Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
AOCI, Translation adjustments, net of tax	$ (32)		$ (31)
AOCI, Post-retirement benefits and other, net of tax	(49)		(49)
Accumulated other comprehensive loss, net of tax	(81)		$ (80)
Other comprehensive income (loss), translation adjustments, before reclassification adjustment, net of tax	(1)
Other comprehensive income (loss), before reclassification adjustment, net of tax	(1)
Other comprehensive loss, translation adjustments, net of tax	(1)	$ (3)
Other comprehensive loss, net of tax	$ (1)	$ (3)