Consolidated Statements Of Changes In Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2013	$ 6,464,563	$ 1,003,970	$ 4,179,024	$ 1,473,670	$ (192,101)
Balance (in shares) at Dec. 31, 2013			184,677,696
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	398,462			398,462
Other comprehensive income (loss)	64,060				64,060
Stock Issued During Period, Value, New Issues			$ 515,856
Subordinated debt converted to preferred stock	34	41	$ (7)
Stock Issued During Period, Shares, New Issues			17,617,450
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures			719,757
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	28,982		$ 28,982
Dividends on preferred stock	(71,894)			(71,894)
Dividends on common stock	(31,216)			(31,216)
Increase (Decrease) in Deferred Compensation	683			683
Balance at Dec. 31, 2014	7,369,530	1,004,011	$ 4,723,855	1,769,705	(128,041)
Balance (in shares) at Dec. 31, 2014			203,014,903
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	309,471			309,471
Other comprehensive income (loss)	73,429				73,429
Preferred stock redemption	176,049	175,669	$ (3,069)	3,449
Subordinated debt converted to preferred stock	104	148	$ (44)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures			1,402,190
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	39,851		$ 39,851
Dividends on preferred stock	(62,857)			(62,857)
Dividends on common stock	(45,133)			(45,133)
Increase (Decrease) in Deferred Compensation	(827)			(827)
Balance at Dec. 31, 2015	$ 7,507,519	828,490	$ 4,766,731	1,966,910	(54,612)
Balance (in shares) at Dec. 31, 2015	204,417,093		204,417,093
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 469,050			469,050
Other comprehensive income (loss)	(66,969)				(66,969)
Preferred stock redemption	$ (126,144)	(118,889)	$ 2,504	(9,759)
Stock Repurchased During Period, Shares	2,890,000		(2,888,946)
Stock Repurchased and Retired During Period, Value	$ (90,057)		$ (90,057)
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures			1,556,953
Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures	45,537		$ 45,537
Dividends on preferred stock	(47,982)			(47,982)
Dividends on common stock	(57,677)			(57,677)
Increase (Decrease) in Deferred Compensation	1,029			1,029
Balance at Dec. 31, 2016	$ 7,634,306	$ 709,601	$ 4,724,715	$ 2,321,571	$ (121,581)
Balance (in shares) at Dec. 31, 2016	203,085,100		203,085,100