Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Basic EPS
Net income	$ 47,704	$ 31,428	$ 16,102
Amount allocable to common shareholders	100.00%	90.50%	90.50%
Net income applicable to common stock	47,704	28,427	14,569
Basic weighted average shares outstanding	37,006	33,159	33,264
Basic earnings per share	$ 1.29	$ 0.86	$ 0.44
Diluted EPS
Net income	$ 47,704	$ 31,428	$ 16,102
Basic weighted average shares outstanding	37,006	33,159	33,264
Effect of dilutive shares:
Stock options, restricted stock and warrants	2,602	2,392	1,318
Diluted weighted average shares outstanding	39,608	39,051	38,082
Diluted earnings per share	$ 1.20	$ 0.80	$ 0.42
Common Stock Voting [Member]
Basic EPS
Basic weighted average shares outstanding	34,420	30,573	30,678
Diluted EPS
Basic weighted average shares outstanding	34,420	30,573	30,678
Common Stock Non-Voting [Member]
Basic EPS
Basic weighted average shares outstanding	2,586	2,586	2,586
Diluted EPS
Basic weighted average shares outstanding	2,586	2,586	2,586
Series B Preferred Stock [Member]
Effect of dilutive shares:
Series B Preferred Stock		3,500	3,500