CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
Balance at beginning of period at Dec. 31, 2013		$ 63,047	$ 20,707	$ 888,161	$ 322,679	$ (78,736)
Total stockholders' equity	1,255,898	56,810	20,897	894,247	340,141	(56,197)
Common stock issued for compensation			6	(6)
Repurchase of common stock			(4)	(242)
Common stock sold
Restricted stock grants			81	(81)
Restricted stock forefeited			0	0
Stock-based compensation				717
Net income (loss)	17,083				17,083
Excess of carrying amount of preferred stock exchanged over fair value of new common stock	379				379
Other comprehensive income (loss), net of tax	22,539					22,539
Common stock issued in exchange of preferred stock-Series A through E			107	5,538
Exchange Of Preferred Stock Series For Common Stock		(6,237)
Reversal of Issuance cost of Series A through E of preferred stock exchanged				213
Issuance Cost Of Common Stock				(53)
Balance at end of period at Mar. 31, 2014	1,255,898	56,810	20,897	894,247	340,141	(56,197)
Balance at beginning of period at Dec. 31, 2014	1,671,743	36,104	21,298	916,067	716,625	(18,351)
Total stockholders' equity	1,705,750	36,104	21,383	917,203	742,271	(11,211)
Common stock issued for compensation			8	(8)
Repurchase of common stock			(5)	(231)
Common stock sold
Restricted stock grants			83	(83)
Restricted stock forefeited			(1)	1
Stock-based compensation				1,457
Net income (loss)	25,646				25,646
Excess of carrying amount of preferred stock exchanged over fair value of new common stock	0				0
Other comprehensive income (loss), net of tax	7,140					7,140
Common stock issued in exchange of preferred stock-Series A through E			0	0
Exchange Of Preferred Stock Series For Common Stock		0
Reversal of Issuance cost of Series A through E of preferred stock exchanged				0
Issuance Cost Of Common Stock				0
Balance at end of period at Mar. 31, 2015	$ 1,705,750	$ 36,104	$ 21,383	$ 917,203	$ 742,271	$ (11,211)