Consolidated Statements of Changes in Equity (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	Preferred Stock [Member]	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
Balance at beginning of period at Dec. 31, 2011	$ 352,893	$ 81,698	$ 16,612	$ 43,333	$ 198,182	$ 12,147	$ (1,754)	$ 2,675
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	48,086				40,385	7,724		(23)
Comprehensive income	48,063
Cash dividends declared:
Preferred	(2,989)				(2,989)
Common	(4,945)				(4,945)
Purchase of shares of common stock	(2,485)						(2,485)
Issuance of shares of common stock	2,575			686			1,889
Commitments to issue common stock	1,611			1,611
Balance at end of period at Sep. 30, 2012	394,746	81,698	16,612	45,630	230,633	19,871	(2,350)	2,652
Balance at beginning of period at Dec. 31, 2012	404,539	81,698	16,828	50,359	236,279	16,641	0	2,734
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	(1,606)
Comprehensive income	(1,542)				28,854	(30,460)		64
Cash dividends declared:
Preferred	(889)				(889)
Common	(5,072)				(5,072)
Purchase of noncontrolling interest	(2,798)							(2,798)
Purchase of shares of common stock	(1,601)						(1,601)
Issuance of shares of common stock	2,428		125	744			1,559
Commitments to issue common stock	1,538			1,538
Balance at end of period at Sep. 30, 2013	$ 396,603	$ 81,698	$ 16,953	$ 52,641	$ 259,172	$ (13,819)	$ (42)	$ 0