Allowance for Loan and Lease Losses - Summary of Changes in Allowance for Loan and Lease Losses (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				$ 4,383					$ 4,383
Provision for Loan, lease and Other losses	$ 1,380	$ 1,092	$ 1,129	935	$ 1,109	$ 993	$ 704	$ 735	4,536	$ 3,541	$ 3,453
Balance at end of the period	5,130				4,383				5,130	4,383
Total Allowance
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				4,383				4,315	4,383	4,315
Provision for Loan and Lease Losses									4,490	3,515
Charge-offs									(5,193)	(4,996)
Recoveries									1,498	1,582
Net charge-offs									(3,695)	(3,414)
Other changes									(48)	(33)
Balance at end of the period	5,130				4,383				5,130	4,383	4,315
Unfunded Lending Commitments Reserve
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				113				87	113	87
Provision for Loan and Lease Losses									46	26
Other changes									9
Balance at end of the period	168				113				168	113	87
Combined Allowance & Unfunded Reserve
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				4,496					4,496
Balance at end of the period	5,298				4,496				5,298	4,496
Credit Card Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				3,204				3,214	3,204	3,214
Provision for Loan and Lease Losses									3,417	2,750
Charge-offs									(4,028)	(3,963)
Recoveries									1,110	1,235
Net charge-offs									(2,918)	(2,728)
Other changes									(49)	(32)
Balance at end of the period	3,654				3,204				3,654	3,204	3,214
Credit Card Portfolio Segment [Member] | Unfunded Lending Commitments Reserve
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				0				0	0	0
Provision for Loan and Lease Losses									0	0
Other changes									0
Balance at end of the period	0				0				0	0	0
Credit Card Portfolio Segment [Member] | Combined Allowance & Unfunded Reserve
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				3,204					3,204
Balance at end of the period	3,654				3,204				3,654	3,204
Consumer Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				779				752	779	752
Provision for Loan and Lease Losses									819	703
Charge-offs									(1,082)	(989)
Recoveries									351	314
Net charge-offs									(731)	(675)
Other changes									1	(1)
Balance at end of the period	868				779				868	779	752
Consumer Portfolio Segment [Member] | Unfunded Lending Commitments Reserve
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				7				7	7	7
Provision for Loan and Lease Losses									0	0
Other changes									0
Balance at end of the period	7				7				7	7	7
Consumer Portfolio Segment [Member] | Combined Allowance & Unfunded Reserve
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				786					786
Balance at end of the period	875				786				875	786
Commercial Banking
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				395				338	395	338
Provision for Loan and Lease Losses									256	67
Charge-offs									(76)	(34)
Recoveries									29	24
Net charge-offs									(47)	(10)
Other changes									0	0
Balance at end of the period	604				395				604	395	338
Commercial Banking | GE Healthcare [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Provision for Loan, lease and Other losses									49
Commercial Banking | Unfunded Lending Commitments Reserve
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				106				80	106	80
Provision for Loan and Lease Losses									46	26
Other changes									9
Balance at end of the period	161				106				161	106	80
Commercial Banking | Combined Allowance & Unfunded Reserve
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				501					501
Balance at end of the period	765				501				765	501
Other
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				5				11	5	11
Provision for Loan and Lease Losses									(2)	(5)
Charge-offs									(7)	(10)
Recoveries									8	9
Net charge-offs									1	(1)
Other changes									0	0
Balance at end of the period	4				5				4	5	11
Other | Unfunded Lending Commitments Reserve
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				0				$ 0	0	0
Provision for Loan and Lease Losses									0	0
Other changes									0
Balance at end of the period	0				0				0	0	$ 0
Other | Combined Allowance & Unfunded Reserve
Allowance for Loan and Lease Losses [Roll Forward]
Balance as beginning of the period				$ 5					5
Balance at end of the period	$ 4				$ 5				$ 4	$ 5