Stockholders' Equity Tax Benefit (Expense) on Net Activity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Tax Benefit (Expense)	$ 1	$ (10)
Pension Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Tax Benefit (Expense)	(4)	(7)
Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Tax Benefit (Expense)	$ 5	$ (3)