Stock-Based Incentive Compensation Plans (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Employee service share-based compensation, aggregate disclosures [Abstract]
Compensation expense	$ 22	$ 16	$ 13
Recognized tax benefit	8	6	5
Unrecognized stock-based incentive compensation expense	28	24	21
Executive long term incentive awards, aggregate disclosures [Abstract]
Vesting period (in years)	3	3	3
Stock options [Member]
Employee service share-based compensation, aggregate disclosures [Abstract]
Compensation expense	8	5	6
Unrecognized stock-based incentive compensation expense	6	4	6
Weighted average period (in years)	1.7	1.8	1.7
Executive long term incentive awards, aggregate disclosures [Abstract]
Percentage of total awards granted during the year for participating executive officers	33.00%	34.00%	40.00%
Options granted for certain of our executive officers (in shares)	459,093	301,524	609,175
Assumptions used for stock-based incentive compensation plans [Abstract]
Dividend yield	1.20%	1.30%	1.80%
Expected volatility	48.50%	72.50%	78.70%
Risk-free interest rate, minimum	1.40%	2.70%	1.50%
Risk-free interest rate, maximum	2.90%	3.30%	3.20%
Expected life (in years)	6.7	6.3	5.8
Weighted-average fair value per option granted (in dollars per share)	$ 13.88	$ 16.91	$ 9.47
Stock Options With Performance Conditions [Member]
Summary of activity for stock options [Roll Forward]
Outstanding as of beginning of year (in shares)	1,948,923
Granted - original (in shares)	95,516
Exercised (includes shares tendered) (in shares)	(7,662)
Forfeited or expired (in shares)	(187,329)
Outstanding as of end of year (in shares)	1,849,448	1,948,923
Vested or expected to vest as of end of year (in shares)	1,236,345
Exercisable as of end of year (in shares)	1,734,930
Summary of activity for stock options, additional disclosures [Abstract]
Weighted average exercise price as of beginning of year (in dollars per share)	$ 49.03
Weighted average exercise price granted - original (in dollars per share)	$ 29.97
Weighted average exercise price exercised (includes shares tendered) (in dollars per share)	$ 24.15
Weighted average exercise price forfeited or expired (in dollars per share)	$ 48.60
Weighted average exercise price outstanding as of end of year (in dollars per share)	$ 48.19	$ 49.03
Weighted average exercise price vested or expected to vest as of end of year (in dollars per share)	$ 51.01
Weighted average exercise price exercisable as of end of year (in dollars per share)	$ 49.46
Weighted average remaining contractual term outstanding as of end of year (in years)	1.09
Weighted average remaining contractual term vested or expected to vest as of end of year (in years)	1.26
Weighted average remaining contractual term exercisable as of end of year (in years)	0.94
Aggregate intrinsic value outstanding as of end of year	0
Aggregate intrinsic value vested or expected to vest as of end of year	0
Aggregate intrinsic value exercisable as of end of year	0
Total intrinsic value of options exercised	0	0	0
Total fair value of options vested	2	9	1
Stock Options With Service Conditions [Member]
Summary of activity for stock options [Roll Forward]
Outstanding as of beginning of year (in shares)	7,755,483
Granted - original (in shares)	491,653
Exercised (includes shares tendered) (in shares)	(24,096)
Forfeited or expired (in shares)	(1,572,482)
Outstanding as of end of year (in shares)	6,650,558	7,755,483
Vested or expected to vest as of end of year (in shares)	6,384,696
Exercisable as of end of year (in shares)	5,969,616
Summary of activity for stock options, additional disclosures [Abstract]
Weighted average exercise price as of beginning of year (in dollars per share)	$ 47.20
Weighted average exercise price granted - original (in dollars per share)	$ 30.65
Weighted average exercise price exercised (includes shares tendered) (in dollars per share)	$ 17.62
Weighted average exercise price forfeited or expired (in dollars per share)	$ 44.47
Weighted average exercise price outstanding as of end of year (in dollars per share)	$ 46.73	$ 47.20
Weighted average exercise price vested or expected to vest as of end of year (in dollars per share)	$ 47.59
Weighted average exercise price exercisable as of end of year (in dollars per share)	$ 48.95
Weighted average remaining contractual term outstanding as of end of year (in years)	3.66
Weighted average remaining contractual term vested or expected to vest as of end of year (in years)	3.48
Weighted average remaining contractual term exercisable as of end of year (in years)	3.08
Aggregate intrinsic value outstanding as of end of year	2
Aggregate intrinsic value vested or expected to vest as of end of year	1
Aggregate intrinsic value exercisable as of end of year	1
Total intrinsic value of options exercised	0	0	0
Total fair value of options vested	7	4	8
Performance Shares [Member]
Employee service share-based compensation, aggregate disclosures [Abstract]
Compensation expense	2	(1)	(2)
Unrecognized stock-based incentive compensation expense	4	0	0
Weighted average period (in years)	2.0	0	1.0
