Income Taxes (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Deferred tax assets:
Employee benefits	$ 154	$ 98
Settlement costs	498	456
State and local income taxes	18	14
Litigation and legal	7	36
Other	8	10
Gross deferred tax assets	685	614
Deferred tax liabilities:
Depreciation	(57)	(52)
Inventory	(6)	(21)
Federal effect of state deferred taxes	(33)	(32)
Gross deferred tax liabilities	(96)	(105)
Net deferred tax assets	$ 589	$ 509