Earnings Per Share (Current Stock Repurchase Program) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($) shares
Shares Repurchased
As of December 31, 2019	132,759,876
As of March 31, 2020	135,824,676
Cost
As of December 31, 2019 | $	$ 5,602
As of March 31, 2020 | $	$ 5,727
Stock Repurchase Program, Post Spin-Off [Member]
Shares Repurchased
Repurchases	3,100,000
Cost
Repurchases | $	$ 125
Stock Repurchase Program [Member]
Shares Repurchased
As of December 31, 2019	108,200,000
As of March 31, 2020	111,300,000