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		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ 79	$ 283	$ 293	$ 370
Mortgage Loans Held-For-Sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	77	282	287	363
Fair Value, Option, Credit Risk, Gains (Losses) on Assets	1	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)	14	38	40	79
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)	63	244	247	284
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)	34	101	121	174
Fair Value, Option, Credit Risk, Gains (Losses) on Assets	3	22	(24)	5
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)	15	52	59	106
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	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	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	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)	19	49	62	68
On-Balance Sheet Securitization Debt [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	(32)	(100)	(115)	(167)
Fair Value, Option, Credit Risk, Gains (Losses) on Liabilities	(1)	(50)	(8)	(23)
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	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	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)	(8)	(29)	(34)	(60)
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	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)	$ (24)	$ (71)	$ (81)	$ (107)