Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
Limit on NOL Carryforward Deduction	80.00%
Valuation allowance	$ 388	$ 638
Change in valuation allowance	250	15	$ 311
Gross interest (benefit) related to unrecognized tax	0	0	0
Unrecognized tax benefits	32	33	37	$ 36
Tax benefit related to change in valuation allowance	0	8	$ 679
Deferred Tax Asset, Operating Loss Carryforward
Income Tax Contingency [Line Items]
Valuation allowance	742	992
Valuation allowance on deferred tax assets
Income Tax Contingency [Line Items]
Valuation allowance	388	$ 638
Other Comprehensive Income (Loss) | Deferred Tax Asset, Capital Loss Carryforward
Income Tax Contingency [Line Items]
Valuation allowance	(354)
Other Net Realized Capital Gains (Losses) | Deferred Tax Asset, Capital Loss Carryforward
Income Tax Contingency [Line Items]
Valuation allowance	(354)
Continuing Operations
Income Tax Contingency [Line Items]
Change in valuation allowance	$ (250)