Derivative Instruments - Credit Derivatives, Protection Sold, Notional and Fair Value (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
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	$ (145,878)	$ (161,340)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - from 1-5 years	(420,195)	(521,673)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - more than 5 years	(100,792)	(55,451)
Total notional amount	(666,865)	(738,464)
Fair value of receivables	10,320	10,439
Fair value of payables	(4,675)	(8,451)
Net fair value	5,645	1,988
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	(106,698)	(115,443)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - from 1-5 years	(316,946)	(402,325)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - more than 5 years	(75,615)	(43,611)
Total notional amount	(499,259)	(561,379)
Fair value of receivables	5,621	5,720
Fair value of payables	(1,260)	(2,791)
Net fair value	4,361	2,929
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	(39,180)	(45,897)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - from 1-5 years	(103,249)	(119,348)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - more than 5 years	(25,177)	(11,840)
Total notional amount	(167,606)	(177,085)
Fair value of receivables	4,699	4,719
Fair value of payables	(3,415)	(5,660)
Net fair value	$ 1,284	$ (941)