Consolidated Statements of Changes in Equity and Comprehensive Income (USD $) In Thousands, unless otherwise specified	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Period Start at Dec. 31, 2010	$ 331,784	$ 78,483	$ 16,612	$ 44,628	$ 184,525	$ 8,517	$ (3,674)	$ 2,693
Comprehensive income	2,693				4,237	(1,528)		(16)
Cumulative preferred dividends accrued and discount accretion	0	315			(315)
Cash dividends declared:
Preferred, $12.50 per share	(1,021)				(1,021)
Common, $0.10 per share	(1,638)				(1,638)
Purchase of shares of common stock	(289)						(289)
Issuance of shares of common stock	551			(354)			905
Commitments to issue common stock	312			312
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Period End at Mar. 31, 2011	332,392	78,798	16,612	44,586	185,788	6,989	(3,058)	2,677
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Period Start at Dec. 31, 2011	352,893	81,698	16,612	43,333	198,182	12,147	(1,754)	2,675
Comprehensive income	15,086				12,841	2,271		(26)
Cumulative preferred dividends accrued and discount accretion
Cash dividends declared:
Preferred, $12.50 per share	(1,021)				(1,021)
Common, $0.10 per share	(1,649)				(1,649)
Purchase of shares of common stock	(308)						(308)
Issuance of shares of common stock	283			(207)			490
Commitments to issue common stock	759			759
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Period End at Mar. 31, 2012	$ 366,043	$ 81,698	$ 16,612	$ 43,885	$ 208,353	$ 14,418	$ (1,572)	$ 2,649