Income Taxes - Deferred Taxes Included in Consolidated Balance Sheets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Taxes.
Other assets	$ 178	$ 178
Deferred taxes	(109)	(110)
Net deferred taxes	69	$ 68
Deferred tax benefit associated with reduction in valuation allowance	31
Deferred tax benefit associated with reduction in valuation allowance allocated to income from continuing operations	28
Deferred tax benefit associated with reduction in valuation allowance allocated to other comprehensive income	$ 3