Share Repurchase Program (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Stock Repurchase Program, Period in Force	3 years
Stock Repurchase Program, Authorized Amount	$ 1,000
Total amount paid (in millions)	$ 155	$ 249	$ 0