Medium- And Long-Term Debt (Schedule Of Medium- And Long-Term Debt) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended		12 Months Ended
	Jun. 30, 2014		Dec. 31, 2013
Debt Instruments [Line Items]
Total medium- and long-term debt	$ 2,620		$ 3,543
Parent Company
Debt Instruments [Line Items]
Total medium- and long-term debt	960		617
Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	1,638		1,898
Total medium- and long-term debt	1,660		2,926
4.80% subordinated notes due 2015 | Parent Company
Debt Instruments [Line Items]
Subordinated notes	311	[1]	318	[1]
Stated interest rate	4.80%		4.80%
Maturity Date	May 01, 2015		May 01, 2015
3.00% notes due 2015 | Parent Company
Debt Instruments [Line Items]
Medium-term notes	300		299
Stated interest rate	3.00%		3.00%
Maturity Date	Sep. 16, 2015		Sep. 16, 2015
2.125% notes due 2019 | Parent Company
Debt Instruments [Line Items]
Medium-term notes	349	[1]	0	[1]
Stated interest rate	2.125%
Maturity Date	May 23, 2019
5.70% subordinated notes due 2014 | Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	0	[1]	255	[1]
Stated interest rate			5.70%
Maturity Date			Jun. 01, 2014
8.375% subordinated notes due 2014 | Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	182		183
Stated interest rate	8.375%		8.375%
Maturity Date	Jul. 15, 2014		Jul. 15, 2024
Earliest call date	Jul. 15, 2014		Jul. 15, 2014
5.75% subordinated notes due 2016 | Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	676	[1]	681	[1]
Stated interest rate	5.75%		5.75%
Maturity Date	Nov. 21, 2016		Nov. 21, 2016
5.20% subordinated notes due 2017 | Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	559	[1]	566	[1]
Stated interest rate	5.20%		5.20%
Maturity Date	Aug. 22, 2017		Aug. 22, 2017
7.875% subordinated notes due 2026 | Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	221	[1]	213	[1]
Stated interest rate	7.875%		7.875%
Maturity Date	Sep. 15, 2026		Sep. 15, 2026
Federal Home Loan Bank advances floating-rate based on LIBOR indices due 2014 | Subsidiaries
Debt Instruments [Line Items]
Federal Home Loan Bank advances	0		1,000
Maturity Date			May 07, 2014
6.0% - 6.4% fixed-rate notes due 2020 | Subsidiaries
Debt Instruments [Line Items]
Other Notes	$ 22		$ 28
Fixed Interest Rate - minimum	6.00%		6.00%
Fixed Interest Rate - maximum	6.40%		6.40%
Maturity Date	Jun. 30, 2020		Jun. 30, 2020

[1] The carrying value of medium- and long-term debt has been adjusted to reflect the gain attributable to the risk hedged with interest rate swaps.