Restructuring Costs - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring and Related Activities [Abstract]
Restructuring costs, net	$ 5	$ 8	$ 10	$ 10
Restructuring Cost and Reserve [Line Items]
Restructuring costs, net	5	8	10	10
2020 Restructuring Plan
Restructuring and Related Activities [Abstract]
Restructuring costs, net	4	8	9	8
Restructuring Cost and Reserve [Line Items]
Restructuring costs, net	4	$ 8	9	8
Restructuring cost incurred to date	28		28
2020 Restructuring Plan \| Minimum
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	30		30
2020 Restructuring Plan \| Maximum
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	$ 35		$ 35
Accelerated Transformation Plan (ATP)
Restructuring and Related Activities [Abstract]
Restructuring costs, net				2
Restructuring Cost and Reserve [Line Items]
Restructuring costs, net				$ 2