Shareholders' Equity (Summary Of Preferred Stock) (Details) (USD $)	0 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Common Stock Held in Trust	$ 15,000,000	$ 15,000,000	$ 15,000,000
Preferred stock, authorized shares	4,400,000	4,400,000	4,400,000
Carrying value, Preferred stock	1,003,970,000	1,003,970,000	1,128,302,000
Series A Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Rate		> of 4.0% or 3mL+0.52%
Earliest redemption date		Dec. 15, 2011
Preferred stock, authorized shares	140,000,000	140,000,000
Outstanding Shares at December 31, 2012	66,000,000	66,000,000
Carrying value, Preferred stock	66,127,000	66,127,000	60,220,000
Series C Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Carrying value, Preferred stock	0	0	924,332,000
Preferred Stock, Dividend Rate, Percentage		9.50%
Series F Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Earliest redemption date		Jun. 15, 2017
Preferred stock, authorized shares	250,000,000	250,000,000
Outstanding Shares at December 31, 2012	143,750,000	143,750,000
Carrying value, Preferred stock	143,750,000	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]
Interest rate following earliest redemption date	3mL+4.24%
Earliest redemption date		Mar. 15, 2023
Preferred stock, authorized shares	200,000,000	200,000,000
Outstanding Shares at December 31, 2012	171,827,000	171,827,000
Carrying value, Preferred stock	171,827,000	171,827,000	0
Preferred Stock, Dividend Rate, Percentage		6.30%
Series H Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Earliest redemption date		Jun. 15, 2019
Preferred stock, authorized shares	126,221,000	126,221,000
Outstanding Shares at December 31, 2012	126,221,000	126,221,000
Carrying value, Preferred stock	126,221,000	126,221,000	0
Preferred Stock, Dividend Rate, Percentage		5.75%
Series I Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Interest rate following earliest redemption date	3mL+3.80%
Earliest redemption date		Jun. 15, 2023
Preferred stock, authorized shares	300,893,000	300,893,000
Outstanding Shares at December 31, 2012	300,893,000	300,893,000
Carrying value, Preferred stock	300,893,000	300,893,000	0
Preferred Stock, Dividend Rate, Percentage		5.80%
Series J Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Interest rate following earliest redemption date	3mL+4.44%
Earliest redemption date		Sep. 15, 2023
Preferred stock, authorized shares	195,152,000	195,152,000
Outstanding Shares at December 31, 2012	195,152,000	195,152,000
Carrying value, Preferred stock	$ 195,152,000	$ 195,152,000	$ 0
Preferred Stock, Dividend Rate, Percentage		7.20%