Income Taxes - Narrative (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Feb. 18, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule of Equity Method Investments [Line Items]
Effective income tax rate		337.50%	20.60%	11.50%	16.60%
Income tax (provision) benefit		$ 27	$ (60)	$ (52)	$ (91)
Loss before income taxes and loss from investments in unconsolidated affiliates		8	$ (291)	(454)	$ (549)
Unrecognized tax benefits		187		187
Decrease in unrecognized tax benefits reasonably possible		$ 25		$ 25
Investment Services Business
Schedule of Equity Method Investments [Line Items]
Controlling interest sold (as a percent)	60.00%
Disposal Group, Held-for-sale or Disposed of by Sale
Schedule of Equity Method Investments [Line Items]
Tax expense	$ 112
Disposal Group, Held-for-sale or Disposed of by Sale | Investment Services Business
Schedule of Equity Method Investments [Line Items]
Tax expense	112
Pre-tax gain on sale	$ 428