Stock Compensation Plans (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 years		Dec. 31, 2010 years		Dec. 31, 2009 years
Share based compensation arrangement by share based payment award fair value assumptions and methodology
Expected term (years)	6.25	[1]	6.25	[1]	5.99	[1]
Interest rate	2.28%	[1]	2.58%	[1]	2.39%	[1]
Volatility	49.50%	[1]	50.50%	[1]	79.60%	[1]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested at January 1	302,240
Granted	161,876
Vested	(163,593)
Forfeited	(5,063)
Unvested at December 31	295,460		302,240
Share-based Compensation [Abstract]
Stock-based compensation expense (income) recognized	$ 18		$ 26		$ 29
Tax impact	0		0		(2)
After-tax stock-based compensation expense (income)	18		26		27
Cash payments to settle SARs and Performance share units	0		0		0
Cash received from stock option exercises	$ 8		$ 1		$ 2

[1] We review the assumptions used in our Black-Scholes model in conjunction with estimating the grant date fair value of the annual grants of stock-based awards by our Board of Directors.