Shareholders' Equity - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period			$ 1,916
Balance at end of period	$ 1,837		1,837
Other comprehensive income (loss) attributable to noncontrolling interests	(22)	$ (3)	(17)	$ (2)
Foreign currency translation adjustments and other
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(383)	(336)	(395)	(263)
Other comprehensive income (loss) before reclassifications adjustments	(77)	(28)	(66)	(103)
Reclassification from other comprehensive income (loss)	0	0	0	0
Other comprehensive income (loss)	(77)	(28)	(66)	(103)
Income tax provision (benefit)	2	0	3	2
Balance at end of period	(458)	(364)	(458)	(364)
Pensions and other postretirement benefits
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(298)	(268)	(297)	(275)
Other comprehensive income (loss) before reclassifications adjustments	0	0	0	0
Reclassification from other comprehensive income (loss)	2	5	5	14
Other comprehensive income (loss)	2	5	5	14
Income tax provision (benefit)	1	(1)	(3)	(3)
Balance at end of period	(295)	(264)	(295)	(264)
Cash flow hedge instruments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	1	0	0	0
Other comprehensive income (loss) before reclassifications adjustments	(1)	0	0	0
Reclassification from other comprehensive income (loss)	1	0	1	0
Other comprehensive income (loss)	0	0	1	0
Income tax provision (benefit)	0	0	0	0
Balance at end of period	$ 1	$ 0	$ 1	$ 0