Changes in Accumulated Other Comprehensive Income (Loss) by Component (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	$ 682
Other comprehensive income (loss), net of tax	(156)	$ 123	$ (5)
Balance at end of period	1,916	682
Other comprehensive income (loss) attributable to noncontrolling interests, net of tax	(2)	2	(4)
Foreign currency translation adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	(263)	(367)	(315)
Other comprehensive income (loss) before reclassifications	(134)	104	(49)
Income tax provision (benefit)	0	0	(3)
Other comprehensive income (loss), net of tax	(132)	104	(52)
Balance at end of period	(395)	(263)	(367)
Pension and postretirement benefits:
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of year	(275)	(292)	(343)
Other comprehensive income (loss) before reclassifications	(47)	2	61
Reclassification to earnings	22	26	19
Other comprehensive income (loss) before tax	(25)	28	80
Income tax provision (benefit)	3	(11)	(29)
Other comprehensive income (loss), net of tax	(22)	17	51
Balance at end of period	$ (297)	$ (275)	$ (292)