Equity Equity (Share Repurchase Program) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity, Class of Treasury Stock [Line Items]
Treasury Stock, Value, Acquired, Cost Method	$ 163	$ 101	$ 300
Share Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Treasury Stock, Shares, Acquired	1,074,413	546,614
Treasury Stock, Value, Acquired, Cost Method	$ 153	$ 80
Treasury Stock Acquired, Average Cost Per Share	$ 142.05	$ 146.00