Consolidated Statements of Shareholders' Equity Statement - USD ($) $ in Thousands	Total	Preferred Stock Including Additional Paid in Capital [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]	Total Shareholders' Equity [Member]
Balance at Dec. 31, 2012		$ 55,407	$ 543	$ 759,214	$ 52,511	$ (250,965)	$ 616,710
Stock issuance		54,459	7	7,548			62,014
Stock Issued During Period, Shares, Restricted Stock Award, Gross			3	2,376			2,379
Adjustments for tax withholding on share-based compensation			1	545			(546)
Stock issuance costs amortization		(208)		(119)			(327)
Common stock repurchased			(9)	(6,924)			(6,933)
Net income	$ 68,069					68,069	68,069
Dividends on preferred stock						(7,902)	(7,902)
Dividends on common stock						(61,261)	(61,261)
Other comprehensive income (loss)	(86,327)				(86,327)		(86,327)
Balance at Dec. 31, 2013		109,658	543	761,550	(33,816)	(252,059)	585,876
Stock issuance		0	1	251			252
Stock Issued During Period, Shares, Restricted Stock Award, Gross			4	2,715			2,719
Adjustments for tax withholding on share-based compensation			1	506			(507)
Stock issuance costs amortization				(75)			(75)
Net income	27,806					27,806	27,806
Dividends on preferred stock						(9,176)	(9,176)
Dividends on common stock						(54,725)	(54,725)
Other comprehensive income (loss)	55,132				55,132		55,132
Balance at Dec. 31, 2014	607,302	109,658	547	763,935	21,316	(288,154)	607,302
Stock issuance		0	0	166			166
Stock Issued During Period, Shares, Restricted Stock Award, Gross			3	2,962			2,965
Adjustments for tax withholding on share-based compensation			1	556			(557)
Stock issuance costs amortization				(37)			(37)
Common stock repurchased			(59)	(41,112)			(41,171)
Net income	16,544					16,544	16,544
Dividends on preferred stock						(9,176)	(9,176)
Dividends on common stock						(49,927)	(49,927)
Other comprehensive income (loss)	(34,084)				(34,084)		(34,084)
Balance at Dec. 31, 2015	$ 492,025	$ 109,658	$ 490	$ 725,358	$ (12,768)	$ (330,713)	$ 492,025