Share-Based Compensation (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based compensation disclosures
Share Based Compensation expense	$ 18,200,000	$ 21,200,000	$ 13,700,000
Tax benefit realized from share based awards	100,000	200,000	100,000
Options
Exercised (in shares)	(1,100,000)	(1,100,000)	(700,000)
Restricted Stock Award
Share-based compensation disclosures
Share Based Compensation expense	14,100,000	13,400,000	10,500,000
Option to purchase common stock available for grant	14,300,000
Vesting period of shares	4 years
Restricted Stock Award | Maximum
Share-based compensation disclosures
Vesting period of shares	5 years
Stock options
Share-based compensation disclosures
Option to purchase common stock available for grant	14,300,000	15,500,000
Vesting period of shares	10 years
Options
Options outstanding at the beginning of the period (in shares)	27,870,000
Granted (in shares)	658,000	930,753	32,115
Exercised (in shares)	(1,151,000)
Surrendered (in shares)	(4,563,000)
Forfeited (in shares)	(350,000)
Options outstanding at the end of the period (in shares)	22,464,000	27,870,000
Options exercisable at the end of the period (in shares)	20,837,000	24,939,000	24,900,000
Weighted Average Exercise Price
Options outstanding at the beginning of the period (in dollars per share)	$ 18.94
Granted (in dollars per share)	$ 21.82
Exercised (in dollars per share)	$ 12.42
Surrendered (in dollars per share)	$ 13.52
Forfeited (in dollars per share)	$ 15.07
Options outstanding at the end of the period (in dollars per share)	$ 20.53	$ 18.94
Options exercisable at the end of the period (in dollars per share)	$ 20.99	$ 19.83	$ 20.19
Weighted Average Remaining Contractual Term
Options outstanding at the end of the period	3 years 7 months 20 days	4 years
Options exercisable at the end of the period	3 years 3 months 29 days
Aggregate Intrinsic Value
Options outstanding at the end of the period (in dollars)	36,075,000
Options exercisable at the end of the period (in dollars)	$ 31,429,000
Stock options | Minimum
Share-based compensation disclosures
Vesting period of shares	3 years
Stock options | Maximum
Share-based compensation disclosures
Vesting period of shares	5 years