Consolidated Statements of Changes in Stockholders Equity (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	Preferred stock	Common stock	Retained earnings	Accumulated other comprehensive income
Beginning Balance at Dec. 31, 2010	$ 736,802	$ 50,000	$ 264,174	$ 413,253	$ 9,375
Comprehensive income:
Net income	9,506	0	0	9,506	0
Other comprehensive income, net of tax	273	0	0	0	273
Common stock transactions:
Common shares purchased and retired 17,904 and 12,056 in 2012 and 2011 respectively	(164)	0	(164)	0	0
Non-vested common shares issued 122,912 and 130,904 in 2012 and 2011 respectively	0	0	0	0	0
1,556 and 1,911 non-vested common shares forfeited in 2012 and 2011 respectively	(7)	0	(7)	0	0
Non-vested liability awards vesting during period	195	0	195	0	0
100,991 and 43,622 stock options exercised, net of 37,397 and 104,050 shares tendered in payment of option price and income tax withholding amounts in 2012 and 2011 respectively	37	0	37	0	0
Tax benefit of stock-based compensation	257	0	257	0	0
Stock-based compensation expense	440	0	440	0	0
Cash dividends declared:
Common ($0.12 and $0.1125 per share in 2012 and 2011 respectively)	(4,798)	0	0	(4,798)	0
Preferred (6.75% per share in 2012 and 2011)	(844)	0	0	(844)	0
Ending Balance at Mar. 31, 2011	741,697	50,000	264,932	417,117	9,648
Beginning Balance at Dec. 31, 2011	771,020	50,000	266,842	435,144	19,034
Comprehensive income:
Net income	12,214	0	0	12,214	0
Other comprehensive income, net of tax	460	0	0	0	460
Common stock transactions:
Common shares purchased and retired 17,904 and 12,056 in 2012 and 2011 respectively	(256)	0	(256)	0	0
Common shares issued 2,358 and 0 in 2012 and 2011 respectively	0	0	0	0	0
Non-vested common shares issued 122,912 and 130,904 in 2012 and 2011 respectively	0	0	0	0	0
1,556 and 1,911 non-vested common shares forfeited in 2012 and 2011 respectively	0	0	0	0	0
100,991 and 43,622 stock options exercised, net of 37,397 and 104,050 shares tendered in payment of option price and income tax withholding amounts in 2012 and 2011 respectively	1,068	0	1,068	0	0
Tax benefit of stock-based compensation	114	0	114	0	0
Stock-based compensation expense	643	0	643	0	0
Cash dividends declared:
Common ($0.12 and $0.1125 per share in 2012 and 2011 respectively)	(5,135)	0	0	(5,135)	0
Preferred (6.75% per share in 2012 and 2011)	(853)	0	0	(853)	0
Ending Balance at Mar. 31, 2012	$ 779,275	$ 50,000	$ 268,411	$ 441,370	$ 19,494