Shareholders' Equity - Treasury Stock (Details) - Treasury Stock - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020	Jan. 31, 2021
Schedule of Common Stock and Treasury Stock [Line Items]
Authorized share repurchase program	$ 1,000
Share repurchase cost	600
Share repurchase fees	$ 0
Number of shares repurchased	24,691
Stock repurchase program, remaining authorized repurchase amount	$ 400
Subsequent Event
Schedule of Common Stock and Treasury Stock [Line Items]
Authorized share repurchase program		$ 100
Stock repurchase program, remaining authorized repurchase amount		$ 500