Shareholders' Equity - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 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	$ 349		349
Other comprehensive income (loss) attributable to noncontrolling interests	7	$ (1)	(13)	$ 5
Foreign currency translation adjustments and other:
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(568)	(366)	(369)	(395)
Other comprehensive income (loss) before reclassifications	34	(16)	(165)	11
Reclassification from other comprehensive income (loss)	0	0	0	0
Other comprehensive income (loss)	34	(16)	(165)	11
Income tax benefit (provision)	1	(1)	1	1
Balance at end of period	(533)	(383)	(533)	(383)
Pensions and other postretirement benefits:
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(338)	(296)	(342)	(297)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Reclassification from other comprehensive income (loss)	1	2	4	3
Other comprehensive income (loss)	1	2	4	3
Income tax benefit (provision)	(6)	(4)	(5)	(4)
Balance at end of period	(343)	(298)	(343)	(298)
Cash flow hedge instruments:
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(2)	4	0	0
Other comprehensive income (loss) before reclassifications	5	(3)	2	1
Reclassification from other comprehensive income (loss)	0	0	0	0
Other comprehensive income (loss)	5	(3)	2	1
Income tax benefit (provision)	(1)	0	0	0
Balance at end of period	2	1	2	1
Accumulated Other Comprehensive Income (Loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	(908)	(658)	(711)	(692)
Balance at end of period	$ (874)	$ (680)	$ (874)	$ (680)