Employee Benefit Plans - Stock Options (Details) (Stock Options [Member], USD $)	12 Months Ended
	Dec. 31, 2011 Years	Dec. 31, 2010	Dec. 31, 2009
Stock Options [Member]
Options Outstanding [Roll Forward]
Options outstanding at January 1, 2011	5,604,916
Options outstanding, weighted average exercise price, beginning balance	$ 13.69
Options granted, shares	1,406,108
Options granted, weighted average exercise price	$ 13.12
Options exercised, shares	(462,369)
Options exercised, weighted average exercise price	$ 8.18
Options cancelled or forfeited, shares	(1,211,726)
Options cancelled or forfeited, weighted average exercise price	$ 9.56
Options outstanding at December 31, 2011	5,336,929	5,604,916
Options outstanding, weighted average exercise price, ending balance	$ 12.84	$ 13.69
Options outstanding, weighted average remaining contractual term (years)	6.23
Options outstanding, aggregate intrinsic value	$ 2,300,000
Options Vested and Expected to Vest [Abstract]
Vested or expected to vest at December 31, 2011, shares	2,202,681
Vested or expected to vest at December 31, 2011, weighted average exercise price	$ 11.55
Vested or expected to vest at December 31, 2011, weighted average remaining contractual term (years)	7.13
Vested or expected to vest at December 31, 2011, aggregate intrinsic value	1,000,000
Options - Additional Disclosures [Abstract]
Options exercisable at December 31, 2011, shares	2,553,822
Options exercisable at December 31, 2011, weighted average exercise price	$ 14.30
Options exercisable at December 31, 2011, weighted average remaining contractual term (years)	5.23
Options exercisable at December 31, 2011, aggregate intrinsic value	1,100,000
Weighted-average grant date fair value	$ 6.65	$ 5.73	$ 6.77
Total intrinsic value of options exercised	3,000,000	7,200,000	100,000
Net proceeds from exercise of stock options	3,700,000	10,900,000	600,000
Unamortized compensation costs	$ 14,284,000
Unamortized compensation costs period of recognition (years)	3