Postretirement Benefits (Details 2) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Defined contribution plans
Costs related to defined contribution plans	$ 158	$ 95
U.S. Plans
Defined contribution plans
Costs related to defined contribution plans	137	73
Non-U.S. Plans
Defined contribution plans
Costs related to defined contribution plans	$ 21	$ 22