Fair Value (Fair Value Option - Summary Of Changes Included In The Condensed Consolidated Statement Of Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		$ 406	$ 344	$ 776
Mortgage Loans Held-For-Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	51	431	338	794
Fair Value, Option, Credit Risk, Gains (Losses) on Assets	0	0	0	0
Mortgage Loans Held-For-Sale [Member] | Interest and fees on finance receivables and loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	0	0	0	0
Mortgage Loans Held-For-Sale [Member] | Interest on loans held-for-sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	18	49	58	128
Mortgage Loans Held-For-Sale [Member] | Interest on long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	0	0	0	0
Mortgage Loans Held-For-Sale [Member] | Gain on mortgage loans, net [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	33	382	280	666
Mortgage Loans Held-For-Sale [Member] | Other Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	0	0	0	0
Consumer Mortgage Finance Receivables And Loans, Net [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		57	121	231
Fair Value, Option, Credit Risk, Gains (Losses) on Assets		(54)	(24)	(49)
Consumer Mortgage Finance Receivables And Loans, Net [Member] | Interest and fees on finance receivables and loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		48	59	154
Consumer Mortgage Finance Receivables And Loans, Net [Member] | Interest on loans held-for-sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		0	0	0
Consumer Mortgage Finance Receivables And Loans, Net [Member] | Interest on long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		0	0	0
Consumer Mortgage Finance Receivables And Loans, Net [Member] | Gain on mortgage loans, net [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		0	0	0
Consumer Mortgage Finance Receivables And Loans, Net [Member] | Other Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		9	62	77
On-Balance Sheet Securitization Debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		(83)	(115)	(250)
Fair Value, Option, Credit Risk, Gains (Losses) on Liabilities		37	(8)	14
On-Balance Sheet Securitization Debt [Member] | Interest and fees on finance receivables and loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		0	0	0
On-Balance Sheet Securitization Debt [Member] | Interest on loans held-for-sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		0	0	0
On-Balance Sheet Securitization Debt [Member] | Interest on long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		(29)	(34)	(89)
On-Balance Sheet Securitization Debt [Member] | Gain on mortgage loans, net [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		0	0	0
On-Balance Sheet Securitization Debt [Member] | Other Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		(54)	(81)	(161)
Loan repurchase liabilities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		1		1
Fair Value, Option, Credit Risk, Gains (Losses) on Liabilities		0		0
Loan repurchase liabilities [Member] | Interest and fees on finance receivables and loans [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		0		0
Loan repurchase liabilities [Member] | Interest on loans held-for-sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		0		0
Loan repurchase liabilities [Member] | Interest on long-term debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		0		0
Loan repurchase liabilities [Member] | Gain on mortgage loans, net [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		0		0
Loan repurchase liabilities [Member] | Other Income [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)		$ 1		$ 1