Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating Loss Carryforwards [Line Items]
Statutory rate of income taxes	21.00%	21.00%	21.00%	21.00%
Provision (credit) for income taxes	$ 48	$ (48)	$ 164	$ (52)
Separate Return Limitation Year Tax Rules
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards subject to SRLY tax rules will expire unutilized at December 31, 2021	$ 27		$ 27
Neon Capital Limited
Operating Loss Carryforwards [Line Items]
Provision (credit) for income taxes		$ 73