Net Income per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Computation of basic and diluted net income per common share
Net income applicable to common shares	$ 12,039	$ 2,558	$ 20,276	$ 2,695
Weighted average number of common shares outstanding	155,631	155,096	155,587	154,385
Weighted average number of diluted common shares outstanding	162,575	156,553	162,594	156,058
Basic net income per share	$ 0.08	$ 0.02	$ 0.13	$ 0.02
Diluted net income per share	$ 0.08	$ 0.02	$ 0.13	$ 0.02
Stock Award One [Member]
Computation of basic and diluted net income per common share
Effect of convertible preferred stock and convertible preferred stock	879	1,457	942	1,673
Stock Award Two [Member]
Computation of basic and diluted net income per common share
Effect of convertible preferred stock and convertible preferred stock	6,065		6,065
Series D Preferred Stock [Member]
Computation of basic and diluted net income per common share
Income impact of assumed Series D Preferred Stock conversion	338		676
Net income after assumed Series D Preferred Stock conversion	$ 12,377	$ 2,558	$ 20,952	$ 2,695