Fair Value Measurements (Details 3) (USD $) In Millions, unless otherwise specified	Jun. 30, 2011	Dec. 31, 2010
Short Term Line of Credit | Carrying Amount
Fair value and carrying value of debt instruments
Debt instrument	$ 13	$ 5
Senior secured revolving credit facility (Credit Agreement - long term) | Carrying Amount
Fair value and carrying value of debt instruments
Debt instrument	395	170
10.25% Senior notes due 2014 | Carrying Amount
Fair value and carrying value of debt instruments
Debt instrument	440	439
8.25% Senior subordinated notes due 2016. | Carrying Amount
Fair value and carrying value of debt instruments
Debt instrument	200	200
Carrying Amount
Fair value and carrying value of debt instruments
Debt instrument	1,348	1,114
Carrying Amount | 6.75% Senior notes due 2020
Fair value and carrying value of debt instruments
Debt instrument	300	300
Short Term Line of Credit | Estimated Fair Value
Fair value and carrying value of debt instruments
Debt instrument	13	5
Senior secured revolving credit facility (Credit Agreement - long term) | Estimated Fair Value
Fair value and carrying value of debt instruments
Debt instrument	395	170
10.25% Senior notes due 2014 | Estimated Fair Value
Fair value and carrying value of debt instruments
Debt instrument	513	518
8.25% Senior subordinated notes due 2016. | Estimated Fair Value
Fair value and carrying value of debt instruments
Debt instrument	208	210
Estimated Fair Value
Fair value and carrying value of debt instruments
Debt instrument	1,429	1,206
Estimated Fair Value | 6.75% Senior notes due 2020
Fair value and carrying value of debt instruments
Debt instrument	$ 300	$ 303
8.25% Senior subordinated notes due 2016.
Fair value and carrying value of debt instruments
Interest rate on debt instrument (as a percent)	8.25%	8.25%
10.25% Senior notes due 2014
Fair value and carrying value of debt instruments
Interest rate on debt instrument (as a percent)	10.25%	10.25%
6.75% Senior notes due 2020
Fair value and carrying value of debt instruments
Interest rate on debt instrument (as a percent)	6.75%	6.75%