Medium- And Long-Term Debt (Schedule Of Medium- And Long-Term Debt) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Debt Instruments [Line Items]
Total medium- and long-term debt	$ 3,543	$ 4,720
Parent Company
Debt Instruments [Line Items]
Total medium- and long-term debt	617	629
Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	1,898	2,058
Total medium- and long-term debt	2,926	4,091
4.80% subordinated notes due 2015 [Member] | Parent Company
Debt Instruments [Line Items]
Subordinated notes	318	330
Fixed Interest Rate	4.80%	4.80%
Maturity Date	May 01, 2015	May 01, 2015
3.00% notes due 2015 [Member] | Parent Company
Debt Instruments [Line Items]
Medium-term notes	299	299
Fixed Interest Rate	3.00%	3.00%
Maturity Date	Sep. 16, 2015	Sep. 16, 2015
7.375% subordinated notes due 2013 [Member] | Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	0	51
Fixed Interest Rate	7.375%	7.375%
Maturity Date	Apr. 15, 2013	Apr. 15, 2013
Floating rate based on LIBOR index subordinated note due 2013 [Member] | Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	0	26
Maturity Date	Sep. 15, 2013	Sep. 15, 2013
5.70% subordinated notes due 2014 [Member] | Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	255	267
Fixed Interest Rate	5.70%	5.70%
Maturity Date	Jun. 01, 2014	Jun. 01, 2014
5.75% subordinated notes due 2016 [Member] | Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	681	694
Fixed Interest Rate	5.75%	5.75%
Maturity Date	Nov. 21, 2016	Nov. 21, 2016
5.20% subordinated notes due 2017 [Member] | Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	566	593
Fixed Interest Rate	5.20%	5.20%
Maturity Date	Aug. 22, 2017	Aug. 22, 2017
8.375% subordinated notes due 2024 [Member] | Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	183	186
Fixed Interest Rate	8.375%	8.375%
Maturity Date	Jul. 15, 2024	Jul. 15, 2024
Debt Instrument, Call Date, Earliest	Jul. 15, 2014	Jul. 15, 2014
7.875% subordinated notes due 2026 [Member] | Subsidiaries
Debt Instruments [Line Items]
Subordinated notes	213	241
Fixed 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 2013 to 2014 [Member] | Subsidiaries
Debt Instruments [Line Items]
Federal Home Loan Bank advances	1,000	2,000
Maturity Date	May 07, 2014
Maturity Date Range - start		May 07, 2013
Maturity Date Range - end		May 07, 2014
6.0% - 6.4% fixed-rate notes due 2020 [Member] | Subsidiaries
Debt Instruments [Line Items]
Other Notes	$ 28	$ 33
Interest Rate Range - minimum	6.00%	6.00%
Interest Rate Range - maximum	6.40%	6.40%
Maturity Date	Jun. 30, 2020	Jun. 30, 2020