
Restricted investments   78,900,000us-gaap_RestrictedInvestmentsNoncurrent 87,900,000us-gaap_RestrictedInvestmentsNoncurrent  
Deferred Compensation Plan Assets   5,500,000us-gaap_DeferredCompensationPlanAssets 5,100,000us-gaap_DeferredCompensationPlanAssets  
Impairment charge for certain store assets   1,500,000us-gaap_ImpairmentOfLongLivedAssetsHeldForUse 500,000us-gaap_ImpairmentOfLongLivedAssetsHeldForUse 500,000us-gaap_ImpairmentOfLongLivedAssetsHeldForUse
Cash and cash equivalents fair value   864,100,000us-gaap_CashAndCashEquivalentsFairValueDisclosure 267,700,000us-gaap_CashAndCashEquivalentsFairValueDisclosure  
Restricted investments fair value   78,900,000dltr_RestrictedInvestmentsFairValue 87,900,000dltr_RestrictedInvestmentsFairValue  
Fair value of diesel fuel swap   5,700,000dltr_DerivativeFinancialInstrumentsLiabilitiiesFairValueDieselFuelSwapDisclosure    
Long-term Debt, Fair Value   700,900,000us-gaap_LongTermDebtFairValue 769,800,000us-gaap_LongTermDebtFairValue  
Advertising costs   18,100,000us-gaap_AdvertisingExpense 14,900,000us-gaap_AdvertisingExpense 13,500,000us-gaap_AdvertisingExpense
Stock-based compensation expense   $ 37,400,000us-gaap_AllocatedShareBasedCompensationExpense $ 36,200,000us-gaap_AllocatedShareBasedCompensationExpense $ 34,900,000us-gaap_AllocatedShareBasedCompensationExpense
Buildings [Member] | Minimum [Member]        
Property, Plant and Equipment [Line Items]        
Useful life (in years)   39 years    
Buildings [Member] | Maximum [Member]        
Property, Plant and Equipment [Line Items]        
Useful life (in years)   40 years    
Furniture, fixtures and equipment [Member] | Minimum [Member]        
Property, Plant and Equipment [Line Items]        
Useful life (in years)   3 years    
Furniture, fixtures and equipment [Member] | Maximum [Member]        
Property, Plant and Equipment [Line Items]        
Useful life (in years)   15 years