Investment Securities (Schedule of Available-for-sale Securities Reconciliation) (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 13,997,000,000	$ 15,167,000,000
Available-for-sale Securities, Gross Unrealized Gains	262,000,000	197,000,000
Available-for-sale Securities, Gross Unrealized Losses	(81,000,000)	(229,000,000)
Available-for-sale Securities	14,178,000,000	15,135,000,000
Total agency backed bonds	4,983,000,000	6,114,000,000
Deposit Assets	15,000,000	16,000,000
Cash Equivalents, at Carrying Value	3,400,000,000	5,600,000,000
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	12,804,000,000	13,979,000,000
Available-for-sale Securities, Gross Unrealized Gains	230,000,000	172,000,000
Available-for-sale Securities, Gross Unrealized Losses	(8,000,000)	(75,000,000)
Available-for-sale Securities	13,026,000,000	14,076,000,000
US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	2,212,000,000	1,535,000,000
Available-for-sale Securities, Gross Unrealized Gains	3,000,000	13,000,000
Available-for-sale Securities, Gross Unrealized Losses	(1,000,000)	(2,000,000)
Available-for-sale Securities	2,214,000,000	1,546,000,000
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	0	1,000,000
Available-for-sale Securities, Gross Unrealized Gains	0	0
Available-for-sale Securities, Gross Unrealized Losses	0	0
Available-for-sale Securities	0	1,000,000
Foreign Government Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	295,000,000	765,000,000
Available-for-sale Securities, Gross Unrealized Gains	8,000,000	20,000,000
Available-for-sale Securities, Gross Unrealized Losses	0	(1,000,000)
Available-for-sale Securities	303,000,000	784,000,000
Residential Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	6,779,000,000	7,266,000,000
Available-for-sale Securities, Gross Unrealized Gains	130,000,000	87,000,000
Available-for-sale Securities, Gross Unrealized Losses	(3,000,000)	(41,000,000)
Available-for-sale Securities	6,906,000,000	7,312,000,000
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	2,309,000,000	2,600,000,000
Available-for-sale Securities, Gross Unrealized Gains	32,000,000	28,000,000
Available-for-sale Securities, Gross Unrealized Losses	(1,000,000)	(13,000,000)
Available-for-sale Securities	2,340,000,000	2,615,000,000
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	1,209,000,000	1,486,000,000
Available-for-sale Securities, Gross Unrealized Gains	57,000,000	23,000,000
Available-for-sale Securities, Gross Unrealized Losses	(3,000,000)	(18,000,000)
Available-for-sale Securities	1,263,000,000	1,491,000,000
Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	0	326,000,000
Available-for-sale Securities, Gross Unrealized Gains	0	1,000,000
Available-for-sale Securities, Gross Unrealized Losses	0	0
Available-for-sale Securities	0	327,000,000
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	1,193,000,000	1,188,000,000
Available-for-sale Securities, Gross Unrealized Gains	32,000,000	25,000,000
Available-for-sale Securities, Gross Unrealized Losses	(73,000,000)	(154,000,000)
Available-for-sale Securities	$ 1,152,000,000	$ 1,059,000,000

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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-Publisher FASB

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+ Details

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

- Definition

Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References+ Details