Derivative Instruments - Credit Derivatives (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Credit Derivatives - supplemental information
Tranche credit default swap realized credit loss protection	$ 1,000,000
Tranche credit default swap portfolio of exposure	10,000,000
Total credit derivatives and credit-related notes
Protection sold	(738,464,000,000)	$ (744,399,000,000)
Protection purchased with identical underlyings	749,766,000,000	761,256,000,000
Net protection (sold)/purchased	11,302,000,000	16,857,000,000
Other protection purchased	20,966,000,000	24,707,000,000
Total credit derivatives
Total credit derivatives and credit-related notes
Protection sold	(738,464,000,000)	(744,381,000,000)
Protection purchased with identical underlyings	749,766,000,000	761,256,000,000
Net protection (sold)/purchased	11,302,000,000	16,875,000,000
Other protection purchased	12,541,000,000	16,792,000,000
Credit default swaps
Total credit derivatives and credit-related notes
Protection sold	(697,220,000,000)	(690,224,000,000)
Protection purchased with identical underlyings	707,282,000,000	702,098,000,000
Net protection (sold)/purchased	10,062,000,000	11,874,000,000
Other protection purchased	4,053,000,000	5,045,000,000
Other credit derivatives
Total credit derivatives and credit-related notes
Protection sold	(41,244,000,000)	(54,157,000,000)
Protection purchased with identical underlyings	42,484,000,000	59,158,000,000
Net protection (sold)/purchased	1,240,000,000	5,001,000,000
Other protection purchased	8,488,000,000	11,747,000,000
Credit-related notes
Total credit derivatives and credit-related notes
Protection sold	0	(18,000,000)
Protection purchased with identical underlyings	0	0
Net protection (sold)/purchased	0	(18,000,000)
Other protection purchased	$ 8,425,000,000	$ 7,915,000,000