Postretirement Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Summary of the funded status of our postretirement benefit plans and the presentation of such balances within our Consolidated Balance Sheet
Fair value of plan assets	$ 192	$ 195
Projected benefit obligation	522	474
Funded status	(330)	(279)
Amounts reported within:
Accrued liabilities	(14)	(13)
Non-current liabilities	(316)	(267)
Pension [Member]
Summary of the funded status of our postretirement benefit plans and the presentation of such balances within our Consolidated Balance Sheet
Fair value of plan assets	184	187	176
Projected benefit obligation	330	299	280
Funded status	(146)	(112)
Amounts reported within:
Accrued liabilities	(4)	(3)
Non-current liabilities	(142)	(109)
Other Benefits [Member]
Summary of the funded status of our postretirement benefit plans and the presentation of such balances within our Consolidated Balance Sheet
Fair value of plan assets	8	8	8
Projected benefit obligation	192	175	171
Funded status	(184)	(167)
Amounts reported within:
Accrued liabilities	(10)	(10)
Non-current liabilities	$ (174)	$ (158)