Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2019

Fair Value Disclosures [Abstract]

Assets measured at fair value on a recurring basis

	June 30, 2019								December 31, 2018
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets	(in millions)
Investments (Note 4)	$	8,327	$	327	$	3	$	8,657	$	7,493	$	317	$	372	$	8,182
Derivative contracts, at fair value (Note 6)(1)	6		209		—		215		7		517		—		524
	$	8,333	$	536	$	3	$	8,872	$	7,500	$	834	$	372	$	8,706
Liabilities
Securities sold, not yet purchased (Note 4)	$	146	$	—	$	—	$	146	$	468	$	—	$	—	$	468
Other liabilities	—		16		—		16		—		2		—		2
Derivative contracts, at fair value (Note 6)	—		902		—		902		—		36		—		36
	$	146	$	918	$	—	$	1,064	$	468	$	38	$	—	$	506

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

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

	Six Months Ended June 30,
	2019			2018
	(in millions)
Balance at January 1	$	372		$	278
Net gains recognized in income	89			55
Sales	(458		)	—
Balance at June 30	$	3		$	333