Shareholders' Equity (Narrative) (Details) (USD $)	0 Months Ended		1 Months Ended	12 Months Ended						12 Months Ended		0 Months Ended	12 Months Ended			0 Months Ended	12 Months Ended		12 Months Ended		12 Months Ended					12 Months Ended
	Sep. 16, 2013	Jun. 03, 2013	Jun. 30, 2009	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	May 03, 2013	Dec. 05, 2012	Dec. 31, 2013 Series A Preferred Stock [Member]	Dec. 31, 2012 Series A Preferred Stock [Member]	Sep. 16, 2013 Series C Preferred Stock [Member]	Dec. 31, 2013 Series C Preferred Stock [Member]	Dec. 31, 2012 Series C Preferred Stock [Member]	Dec. 31, 2013 Series D Preferred Stock [Member]	Jun. 15, 2012 Series E Preferred Stock [Member]	Dec. 31, 2013 Series F Preferred Stock [Member]	Dec. 31, 2012 Series F Preferred Stock [Member]	Dec. 31, 2013 Series G Preferred Stock [Member]	Dec. 31, 2012 Series G Preferred Stock [Member]	Dec. 31, 2013 Preferred Stock [Member]	Dec. 31, 2012 Preferred Stock [Member]	Dec. 31, 2013 Retained Earnings [Member]	Dec. 31, 2012 Retained Earnings [Member]	Dec. 05, 2012 Warrant [Member]	Dec. 31, 2013 Common Stock [Member]	Dec. 31, 2012 Common Stock [Member]	Dec. 31, 2011 Common Stock [Member]
Schedule of Equity Method Investments [Line Items]
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax				$ 144,343,000	$ 93,213,000
Liquidation preference of preferred stock (per share)				$ 1,000				$ 25
Preferred stock, authorized shares				4,400,000	4,400,000					140,000,000							250,000,000		200,000,000
Variable dividend payment rate										> of 4.0% or 3mL+0.52%
Carrying value, Preferred stock				1,003,970,000	1,128,302,000					66,127,000	60,220,000		0	924,332,000			143,750,000	143,750,000	171,827,000	0
Price per share									$ 36.27
Fees And Commissions For Sale Of Preferred Stock																3,800,000
Preferred Stock, Dividend Rate, Percentage													9.50%				7.90%		6.30%
Debt Instrument, Redemption Price, Percentage												100.00%
Beneficial conversion feature of modified subordinated debt recorded in common stock			203,000,000	206,000	15,232,000	43,139,000																				76,400,000
Preferred stock redemption								285,000,000							1,400,000,000
Stock Issued During Period, Value, New Issues				784,318,000	141,342,000	25,500,000															800,000,000	143,750,000				(15,682,000)	(2,408,000)	25,048,000
Stock Issued During Period, Shares, New Issues						1,100,000																						1,067,540
Preferred Stock, Accretion of Redemption Discount				44,700,000	21,600,000
Common stock warrants issued to the U.S. Treasury																									5,789,909
Average price of common stock (per share)						$ 23.89
Common stock value, net of commissions and fees						25,000,000
Warrants sold							29,300,000
Common stock issued for preferred stock redemption				799,468,000	(1,542,500,000)							800,000,000				143,000,000					925,748,000	(1,542,500,000)	(125,700,000)	(3,830,000)		(580,000)	3,830,000
Stock Redeemed or Called During Period, Shares	799,467
Share Price				$ 36.63
Total invested assets of trusts				83,700,000	72,200,000
Total obligations of trusts				98,700,000	87,200,000
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax				(861,000)	(5,063,000)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax				16,625,000	2,870,000
Preferred stock, liquidation preference per depositary share				$ 25
Ownership percentage of depositary shares				2.50%
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders		4,800,000
Common Stock Held in Trust				$ 15,000,000	$ 15,000,000