Stock-Based Compensation (Details 3) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011
Service based restricted stock [Member]
Restricted stock units
Unvested RSUs at January 1, 2011	8,415
Granted, Number of units	8,953
Vested, Number of units	(2,333)
Forfeited, Number of units	(2,950)
Unvested RSUs at December 31, 2011	12,085
Unvested RSUs, Weighted-average grant date fair Value, Beginning of period	$ 5.56
Granted, Weighted-average grant date fair value	$ 6.23
Vested, Weighted-average grant date fair value	$ 5.93
Forfeited, Weighted-average grant date fair value	$ 5.73
Unvested RSUs, Weighted-average grant date fair value, End of period	$ 5.94
Performance-based Restricted Stock Units [Member]
Restricted stock units
Unvested RSUs at January 1, 2011	2,894
Granted, Number of units	4,224
Vested, Number of units	(1,022)
Forfeited, Number of units	(1,367)
Unvested RSUs at December 31, 2011	4,729
Unvested RSUs, Weighted-average grant date fair Value, Beginning of period	$ 5.51
Granted, Weighted-average grant date fair value	$ 6.18
Vested, Weighted-average grant date fair value	$ 5.51
Forfeited, Weighted-average grant date fair value	$ 5.95
Unvested RSUs, Weighted-average grant date fair value, End of period	$ 5.98