CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss
Balance at the beginning of the period at Dec. 31, 2013	$ 1,519,513	$ 129,796	$ 1,665	$ 894,297	$ 1,930,026	$ (1,398,021)	$ (38,250)
Increase (Decrease) in Stockholders' Equity
Net income	95,916				95,916
Other comprehensive income (loss), net of tax	(27,701)						(27,701)
Dividends on preferred stock	(8,775)				(8,775)
Dividends on common stock	(15,868)				(15,868)
Sales of treasury stock	8,121				(4,595)	12,716
Restricted stock grants	0			(6,472)	(4,160)	10,632
Forfeitures of restricted stock	0			374	275	(649)
Stock-based compensation	8,672			8,658	14
Net tax benefit excess from stock-based compensation	192			192
Balance at the end of the period at Dec. 31, 2014	1,580,070	129,796	1,665	897,049	1,992,833	(1,375,322)	(65,951)
Increase (Decrease) in Stockholders' Equity
Net income	88,075				88,075
Other comprehensive income (loss), net of tax	7,334						7,334
Dividends on preferred stock	(8,775)				(8,775)
Dividends on common stock	(16,081)				(16,081)
Sales of treasury stock	6,168				(3,802)	9,970
Common stock repurchased	(6,869)					(6,869)
Restricted stock units vesting	0			(3,378)	(4,189)	7,567
Restricted stock grants	0			(5,608)	(3,273)	8,881
Forfeitures of restricted stock	0			777	586	(1,363)
Stock-based compensation	11,411			11,394	17
Net tax benefit excess from stock-based compensation	2,115			2,115
Balance at the end of the period at Dec. 31, 2015	1,663,448	129,796	1,665	902,349	2,045,391	(1,357,136)	(58,617)
Increase (Decrease) in Stockholders' Equity
Net income	71,529				71,529
Other comprehensive income (loss), net of tax	1,736						1,736
Dividends on preferred stock	(8,775)				(8,775)
Dividends on common stock	(16,214)				(16,214)
Sales of treasury stock	159				(58)	217
Common stock repurchased	(1,913)					(1,913)
Restricted stock grants	0			(10,329)	(3,823)	14,152
Forfeitures of restricted stock	0			1,341	688	(2,029)
Stock-based compensation	4,103			4,097	6
Balance at the end of the period at Dec. 31, 2016	1,714,073	$ 129,796	$ 1,665	830,417	2,155,785	$ (1,346,709)	$ (56,881)
Increase (Decrease) in Stockholders' Equity
Adjustment to additional paid-in capital and retained earnings upon adoption of ASU 2016-09 as of December 31, 2016	$ 0			$ (67,041)	$ 67,041