Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Assets measured at fair value on a recurring basis

	March 31, 2021								December 31, 2020
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
	(in millions)
Assets
Investments (Note 4)	$	11,128	$	171	$	41	$	11,340	$	8,546	$	174	$	41	$	8,761
Derivative contracts, at fair value (Note 6)		—		855		—		855		—		785		—		785
	$	11,128	$	1,026	$	41	$	12,195	$	8,546	$	959	$	41	$	9,546
Liabilities
Securities sold, not yet purchased (Note 4)	$	4,863	$	—	$	—	$	4,863	$	2,521	$	—	$	—	$	2,521
Derivative contracts, at fair value (Note 6)		—		584		—		584		11		628		—		639
Other liabilities		—		342		—		342		—		214		—		214
	$	4,863	$	926	$	—	$	5,789	$	2,532	$	842	$	—	$	3,374