Earnings Per Share, Share Repurchases and Dividends on Common Stock Share Repurchases (Details 1) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended			25 Months Ended	59 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Feb. 29, 2020	Jan. 25, 2021	Dec. 04, 2018	Sep. 16, 2015
Stock Repurchase [Line Items]
Shares Repurchased	1.4	3.2	3.8
September 2015 Share Repurchase Original Authorization
Stock Repurchase [Line Items]
Amount Authorized								$ 4,000
Total Shares Retired					15.4
Average Price Per Share					$ 260.33
Shares Repurchased	0.9	3.2	3.8
December 2018 Share Repurchase Program Original Authorization
Stock Repurchase [Line Items]
Amount Authorized							$ 3,000
Total Shares Retired				0.5
Average Price Per Share				$ 326.20
Shares Repurchased	0.5	0.0	0.0
Amount repurchased				$ 200
Amount remaining under authorization for share repurchases	$ 2,800			$ 2,800
January 2021 Share Repurchase Program [Member] | Subsequent Event [Member]
Stock Repurchase [Line Items]
Amount Authorized						$ 3,000
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased						5,800.0