Shareholders' Equity - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period			$ 1,619
Balance at end of period	$ (106)		(106)
Other comprehensive income (loss) attributable to noncontrolling interests	10	$ (22)	(3)	$ (17)
Accumulated Other Comprehensive Income (Loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(874)	(680)	(711)	(692)
Balance at end of period	(854)	(752)	(854)	(752)
Foreign currency translation adjustments and other:
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(533)	(383)	(369)	(395)
Other comprehensive income (loss) before reclassifications	33	(77)	(132)	(66)
Reclassification from other comprehensive income (loss)	0	0	0	0
Other comprehensive income (loss)	33	(77)	(132)	(66)
Income tax benefit (provision)	0	2	1	3
Balance at end of period	(500)	(458)	(500)	(458)
Pensions and other postretirement benefits:
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(343)	(298)	(342)	(297)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Reclassification from other comprehensive income (loss)	(14)	2	(10)	5
Other comprehensive income (loss)	(14)	2	(10)	5
Income tax benefit (provision)	0	1	(5)	(3)
Balance at end of period	(357)	(295)	(357)	(295)
Cash flow hedge instruments:
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	2	1	0	0
Other comprehensive income (loss) before reclassifications	1	(1)	3	0
Reclassification from other comprehensive income (loss)	0	1	0	1
Other comprehensive income (loss)	1	0	3	1
Income tax benefit (provision)	0	0	0	0
Balance at end of period	$ 3	$ 1	$ 3	$ 1