Income Taxes (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010
Income tax provision
Federal	$ 2,581us-gaap_CurrentFederalTaxExpenseBenefit	$ 2,623us-gaap_CurrentFederalTaxExpenseBenefit	$ 2,226us-gaap_CurrentFederalTaxExpenseBenefit
State	495	437	410
Total current income tax provision	3,076us-gaap_CurrentIncomeTaxExpenseBenefit	3,060us-gaap_CurrentIncomeTaxExpenseBenefit	2,636us-gaap_CurrentIncomeTaxExpenseBenefit
Federal	(43)	(115)	(182)
State	0	(17)	(18)
Total deferred income tax provision	(43)us-gaap_DeferredIncomeTaxExpenseBenefit	(132)us-gaap_DeferredIncomeTaxExpenseBenefit	(200)us-gaap_DeferredIncomeTaxExpenseBenefit
Total	3,033us-gaap_IncomeTaxExpenseBenefit	2,928us-gaap_IncomeTaxExpenseBenefit	2,436us-gaap_IncomeTaxExpenseBenefit
Reconciliation of the statutory income tax rate to the Company's effective income tax rate
Statutory income tax rate	35.00%	35.00%	35.00%
State income taxes, net of federal tax benefit	4.30%	4.00%	3.90%
Other	0.20%	(0.10%)	(0.30%)
Effective income tax rate	39.50%	38.90%	38.60%
Deferred tax assets:
Lease and rents	396cvs_DeferredTaxAssetsLeaseAndRents	344cvs_DeferredTaxAssetsLeaseAndRents
Employee benefits	311	213
Allowance for doubtful accounts	164	172
Retirement benefits	80	79
Net operating losses	74	10
Depreciation	0	192
Deferred Tax Assets, Deferred Income	261us-gaap_DeferredTaxAssetsDeferredIncome	220us-gaap_DeferredTaxAssetsDeferredIncome
Other	297us-gaap_DeferredTaxAssetsOther	378us-gaap_DeferredTaxAssetsOther
Valuation allowance	(5)	(3)
Total deferred tax assets	1,578us-gaap_DeferredTaxAssetsGross	1,605us-gaap_DeferredTaxAssetsGross
Deferred tax liabilities:
Inventories	(18)	(69)
Depreciation and amortization	(4,572)	(4,512)
Total deferred tax liabilities	(4,590)us-gaap_DeferredIncomeTaxLiabilities	(4,581)us-gaap_DeferredIncomeTaxLiabilities
Net deferred tax liabilities	(3,012)us-gaap_DeferredTaxAssetsLiabilitiesNet	(2,976)us-gaap_DeferredTaxAssetsLiabilitiesNet
Net deferred tax assets (liabilities) presented on the consolidated balance sheets
Deferred tax assets—current	985us-gaap_DeferredTaxAssetsNetCurrent	902us-gaap_DeferredTaxAssetsNetCurrent
Deferred tax assets—noncurrent (included in other assets)	39us-gaap_DeferredTaxAssetsNetNoncurrent	23us-gaap_DeferredTaxAssetsNetNoncurrent
Deferred tax liabilities—noncurrent	(4,036)	(3,901)
Net deferred tax liabilities	(3,012)us-gaap_DeferredTaxLiabilities	(2,976)us-gaap_DeferredTaxLiabilities
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Beginning balance	117us-gaap_UnrecognizedTaxBenefits	80us-gaap_UnrecognizedTaxBenefits		38us-gaap_UnrecognizedTaxBenefits
Additions based on tax positions related to the current year	32	19	15
Additions based on tax positions related to prior years	70	37	42
Reductions for tax positions of prior years	(15)	(1)	(2)
Expiration of statutes of limitation	(15)	(17)	(12)
Settlements	(1)	(1)	(1)
Ending balance	188us-gaap_UnrecognizedTaxBenefits	117us-gaap_UnrecognizedTaxBenefits	80us-gaap_UnrecognizedTaxBenefits	38us-gaap_UnrecognizedTaxBenefits
Utilization or reduction of the company's reserve for uncertain tax positions over the next twelve months	11
Interest recognized related to unrecognized tax benefits	6	4
Accrued interest and penalties related to unrecognized tax benefits	11	10
Unrecognized tax benefits that would impact effective tax rate	$ 170

The tax effect as of the balance sheet date of the amount of the estimated future tax deductions attributable to lease and rents which can only be realized if sufficient taxable income is generated in future periods to enable the deduction to be taken.

No definition available.