Debt And Shareholders' Equity (Narrative) (Details) (USD $)	0 Months Ended					3 Months Ended			9 Months Ended									9 Months Ended	0 Months Ended		9 Months Ended	0 Months Ended					0 Months Ended		0 Months Ended			3 Months Ended	9 Months Ended			3 Months Ended			9 Months Ended		0 Months Ended
	Oct. 31, 2013	Sep. 16, 2013	Sep. 12, 2013	Jun. 13, 2013	Jun. 03, 2013	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2009	Sep. 30, 2013	Sep. 30, 2012	Sep. 15, 2023	Nov. 15, 2018	Nov. 06, 2013	Jun. 18, 2013	May 03, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2013 Preferred Stock [Member]	Sep. 16, 2013 Series C Preferred Stock [Member]	May 06, 2013 Series C Preferred Stock [Member]	Sep. 30, 2013 Series C Preferred Stock [Member]	Jun. 15, 2023 Series I Preferred Stock [Member]	May 17, 2013 Series I Preferred Stock [Member]	Mar. 15, 2023 Series F Preferred Stock [Member]	Feb. 07, 2013 Series F Preferred Stock [Member]	Feb. 07, 2013 Series G Preferred Stock [Member]	May 03, 2013 Series H Preferred Stock [Member]	Aug. 02, 2013 Series A Preferred Stock [Member]	Sep. 15, 2023 Series J Preferred Stock [Member]	Aug. 11, 2013 Series J Preferred Stock [Member]	Aug. 07, 2013 Series J Preferred Stock [Member]	Sep. 30, 2013 Long-Term Senior Notes [Member]	Sep. 30, 2013 Long-Term Senior Notes [Member]	Sep. 30, 2013 Minimum [Member]	Sep. 30, 2013 Maximum [Member]	Sep. 30, 2013 Short-Term Senior [Member]	Jun. 13, 2013 $300 Million Senior Long-Term Note [Member]	Jun. 13, 2013 $500 Million Senior Long-Term Note [Member]	Sep. 30, 2013 $500 Million Senior Long-Term Note [Member]	Jun. 18, 2013 $500 Million Senior Long-Term Note [Member]	Aug. 02, 2013 LIBOR Plus Zero Point Five Two [Member] Series A Preferred Stock [Member]	Aug. 02, 2013 Four Percent [Member] Series A Preferred Stock [Member]	Nov. 06, 2013 Maximum [Member]	Nov. 06, 2013 Minimum [Member]
Debt And Shareholders' Equity [Line Items]
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests					$ 4,800,000
Stock Redeemed or Called During Period, Value										(1,542,500,000)									800,000,000	926,000,000
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax									49,228,000	56,748,000
Allowance for loan losses transfered from commerical loans to commercial real estate loans from modified reporting							83,100,000			83,100,000						83,000,000	68,200,000
Trust Preferred Securities Rate, Redeemed															8.00%
Trust Preferred Securities, Shares Redeemed															11,400,000
Preferred Stock, Liquidation Preference, Value															1.00
Preferred Stock, Liquidation Preference Per Share															$ 25
Debt [Abstract]
Cumulative perpetual preferred stock value, issued						1,003,970,000			1,003,970,000							1,128,302,000							301,000,000					6,000,000			195,000,000
Repayments of notes																																18,000,000				5,000,000
Dividends on common stock, per share									$ 0.09	$ 0.03
Debt issuance amount during period																																29,000,000	97,000,000
Interest rate on senior notes	5.70%		7.00%								3.90%	4.20%																						2.55%	5.50%		4.50%	7.75%					6.00%	5.50%
Debt Instrument, Maturity Date									Nov. 01, 2019																														Sep. 23, 2014
Proceeds from Issuance of Long-term Debt	160,000,000		86,000,000			116,461,000	49,082,000		484,408,000	648,468,000
Proceeds from Issuance of Senior Long-term Debt				297,200,000
Gains (Losses) on Extinguishment of Debt						0	0		40,282,000	0
Gains (Losses) on Extinguishment of Debt, before Write off of Deferred Debt Issuance Cost									22,900,000
Write off of Deferred Debt Issuance Cost									17,400,000
Document Fiscal Year Focus						2013			2013
Debt Issuance Cost	162,000,000		88,000,000																																		300,000,000
Stockholders' Equity [Abstract]
Convertible subordinated debt converted into depositary shares																		1,200,000
Convertible preferred stock, shares issued upon conversion																					1,210
Common stock outstanding under conversion feature						77,000,000			77,000,000
Convertible subordinated debt, at par						457,000,000			457,000,000
Debt discount						113,000,000			113,000,000
Stock Issued During Period, Value, New Issues									800,000,000	141,342,000
Issuance of preferred stock									784,373,000																172,000,000		126,000,000
Preferred Stock, Shares Issued																							300,893			171,827	126,221	5,907			195,152
Preferred Stock, Par or Stated Value Per Share																															$ 1,000
Preferred stock, dividend rate																			9.50%			3.80%	5.80%	4.24%	6.30%		5.75%		4.44%	7.20%											0.52%	4.00%
Stock Redeemed or Called During Period, Shares		799,467
Preferred Stock, Redemption Price Per Share																			$ 25
Preferred Stock, Value, Outstanding																					126,000,000
Debt Instrument, Convertible, Beneficial Conversion Feature						0	917,000	203,000,000	206,000	14,519,000
Preferred stock redemption value, net															285,000,000
Debt Instrument, Repurchased Face Amount														258,000,000
Senior Notes																																								500,000,000
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax									12,426,000	598,000
Par Amount of Convertible and Nonconvertible Subordinated Notes Offered to Purchase													$ 250,000,000