Derivative Instruments - Credit Derivatives (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Total credit derivatives and credit-related notes
Protection sold	$ (668,957)	$ (738,464)
Protection purchased with identical underlyings	685,193	749,766
Net protection (sold)/purchased	16,236	11,302
Other protection purchased	20,691	20,966
Total credit derivatives
Total credit derivatives and credit-related notes
Protection sold	(668,957)	(738,464)
Protection purchased with identical underlyings	685,193	749,766
Net protection (sold)/purchased	16,236	11,302
Other protection purchased	12,211	12,541
Credit default swaps
Total credit derivatives and credit-related notes
Protection sold	(637,127)	(697,220)
Protection purchased with identical underlyings	644,885	707,282
Net protection (sold)/purchased	7,758	10,062
Other protection purchased	3,649	4,053
Other credit derivatives
Total credit derivatives and credit-related notes
Protection sold	(31,830)	(41,244)
Protection purchased with identical underlyings	40,308	42,484
Net protection (sold)/purchased	8,478	1,240
Other protection purchased	8,562	8,488
Credit-related notes
Total credit derivatives and credit-related notes
Protection sold	0	0
Protection purchased with identical underlyings	0	0
Net protection (sold)/purchased	0	0
Other protection purchased	$ 8,480	$ 8,425