Supplemental Income Statement Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Supplemental Income Statement Information
Interest expense	$ 104	$ 82
Interest income	(20)	(21)
Pension and postretirement net periodic benefit cost (benefit)	(36)	(19)
Total	$ 48	$ 42