Transaction Costs and Other Charges (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Unusual or Infrequent Items, or Both [Abstract]
Transaction costs and other charges	$ 89	$ 19
Transaction costs and other charges, after-tax and noncontrolling interest	81	$ 18
Transaction costs and other charges, effect on diluted earnings per share (USD per share)		$ 0.06
Transaction costs	56
Transaction costs, after-tax	53
Other charges	33
Other charges, after-tax	$ 28