Derivative Instruments - Credit Derivatives, Protection Sold, Notional and Fair Value (Details) - USD ($) $ in Millions	Jun. 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	$ (145,229)	$ (161,340)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - from 1-5 years	(432,215)	(521,673)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - more than 5 years	(51,668)	(55,451)
Total notional amount	(629,112)	(738,464)
Fair value of receivables	9,685	10,439
Fair value of payables	(5,311)	(8,451)
Net fair value	4,374	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	(103,901)	(115,443)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - from 1-5 years	(332,277)	(402,325)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - more than 5 years	(39,334)	(43,611)
Total notional amount	(475,512)	(561,379)
Fair value of receivables	5,678	5,720
Fair value of payables	(1,699)	(2,791)
Net fair value	3,979	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	(41,328)	(45,897)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - from 1-5 years	(99,938)	(119,348)
Protection sold credit derivatives and credit-related notes ratings/maturity profile - more than 5 years	(12,334)	(11,840)
Total notional amount	(153,600)	(177,085)
Fair value of receivables	4,007	4,719
Fair value of payables	(3,612)	(5,660)
Net fair value	$ 395	$ (941)