Investment Securities (Schedule of Available-for-sale Securities Reconciliation) (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 16,107,000,000	$ 17,425,000,000
Available-for-sale Securities, Gross Unrealized Gains	213,000,000	166,000,000
Available-for-sale Securities, Gross Unrealized Losses	(183,000,000)	(508,000,000)
Available-for-sale Securities	16,137,000,000us-gaap_AvailableForSaleSecurities	17,083,000,000us-gaap_AvailableForSaleSecurities
Total agency backed bonds	7,557,000,000	8,266,000,000
Deposit Assets	15,000,000us-gaap_DepositAssets	15,000,000us-gaap_DepositAssets
Cash Equivalents, at Carrying Value	2,000,000,000us-gaap_CashEquivalentsAtCarryingValue	2,400,000,000us-gaap_CashEquivalentsAtCarryingValue
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	15,216,000,000	16,527,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	164,000,000	92,000,000
Available-for-sale Debt Securities, Gross Unrealized Loss	(149,000,000)	(480,000,000)
Available-for-sale Securities, Debt Securities	15,231,000,000	16,139,000,000
US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	1,195,000,000	1,495,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	1,000,000	1,000,000
Available-for-sale Debt Securities, Gross Unrealized Loss	(18,000,000)	(69,000,000)
Available-for-sale Securities, Debt Securities	1,178,000,000	1,427,000,000
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	389,000,000	316,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	17,000,000	0
Available-for-sale Debt Securities, Gross Unrealized Loss	0	(1,000,000)
Available-for-sale Securities, Debt Securities	406,000,000	315,000,000
Foreign Government Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	224,000,000	287,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	8,000,000	4,000,000
Available-for-sale Debt Securities, Gross Unrealized Loss	0	(3,000,000)
Available-for-sale Securities, Debt Securities	232,000,000	288,000,000
Residential Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	10,431,000,000	11,131,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	119,000,000	49,000,000
Available-for-sale Debt Securities, Gross Unrealized Loss	(125,000,000)	(398,000,000)
Available-for-sale Securities, Debt Securities	10,425,000,000	10,782,000,000
Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	254,000,000	39,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	0	0
Available-for-sale Debt Securities, Gross Unrealized Loss	(1,000,000)	0
Available-for-sale Securities, Debt Securities	253,000,000	39,000,000
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	1,989,000,000	2,207,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	5,000,000	15,000,000
Available-for-sale Debt Securities, Gross Unrealized Loss	(3,000,000)	(3,000,000)
Available-for-sale Securities, Debt Securities	1,991,000,000	2,219,000,000
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	734,000,000	1,052,000,000
Available-for-sale Debt Securities Gross Unrealized Gain	14,000,000	23,000,000
Available-for-sale Debt Securities, Gross Unrealized Loss	(2,000,000)	(6,000,000)
Available-for-sale Securities, Debt Securities	746,000,000	1,069,000,000
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Equity Securities, Amortized Cost Basis	891,000,000	898,000,000
Available-for-sale Equity Securities, Gross Unrealized Gain	49,000,000	74,000,000
Available-for-sale Equity Securities, Gross Unrealized Loss	(34,000,000)	(28,000,000)
Available-for-sale Securities, Equity Securities	$ 906,000,000	$ 944,000,000

Total agency backed bonds, available for sale.

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