Derivative Instruments - Credit Derivatives, Protection Sold, Notional and Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Protection sold credit derivatives and credit related notes ratings/maturity profile
Protection sold credit derivatives and credit related notes ratings/maturity profile - less than 1 year	$ (128,558)	$ (125,714)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - from 1-5 years	(404,997)	(404,985)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - more than 5 years	(107,749)	(44,479)
Total notional amount	(641,304)	(575,178)
Fair value of receivables	9,597	9,474
Fair value of payables	(3,069)	(3,377)
Net fair value	6,528	6,097
Investment-grade
Protection sold credit derivatives and credit related notes ratings/maturity profile
Protection sold credit derivatives and credit related notes ratings/maturity profile - less than 1 year	(93,329)	(93,905)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - from 1-5 years	(304,945)	(307,648)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - more than 5 years	(80,813)	(35,326)
Total notional amount	(479,087)	(436,879)
Fair value of receivables	5,746	5,521
Fair value of payables	(651)	(835)
Net fair value	5,095	4,686
Noninvestment-grade
Protection sold credit derivatives and credit related notes ratings/maturity profile
Protection sold credit derivatives and credit related notes ratings/maturity profile - less than 1 year	(35,229)	(31,809)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - from 1-5 years	(100,052)	(97,337)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - more than 5 years	(26,936)	(9,153)
Total notional amount	(162,217)	(138,299)
Fair value of receivables	3,851	3,953
Fair value of payables	(2,418)	(2,542)
Net fair value	$ 1,433	$ 1,411