Restructuring Programs - Certain Related Costs Incurred in Connection with Restructuring Programs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost and Reserve [Line Items]
Related restructuring costs	$ 8	$ 5	$ 4	$ 17
Retention related severance/bonuses
Restructuring Cost and Reserve [Line Items]
Related restructuring costs	3	4	(1)	11
Contractual severance costs
Restructuring Cost and Reserve [Line Items]
Related restructuring costs	3	0	3	4
Consulting and other costs
Restructuring Cost and Reserve [Line Items]
Related restructuring costs	$ 2	$ 1	$ 2	$ 2