Shareholders' Equity (Narrative) (Details) (USD $)	0 Months Ended			1 Months Ended	12 Months Ended				0 Months Ended
	Jul. 29, 2014	Sep. 16, 2013	Jun. 03, 2013	Jun. 30, 2009	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010	Jun. 15, 2012	Jul. 28, 2014	Dec. 05, 2012
Schedule of Equity Method Investments [Line Items]
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax					$ 60,795,000	$ 147,133,000
Liquidation preference of preferred stock (per share)					$ 1,000
Preferred stock, authorized shares					4,400,000	4,400,000
Carrying value, Preferred stock					1,004,011,000	1,003,970,000
Price per share											$ 36.27
Common Stock					4,723,855,000	4,179,024,000				525,000,000
Common Stock, Shares, Issued					203,014,903	184,677,696				17,600,000
Common Stock, Par or Stated Value Per Share										$ 29.80
Company Capital Plan, issuance of new common equity	400,000,000
Beneficial conversion feature of modified subordinated debt recorded in common stock				203,000,000		206,000	15,232,000
Preferred Stock, Accretion of Redemption Discount						44,700,000
Common stock value, net of commissions and fees	516,000,000
Warrants sold								29,300,000
Common stock issued for preferred stock redemption						(799,468,000)	(1,542,500,000)
Stock Redeemed or Called During Period, Shares		799,467
Total invested assets of trusts					86,600,000	83,700,000
Total obligations of trusts					100,900,000	98,700,000
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax					467,000	(3,651,000)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax					(8,764,000)	16,625,000
Preferred stock, liquidation preference per depositary share					$ 25
IncreaseInCarryingValueOfPreferredStock					5,900,000
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders			4,800,000
Common Stock Held in Trust					14,300,000	15,000,000
Warrant Exercise Price					$ 36.36
Series A Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Preferred stock, authorized shares					140,000,000
Variable dividend payment rate					> of 4.0% or 3mL+0.52%
Carrying value, Preferred stock					66,168,000	66,127,000
Series C Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Preferred Stock, Dividend Rate, Percentage					9.50%
Debt Instrument, Redemption Price, Percentage		100.00%
Common stock issued for preferred stock redemption		800,000,000
Series D Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Preferred stock redemption					1,400,000,000
Series E Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Fees And Commissions For Sale Of Preferred Stock									3,800,000
Common stock issued for preferred stock redemption									143,000,000
Series F Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Preferred stock, authorized shares					250,000,000
Carrying value, Preferred stock					143,750,000	143,750,000
Preferred Stock, Dividend Rate, Percentage					7.90%
Series G Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Preferred stock, authorized shares					200,000,000
Carrying value, Preferred stock					171,827,000	171,827,000
Preferred Stock, Dividend Rate, Percentage					6.30%
Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Common stock issued for preferred stock redemption						(925,748,000)	(1,542,500,000)
Retained Earnings [Member]
Schedule of Equity Method Investments [Line Items]
Common stock issued for preferred stock redemption						125,700,000	(3,830,000)
Warrant [Member]
Schedule of Equity Method Investments [Line Items]
Common stock warrants issued to the U.S. Treasury											5,789,909
Common Stock [Member]
Schedule of Equity Method Investments [Line Items]
Beneficial conversion feature of modified subordinated debt recorded in common stock					76,400,000
Common stock issued for preferred stock redemption						$ 580,000	$ 3,830,000