Stock Compensation Plans Stock Options (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding	13,528,862		12,787,824
Options granted	2,004,429
Options exercised	(513,910)
Options expired	(140,502)
Options cancelled	(608,979)
Options cancelled Weighted Average Exercise Price	$ 17.34
Vested and expected to vest	13,049,005
Exercisable	9,166,525
Available for grant	6,510,610
Options Outstanding Weighted Average Exercise Price	$ 14.75		$ 14.84
Options granted Weighted Average Exercise Price	$ 12.79
Options exercised Weighted Average Exercise Price	$ 7.98
Options expired Weighted Average Exercise Price	$ 8.89
Vested and expected to vest Weighted Average Exercise Price	$ 14.84
Exercisable Weighted Average Exercise Price	$ 15.92
Weighted Average Remaining Contractual Term (Years)	5 years 6 months
Vested and expected to vest Weighted Average Remaining Contractual Term (Years)	5 years 4 months
Exercisable Weighted Average Remaining Contractual Term (Years)	4 years 1 month
Outstanding Aggregate Intrinsic Value (In millions)	$ 26
Options exercised Aggregate Intrinsic Value (in millions)	2		10		1
Vested and expected to vest Intrinsic Value (in millions)	24
Exercisable Aggregate Intrinsic Value	$ 19
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit	$ 5.52
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit	$ 36.25
Weighted average fair value per share for the stock options	$ 6.33		$ 6.94		$ 6.45
Black-Scholes model assumptions:
Expected term (years)	6 years 3 months	[1]	6 years 3 months	[1]	6 years 3 months	[1]
Interest rate	1.09%	[1]	2.28%	[1]	2.58%	[1]
Volatility	50.83%	[1]	49.50%	[1]	50.50%	[1]
Dividend yield	0.00%	[1]	0.00%	[1]	0.00%	[1]
Grant Date February 27 2012 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding	1,734,582
Exercisable	4,156
Weighted Average Remaining Contractual Term (Years)	9 years 2 months
Exercise Price	$ 12.94
Grant Date February 22 2011 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding	1,311,165
Exercisable	343,417
Weighted Average Remaining Contractual Term (Years)	8 years 2 months
Exercise Price	$ 13.91
Grant Date February 23 2010 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding	1,250,773
Exercisable	665,443
Weighted Average Remaining Contractual Term (Years)	7 years 2 months
Exercise Price	$ 12.74
Grant Date February 26 2009 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding	1,631,988
Exercisable	1,230,591
Weighted Average Remaining Contractual Term (Years)	6 years 2 months
Exercise Price	$ 4.81
Grant Date February 21 2008 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding	1,109,994
Exercisable	1,109,994
Weighted Average Remaining Contractual Term (Years)	5 years 2 months
Exercise Price	$ 26.74
Grant Date February 27 2007 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding	1,239,522
Exercisable	1,239,522
Weighted Average Remaining Contractual Term (Years)	4 years 2 months
Exercise Price	$ 24.71
Grant Date December 6 2005 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding	825,642
Exercisable	825,642
Weighted Average Remaining Contractual Term (Years)	2 years 11 months
Exercise Price	$ 17.15
Grant Date December 9 2004 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding	1,465,881
Exercisable	1,465,881
Weighted Average Remaining Contractual Term (Years)	1 year 11 months
Exercise Price	$ 12.54
Grant Date December 2 2003 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding	682,576
Exercisable	682,576
Weighted Average Remaining Contractual Term (Years)	11 months
Exercise Price	$ 6.81
All Other Grant Dates [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding	2,276,739	[2]
Exercisable	1,599,303	[2]
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Remaining Contractual Term (Years)	5 years
Exercise Price	$ 16.52
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Remaining Contractual Term (Years)	3 years 6 months
Exercise Price	$ 18.27

[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.

[2] Options in the “All other” category had exercise prices ranging from $5.52 to $36.25. The weighted average exercise price for options outstanding and exercisable in that category was $16.52 and $18.27, respectively, while the remaining weighted average contractual term was 5.0 and 3.5 years, respectively.