Employee Retirement Plans (Details1) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Consolidated Balance Sheet
Accrued liabilities	$ 32	$ 43
Summary of Accumulated other Comprehensive Income Before income Taxes
Net loss	14
Qualified [Member]
Consolidated Balance Sheet
Accrued liabilities	(3)	(3)
Deferred income taxes and other	(436)	(356)
Total net liability	(439)	(359)
Summary of Accumulated other Comprehensive Income Before income Taxes
Net loss	424	326
Net transition obligation	1	1
Net prior service cost	(1)	(1)
Total	424	326
Information About Plan Assets
Projected benefit obligation	943	868
Accumulated benefit obligation	859	866
Fair value of plan assets	504	509
Non-Qualified [Member]
Consolidated Balance Sheet
Accrued liabilities	(12)	(11)
Deferred income taxes and other	(162)	(152)
Total net liability	(174)	(163)
Summary of Accumulated other Comprehensive Income Before income Taxes
Net loss	43	31
Net transition obligation	0	0
Net prior service cost	0	0
Total	43	31
Information About Plan Assets
Projected benefit obligation	174	163
Accumulated benefit obligation	174	163
Fair value of plan assets	$ 0	$ 0