Executive long term incentive awards, aggregate disclosures [Abstract]
Percentage of total awards granted during the year for participating executive officers	33.00%
Percentage of target award opportunities, minimum	0.00%
Percentage of target award opportunities, maximum	200.00%
Restricted stock units granted for certain of our executive officers (in shares)	215,137
Assumptions used for stock-based incentive compensation plans [Abstract]
Weighted-average grant date fair value, granted (in dollars per share)	$ 31.03
Summary of activity for performance shares [Roll Forward]
Performance shares as of beginning of year (in shares)	210,695
Forfeited (in shares)	(228,383)
Performance shares as of end of year (in shares)	197,449	210,695
Performance shares, additional disclosures [Abstract]
Weighted-average grant date fair value, outstanding as of beginning of year (in dollars per share)	$ 42.28
Weighted-average grant date fair value, granted (in dollars per share)	$ 31.03
Weighted-average grant date fair value, forfeited (in dollars per share)	$ 41.41
Weighted-average grant date fair value, outstanding as of end of year (in dollars per share)	$ 31.02	$ 42.28
Performance Cash Awards [Member]
Executive long term incentive awards, aggregate disclosures [Abstract]
Percentage of total awards granted during the year for participating executive officers			33.00%
Stock Appreciation Rights [Member]
Employee service share-based compensation, aggregate disclosures [Abstract]
Unrecognized stock-based incentive compensation expense	1	1	2
Weighted average period (in years)	3.4	3.7	4.1
Stock appreciation rights [Abstract]
SARs liability	1	1	1
Payment for SARs exercised	0	0	0
Assumptions used for stock-based incentive compensation plans [Abstract]
Dividend yield	1.90%	2.40%	0.20%
Expected volatility	39.10%	38.20%	106.00%
Risk-free interest rate	2.20%	1.80%	2.40%
Expected life (in years)	5.0	5.0	5.0
Weighted-average grant date fair value, granted (in dollars per share)	$ 9.41	$ 7.81	$ 12.47
Summary of activity for stock options [Roll Forward]
Outstanding as of beginning of year (in shares)	715,631
Granted - original (in shares)	106,950
Exercised (includes shares tendered) (in shares)	(8,818)
Forfeited or expired (in shares)	(142,438)
Outstanding as of end of year (in shares)	671,325	715,631
Vested or expected to vest as of end of year (in shares)	648,545
Exercisable as of end of year (in shares)	480,041
Summary of activity for stock options, additional disclosures [Abstract]
Weighted average exercise price as of beginning of year (in dollars per share)	$ 47.02
Weighted average exercise price granted - original (in dollars per share)	$ 29.97
Weighted average exercise price exercised (includes shares tendered) (in dollars per share)	$ 16.53
Weighted average exercise price forfeited or expired (in dollars per share)	$ 54.14
Weighted average exercise price outstanding as of end of year (in dollars per share)	$ 43.26	$ 47.02
Weighted average exercise price vested or expected to vest as of end of year (in dollars per share)	$ 43.78
Weighted average exercise price exercisable as of end of year (in dollars per share)	$ 49.44
Weighted average remaining contractual term outstanding as of end of year (in years)	1.89
Weighted average remaining contractual term vested or expected to vest as of end of year (in years)	1.84
Weighted average remaining contractual term exercisable as of end of year (in years)	1.30
Aggregate intrinsic value outstanding as of end of year	0
Aggregate intrinsic value vested or expected to vest as of end of year	0
Aggregate intrinsic value exercisable as of end of year	0
Performance shares, additional disclosures [Abstract]
Weighted-average grant date fair value, granted (in dollars per share)	$ 9.41	$ 7.81	$ 12.47
Restricted Stock Units And Awards [Member]
Employee service share-based compensation, aggregate disclosures [Abstract]
Compensation expense	12	12	9
Unrecognized stock-based incentive compensation expense	$ 17	$ 19	$ 13
Weighted average period (in years)	1.7	1.9	2.2
Restricted Stock Units [Member]
Executive long term incentive awards, aggregate disclosures [Abstract]
Percentage of total awards granted during the year for participating executive officers	34.00%	66.00%	27.00%
Restricted stock units granted for certain of our executive officers (in shares)	221,813	575,353	902,269
Performance shares, additional disclosures [Abstract]
Outstanding as of beginning of year (in shares)	1,563,928
Granted (in shares)	540,394
Vested (in shares)	(206,294)
Forfeited (in shares)	(118,675)
Outstanding as of end of year (in shares)	1,779,353	1,563,928
Restricted stock units, additional disclosures [Abstract]
Weighted-average grant date fair value, RSU, outstanding as of beginning of period (in dollars per share)	$ 23.38
Weighted-average grant date fair value, granted (in dollars per share)	$ 30.20
Weighted-average grant date fair value, vested (in dollars per share)	$ 33.36
Weighted-average grant date fair value, forfeited (in dollars per share)	$ 25.09
Weighted-average grant date fair value, outstanding as of end of year (in dollars per share)	$ 23.94	$ 23.38