Equity - AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Loss
Balance at the beginning of the period	$ 2,720
Balance at the end of the period	2,606
Cumulative Translation Adjustment
Accumulated Other Comprehensive Loss
Balance at the beginning of the period	(1,089)	$ (1,080)
Other comprehensive income (loss) before reclassification adjustments	(134)	1
Net other comprehensive income (loss)	(134)	1
Balance at the end of the period	(1,223)	(1,079)
(Loss) Gain on Hedging Activities
Accumulated Other Comprehensive Loss
Balance at the beginning of the period	(9)	(5)
Other comprehensive income (loss) before reclassification adjustments	(46)	(12)
Amount reclassified from accumulated OCI	6	2
Tax benefit	10	3
Net other comprehensive income (loss)	(30)	(7)
Balance at the end of the period	(39)	(12)
Pension and other postretirement plans
Accumulated Other Comprehensive Loss
Balance at the beginning of the period	(60)	(69)
Balance at the end of the period	(60)	(69)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Loss
Balance at the beginning of the period	(1,158)	(1,154)
Other comprehensive income (loss) before reclassification adjustments	(180)	(11)
Amount reclassified from accumulated OCI	6	2
Tax benefit	10	3
Net other comprehensive income (loss)	(164)	(6)
Balance at the end of the period	$ (1,322)	$ (1,160)