Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements of Comprehensive Income [Abstract]
Net income before preferred dividends	$ 16,844	$ 15,952	$ 25,570
Investment securities available for sale:
Unrealized gains (losses) arising in period	3,292	4,548	(86)
Reclassification adjustment for net gains realized in earnings	(931)	0	0
Other comprehensive income (loss) before income tax provision (benefit)	2,361	4,548	(86)
Income tax provision (benefit)	827	1,592	(30)
Other comprehensive income (loss), net	1,534	2,956	(56)
Total comprehensive income	$ 18,378	$ 18,908	$ 25,514