Earnings Per Share, Share Repurchases and Dividends on Common Stock (Unaudited) (Details 1) - September 2015 Share Repurchase Program Original Authorization - USD ($) $ / shares in Units, shares in Millions, $ in Millions	9 Months Ended		30 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 16, 2015
Share Repurchase [Line Items]
Amount Authorized				$ 4,000
Shares Retired			8.1
Average Cost Per Share			$ 230.14
Shares Repurchased	0.7	1.6
Share Repurchases - Notes to Table
Shares repurchased amount			$ 1,900
Amount remaining under authorization for share repurchases	$ 2,100		$ 2,100