Condensed Consolidated Statements of Shareholder's Equity (Unaudited) - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Surplus	Accumulated Deficit	Accumulated Other Comprehensive Loss	Non-controlling Interests
Balance, beginning of period at Dec. 31, 2014	$ 12,003,574		$ 2,230	$ 15,285,991	$ (3,262,181)	$ (51,357)	$ 28,891
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	141,767				141,110		657
Other comprehensive income, net of tax	23,703					23,703
Vesting of restricted stock	(7,662)			(7,662)
Amortization of stock-based deferred compensation	548			548
Balance, end of period at Mar. 31, 2015	12,161,930		2,230	15,278,877	(3,121,071)	(27,654)	29,548
Balance, beginning of period at Dec. 31, 2015	12,577,284	$ 229,475	2,230	15,188,474	(2,772,614)	(99,307)	29,026
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	34,478				33,950		528
Other comprehensive income, net of tax	67,361					67,361
Preferred stock dividends	(3,219)			(3,219)
Vesting of restricted stock	(6,175)			(6,175)
Amortization of stock-based deferred compensation	1,204			1,204
Balance, end of period at Mar. 31, 2016	$ 12,670,933	$ 229,475	$ 2,230	$ 15,180,284	$ (2,738,664)	$ (31,946)	$ 29,554