Debt And Shareholders' Equity (Narrative) (Details) (USD $)	0 Months Ended		3 Months Ended		6 Months Ended							3 Months Ended	6 Months Ended	0 Months Ended		6 Months Ended	0 Months Ended							3 Months Ended	6 Months Ended			3 Months Ended			6 Months Ended		0 Months Ended
	Sep. 16, 2013	Jun. 13, 2013	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Aug. 02, 2013	Jun. 18, 2013	May 03, 2013	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2013 Preferred Stock [Member]	Jun. 30, 2013 Preferred Stock [Member]	Sep. 16, 2013 Series C Preferred Stock [Member]	May 06, 2013 Series C Preferred Stock [Member]	Jun. 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]	May 03, 2013 Series H Preferred Stock [Member]	Aug. 02, 2013 Series A Preferred Stock [Member]	Aug. 07, 2013 Series J Preferred Stock [Member]	Jun. 30, 2013 Long-Term Senior Notes [Member]	Jun. 30, 2013 Long-Term Senior Notes [Member]	Jun. 30, 2013 Minimum [Member]	Jun. 30, 2013 Maximum [Member]	Jun. 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]	Jun. 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]
Debt And Shareholders' Equity [Line Items]
Stock Redeemed or Called During Period, Value						$ (842,500,000)								$ 590,000,000	$ 800,000,000
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax					64,437,000	13,919,000
Allowance for loan losses transfered from commerical loans to commercial real estate loans from modified reporting				75,900,000		75,900,000				83,200,000	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			1,728,659,000		1,728,659,000					1,128,302,000								300,900,000					195,000,000
Repayments of notes																								18,000,000				5,000,000
Dividends on common stock, per share					$ 0.05	$ 0.02
Debt issuance amount during period																								49,000,000	69,000,000
Interest rate on senior notes																										2.75%	3.30%		5.00%	8.00%
Debt Instrument, Maturity Date					May 31, 2018																										Sep. 23, 2014
Proceeds from Issuance of Senior Long-term Debt		297,200,000
Gains (Losses) on Extinguishment of Debt			40,282,000	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
Debt Issuance Cost																													300,000,000
Stockholders' Equity [Abstract]
Convertible subordinated debt converted into depositary shares												0	1,200,000
Convertible preferred stock, shares issued upon conversion																1,210
Value added to preferred stock					1,400,000
Intrinsic value of common stock transferred to preferred stock					200,000
Common stock outstanding under conversion feature			76,400,000		76,400,000
Convertible subordinated debt, at par			456,600,000		456,600,000
Percentage of convertible subordinated debt held by five largest investors			56.90%		56.90%
Debt discount			125,300,000		125,300,000
Stock Issued During Period, Value, New Issues					599,000,000	141,342,000
Issuance of preferred stock					588,000,000															171,800,000	126,200,000	5,100,000
Preferred Stock, Shares Issued							236,279																195,152
Preferred Stock, Par or Stated Value Per Share							$ 21.55																$ 1,000
Preferred stock, dividend rate														9.50%			3.80%	5.80%	4.24%	6.30%	5.75%												0.52%	4.00%
Stock Redeemed or Called During Period, Shares	590,000
Stock Redeemed During Period, Depositary Shares	23,600,000
Preferred Stock, Redemption Price Per Share														$ 25
Preferred Stock, Value, Outstanding																799,500,000
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					$ 7,164,000	$ 2,018,000