Income Taxes (Schedule of Difference in Income Tax Effects Comprising Company's Deferred Income Tax Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Inventories	$ 607	$ 623
Other accrued expenses	288	212
Depreciation and amortization	46	41
State income taxes	53	54
Share-based compensation	101	115
Net operating loss carryforwards	124	90
Other	107	97
Total deferred income tax assets	1,326	1,232
Less valuation allowances	(39)	(33)
Total deferred income tax assets after valuation allowances	1,287	1,199
Depreciation and amortization	(668)	(450)
Other	(102)	(57)
Total deferred income tax liabilities	(770)	(507)
Net deferred income tax assets	517	692
Current assets— Prepaid expenses and other current assets	880	811
Noncurrent assets—Other	34	63
Noncurrent liabilities—Other liabilities	(397)	(182)
Accrued interest and penalties reported as accrued expenses and other liabilities	$ 34	$ 49