CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($)		Total		Preferred Stock [Member]	Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
Total stockholders' equity				$ 63,047,000	$ 20,707,000	$ 888,161,000	$ 322,679,000	$ (78,736,000)
Total stockholders' equity		$ 1,671,743,000		36,104,000	21,298,000	888,161,000	322,679,000	(78,736,000)
Balance at beginning of year at Dec. 31, 2013				63,047,000	20,707,000	888,161,000	322,679,000	(78,736,000)
Exchange of preferred stock-Series A through E		(26,022,000)		(26,943,000)
Common stock issued in exchange for Series A through E preferred stock					459,000	23,904,000
Restricted Stock Forfeited					(4,000)	4,000
Restricted stock grants					122,000	(122,000)
Common stock issued as compensation					32,000	(32,000)
Common stock withheld for taxes					(18,000)	(928,000)
Stock-based compensation						4,221,000
Excess of carrying amount of Series A through E preferred stock exchanged over fair value of new shares of common stock		1,659,000	[1]				1,659,000
Reversal of Issuance cost of Series A through E of preferred stock exchanged						921,000
Issuance costs of common stock issued in exchange for Series A through E preferred stock						(62,000)
Net income		392,287,000					392,287,000
Dividends on preferred stock		0					0
Other comprehensive (loss) income, net of tax		60,385,000						60,385,000
Common stock issued in exchange for trust preferred securities		0			0	0
Balance at end of year at Dec. 31, 2014		1,671,743,000		36,104,000	21,298,000	916,067,000	716,625,000	(18,351,000)
Total stockholders' equity		1,671,743,000		36,104,000	21,298,000	916,067,000	716,625,000	(18,351,000)
Total stockholders' equity		1,671,743,000		36,104,000	21,298,000	926,348,000	737,922,000	(27,749,000)
Exchange of preferred stock-Series A through E		0		0
Common stock issued in exchange for Series A through E preferred stock					0	0
Restricted Stock Forfeited					(2,000)	2,000
Restricted stock grants					102,000	(102,000)
Common stock issued as compensation					48,000	(48,000)
Common stock withheld for taxes					(22,000)	(1,151,000)
Stock-based compensation						6,037,000
Excess of carrying amount of Series A through E preferred stock exchanged over fair value of new shares of common stock	[1]	0					0
Reversal of Issuance cost of Series A through E of preferred stock exchanged						0
Issuance costs of common stock issued in exchange for Series A through E preferred stock						0
Net income		21,297,000					21,297,000
Dividends on preferred stock		0					0
Other comprehensive (loss) income, net of tax		(9,398,000)						(9,398,000)
Common stock issued in exchange for trust preferred securities		5,628,000			85,000	5,543,000
Balance at end of year at Dec. 31, 2015		1,694,134,000		36,104,000	21,509,000	926,348,000	737,922,000	(27,749,000)
Total stockholders' equity		1,694,134,000		36,104,000	21,509,000	926,348,000	737,922,000	(27,749,000)
Total stockholders' equity		1,786,243,000		36,104,000	21,745,000	926,348,000	830,928,000	(34,390,000)
Exchange of preferred stock-Series A through E		0		0
Common stock issued in exchange for Series A through E preferred stock					0	0
Restricted Stock Forfeited					(3,000)	3,000
Restricted stock grants					193,000	(193,000)
Common stock issued as compensation					75,000	(75,000)
Common stock withheld for taxes					(29,000)	(1,103,000)
Stock-based compensation						6,876,000
Excess of carrying amount of Series A through E preferred stock exchanged over fair value of new shares of common stock		0	[1]				0
Reversal of Issuance cost of Series A through E of preferred stock exchanged						0
Issuance costs of common stock issued in exchange for Series A through E preferred stock						0
Net income		93,229,000					93,229,000
Dividends on preferred stock		(223,000)					(223,000)
Other comprehensive (loss) income, net of tax		(6,641,000)						(6,641,000)
Common stock issued in exchange for trust preferred securities		0			0	0
Balance at end of year at Dec. 31, 2016		1,786,243,000		36,104,000	21,745,000	931,856,000	830,928,000	(34,390,000)
Total stockholders' equity		$ 1,786,243,000		$ 36,104,000	$ 21,745,000	$ 931,856,000	$ 830,928,000	$ (34,390,000)

[1] Excess of carrying amount of the Series A through E preferred stock exchanged over the fair value of new common shares issued in 2014.