Consolidated Statements of Shareholders' Equity Statement (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Total shareholders' equity	$ 585,876	$ 616,710	$ 371,349	$ 292,357
Stock issuance	62,014	179,686	95,424
Granting and vesting of restricted stock	2,379	1,723	1,198
Capitalized expenses associated with stock issuances	327	(411)	(142)
Common stock repurchased	(6,933)	(921)
Common stock forfeited for payroll tax purposes	(546)
Net Income	68,069	74,042	39,812
Dividends on preferred stock	(7,902)	(2,036)
Dividends on common stock	(61,261)	(62,488)	(43,988)
Other comprehensive income (loss)	(86,327)	55,766	(13,312)
Preferred Stock Including Additional Paid in Capital [Member]
Total shareholders' equity	109,658	55,407	0	0
Stock issuance	54,459	55,689
Capitalized expenses associated with stock issuances	208	(282)
Common Stock [Member]
Total shareholders' equity	543	543	404	303
Stock issuance	7	138	97
Granting and vesting of restricted stock	3	2	4
Common stock repurchased	(9)	(1)
Common stock forfeited for payroll tax purposes	(1)
Additional Paid-in Capital [Member]
Total shareholders' equity	761,550	759,214	634,683	538,304
Stock issuance	7,548	123,859	95,327
Granting and vesting of restricted stock	2,376	1,721	1,194
Capitalized expenses associated with stock issuances	(119)	(129)	(142)
Common stock repurchased	(6,924)	(920)
Common stock forfeited for payroll tax purposes	(545)
Accumulated Other Comprehensive Income (Loss) [Member]
Total shareholders' equity	(33,816)	52,511	(3,255)	10,057
Other comprehensive income (loss)	86,327	55,766	13,312
Accumulated Deficit [Member]
Total shareholders' equity	(252,059)	(250,965)	(260,483)	(256,307)
Net Income	68,069	74,042	39,812
Dividends on preferred stock	(7,902)	(2,036)
Dividends on common stock	$ (61,261)	$ (62,488)	$ (43,988)