Derivative Instruments - Credit Derivatives (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Total credit derivatives and credit-related notes
Protection sold	$ (666,865)	$ (738,464)
Protection purchased with identical underlyings	685,556	749,766
Net protection (sold)/purchased	18,691	11,302
Other protection purchased	21,430	20,966
Total credit derivatives
Total credit derivatives and credit-related notes
Protection sold	(666,865)	(738,464)
Protection purchased with identical underlyings	685,556	749,766
Net protection (sold)/purchased	18,691	11,302
Other protection purchased	12,133	12,541
Credit default swaps
Total credit derivatives and credit-related notes
Protection sold	(610,946)	(697,220)
Protection purchased with identical underlyings	623,709	707,282
Net protection (sold)/purchased	12,763	10,062
Other protection purchased	3,630	4,053
Other credit derivatives
Total credit derivatives and credit-related notes
Protection sold	(55,919)	(41,244)
Protection purchased with identical underlyings	61,847	42,484
Net protection (sold)/purchased	5,928	1,240
Other protection purchased	8,503	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	$ 9,297	$ 8,425