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Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Unrecognized Tax Benefits	$ 15	$ 15	$ 15	$ 15	$ 15	$ 15	$ 14	$ 14
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			(6)
Effective Income Tax Rate Reconciliation, Noncontrolling Interest Income (Loss), Amount	0	5	0	5
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	1	(6)	(6)	(6)
Effective Income Tax Rate Reconciliation, Disposition of Business, Amount	0	(8)	(5)	(8)
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	(5)	$ 0	(5)	0
Non-insurance carryback [Member]
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount				(11)
Insurance Carryback Income Tax [Member]
Operating Loss Carryforwards [Line Items]
Effective Income Tax Rate Reconciliation, Noncontrolling Interest Income (Loss), Amount				$ (5)
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards	23		23
Deferred Tax Assets, Valuation Allowance	$ 4		$ 4