Restructuring - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Dec. 30, 2018	Sep. 30, 2020
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	$ 8
2020 Reorganization [Member]
Restructuring Cost And Reserve [Line Items]
Severance costs	7
Restructuring charges expected remainder of fiscal 2020 and thereafter	4
Restructuring cash payments of fiscal year	1
Restructuring cash payments through the reminder of fiscal 2020 and thereafter	10
Accrued severance charges	6
Purification Solutions Transformation Plan [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring cash payments of fiscal year	8
Accrued severance charges	1
Restructuring Charges	10	$ 8	$ 9
Restructuring cash payments through the reminder of fiscal 2020	1
Purification Solutions Transformation Plan [Member] | Maximum [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring Charges	$ 1