Condensed Consolidated Statements of Stockholders' Equity and Comprehensive Income (Unaudited) (USD $) In Thousands, except Share data	Total	Common Stock	Paid-in Capital	Retained Earnings Substantially Restricted	Accumulated Other Comprehensive (Loss) Income
Beginning Balance at Dec. 31, 2009	$ 685,890	$ 616	$ 497,493	$ 188,129	$ (348)
Beginning Balance, shares at Dec. 31, 2009		61,619,803
Comprehensive income:
Net earnings	42,330			42,330
Unrealized gain on securities, net of reclassification adjustment and taxes	876				876
Total comprehensive income	43,206
Cash dividends declared ($0.26 per share in 2011 and $0.52 per share in 2010)	(37,396)			(37,396)
Public offering of stock issued	145,596	103	145,493
Public offering of stock issued, shares		10,291,465
Stock options exercised	58		58
Stock options exercised, shares		3,805
Stock based compensation and related taxes	850		850
Ending Balance at Dec. 31, 2010	838,204	719	643,894	193,063	528
Ending Balance, shares at Dec. 31, 2010	71,915,073	71,915,073
Comprehensive income:
Net earnings	22,171			22,171
Unrealized gain on securities, net of reclassification adjustment and taxes	24,111				24,111
Total comprehensive income	46,282
Cash dividends declared ($0.26 per share in 2011 and $0.52 per share in 2010)	(18,698)			(18,698)
Stock based compensation and related taxes	(1,016)		(1,016)
Ending Balance at Jun. 30, 2011	$ 864,772	$ 719	$ 642,878	$ 196,536	$ 24,639
Ending Balance, shares at Jun. 30, 2011	71,915,073	71,915,073