Variable Interest Entities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Assets And Liabilities Of Consolidated VIEs [Line Items]
Principal Amount Of GICs Redeemed	$ 386		$ 1,981						$ 386
Total revenues of consolidated VIEs	11,770	11,369	11,458	11,442	11,577	12,015	12,440	13,036	46,039	49,068	49,856
Provision for Loan and Lease Losses									3,891	3,951	7,085
Commingled Cash Amounts Owed To Consolidated Securitization Entities	6,225				5,655				6,225	5,655
Commingled cash receivable from CSEs	6,143				5,165				6,143	5,165
Loans and Finance Receivables [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	40,916				37,860				40,916	37,860
Investment Securities [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	4,486				5,320				4,486	5,320
Assets Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	2,479				3,149				2,479	3,149
Assets, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	47,881				46,329				47,881	46,329
Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	707				848				707	848
Nonrecourse Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	29,123				28,758				29,123	28,758
Liabilities Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	3,136				5,847				3,136	5,847
Liabilities, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	32,966				35,453				32,966	35,453
Consolidated Variable Interest Entities [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Total revenues of consolidated VIEs									6,638	6,162	6,914
Provision for Loan and Lease Losses									1,171	1,146	1,596
Interest And Other Financial Charges									541	593	765
Industrial Equipment Joint Venture [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	1,438								1,438
Liabilities VIE	836								836
Power Generating And Leasing [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	891								891
Liabilities VIE	0								0
Insurance Entities [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	1,193								1,193
Liabilities VIE	588								588
Trinity [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Intercompany Advances Eliminated In Consolidation	2,441				1,006				2,441	1,006
Trinity [Member] | Loans and Finance Receivables [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	0				0				0	0
Trinity [Member] | Investment Securities [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	3,435				4,289				3,435	4,289
Trinity [Member] | Assets Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	217				389				217	389
Trinity [Member] | Assets, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	3,652				4,678				3,652	4,678
Trinity [Member] | Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	0				0				0	0
Trinity [Member] | Nonrecourse Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	0				0				0	0
Trinity [Member] | Liabilities Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	1,656				4,456				1,656	4,456
Trinity [Member] | Liabilities, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	1,656				4,456				1,656	4,456
Other Items [Member] | Loans and Finance Receivables [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	1,902				2,973				1,902	2,973
Other Items [Member] | Investment Securities [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	1,051				1,031				1,051	1,031
Other Items [Member] | Assets Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	1,873				2,250				1,873	2,250
Other Items [Member] | Assets, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	4,826				6,254				4,826	6,254
Other Items [Member] | Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	707				821				707	821
Other Items [Member] | Nonrecourse Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	0				980				0	980
Other Items [Member] | Liabilities Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	1,313				1,312				1,313	1,312
Other Items [Member] | Liabilities, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	2,020				3,113				2,020	3,113
Credit Card Receivable [Member] | Consolidated Securitization Entities [Member] | Loans and Finance Receivables [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	24,169				19,229				24,169	19,229
Credit Card Receivable [Member] | Consolidated Securitization Entities [Member] | Investment Securities [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	0				0				0	0
Credit Card Receivable [Member] | Consolidated Securitization Entities [Member] | Assets Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	29				17				29	17
Credit Card Receivable [Member] | Consolidated Securitization Entities [Member] | Assets, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	24,198				19,246				24,198	19,246
Credit Card Receivable [Member] | Consolidated Securitization Entities [Member] | Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	0				0				0	0
Credit Card Receivable [Member] | Consolidated Securitization Entities [Member] | Nonrecourse Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	17,208				14,184				17,208	14,184
Credit Card Receivable [Member] | Consolidated Securitization Entities [Member] | Liabilities Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	146				37				146	37
Credit Card Receivable [Member] | Consolidated Securitization Entities [Member] | Liabilities, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	17,354				14,221				17,354	14,221
Equipment [Member] | Consolidated Securitization Entities [Member] | Loans and Finance Receivables [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	12,456				10,523				12,456	10,523
Equipment [Member] | Consolidated Securitization Entities [Member] | Investment Securities [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	0				0				0	0
Equipment [Member] | Consolidated Securitization Entities [Member] | Assets Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	360				283				360	283
Equipment [Member] | Consolidated Securitization Entities [Member] | Assets, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	12,816				10,806				12,816	10,806
Equipment [Member] | Consolidated Securitization Entities [Member] | Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	0				2				0	2
Equipment [Member] | Consolidated Securitization Entities [Member] | Nonrecourse Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	9,811				8,166				9,811	8,166
Equipment [Member] | Consolidated Securitization Entities [Member] | Liabilities Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	11				0				11	0
Equipment [Member] | Consolidated Securitization Entities [Member] | Liabilities, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	9,822				8,168				9,822	8,168
Commercial Real Estate [Member] | Consolidated Securitization Entities [Member] | Loans and Finance Receivables [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	50				3,521				50	3,521
Commercial Real Estate [Member] | Consolidated Securitization Entities [Member] | Investment Securities [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	0				0				0	0
Commercial Real Estate [Member] | Consolidated Securitization Entities [Member] | Assets Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	0				210				0	210
Commercial Real Estate [Member] | Consolidated Securitization Entities [Member] | Assets, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	50				3,731				50	3,731
Commercial Real Estate [Member] | Consolidated Securitization Entities [Member] | Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	0				25				0	25
Commercial Real Estate [Member] | Consolidated Securitization Entities [Member] | Nonrecourse Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	54				3,659				54	3,659
Commercial Real Estate [Member] | Consolidated Securitization Entities [Member] | Liabilities Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	2				19				2	19
Commercial Real Estate [Member] | Consolidated Securitization Entities [Member] | Liabilities, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	56				3,703				56	3,703
Trade Accounts Receivable [Member] | Consolidated Securitization Entities [Member] | Loans and Finance Receivables [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	2,339				1,614				2,339	1,614
Trade Accounts Receivable [Member] | Consolidated Securitization Entities [Member] | Investment Securities [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	0				0				0	0
Trade Accounts Receivable [Member] | Consolidated Securitization Entities [Member] | Assets Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	0				0				0	0
Trade Accounts Receivable [Member] | Consolidated Securitization Entities [Member] | Assets, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Assets VIE	2,339				1,614				2,339	1,614
Trade Accounts Receivable [Member] | Consolidated Securitization Entities [Member] | Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	0				0				0	0
Trade Accounts Receivable [Member] | Consolidated Securitization Entities [Member] | Nonrecourse Borrowings [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	2,050				1,769				2,050	1,769
Trade Accounts Receivable [Member] | Consolidated Securitization Entities [Member] | Liabilities Other [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	8				23				8	23
Trade Accounts Receivable [Member] | Consolidated Securitization Entities [Member] | Liabilities, Total [Member]
Assets And Liabilities Of Consolidated VIEs [Line Items]
Liabilities VIE	$ 2,058				$ 1,792				$ 2,058	$ 1,792