Loans - Purchased, Sold and Reclassified to Held-for-Sale (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Retained Loans Purchases Sales and Transfer Into Held For Sale By Portfolio Segment [Line Items]
Purchases	$ 7,433	$ 8,319	$ 8,641
Sales	14,287	14,036	9,077
Retained loans reclassified to held-for-sale	2,235	4,810	7,211
Consumer, excluding credit card
Retained Loans Purchases Sales and Transfer Into Held For Sale By Portfolio Segment [Line Items]
Purchases	5,279	7,434	7,616
Sales	5,099	6,655	4,845
Retained loans reclassified to held-for-sale	1,514	1,190	1,261
Excluded retained loans purchased from correspondents that were originated in accordance with the Firm's underwriting standards	50,300	15,100	5,700
Credit card
Retained Loans Purchases Sales and Transfer Into Held For Sale By Portfolio Segment [Line Items]
Purchases	0	0	328
Sales	0	0	0
Retained loans reclassified to held-for-sale	79	3,039	309
Wholesale
Retained Loans Purchases Sales and Transfer Into Held For Sale By Portfolio Segment [Line Items]
Purchases	2,154	885	697
Sales	9,188	7,381	4,232
Retained loans reclassified to held-for-sale	$ 642	$ 581	$ 5,641