Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Assets measured at fair value on a recurring basis

	December 31, 2019								December 31, 2018
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets	(in millions)
Investments (Note 4)	$	9,448	$	281	$	3	$	9,732	$	7,493	$	317	$	372	$	8,182
Derivative contracts, at fair value (Note 6)(1)	—		182		—		182		7		517		—		524
	$	9,448	$	463	$	3	$	9,914	$	7,500	$	834	$	372	$	8,706
Liabilities
Securities sold, not yet purchased (Note 4)	$	1,190	$	—	$	—	$	1,190	$	468	$	—	$	—	$	468
Other liabilities	—		7		6		13		—		2		—		2
Derivative contracts, at fair value (Note 6)	—		1,224		—		1,224		—		36		—		36
	$	1,190	$	1,231	$	6	$	2,427	$	468	$	38	$	—	$	506

⁽¹⁾Amounts are classified within other assets in our consolidated balance sheets.

Assets measured at fair value on a recurring basis for which we use Level 3 inputs to determine fair value

	Year Ended December 31,
	2019		2018
	(in millions)
Balance at January 1	$	372	$	278
Net gains recognized in income	89		95
Sales	(458)		—
Other	—		(1)
Balance at December 31	$	3	$	372