Restructuring Activities - Summary of Charges Related to Restructuring Activities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost And Reserve [Line Items]
Accrued Restructuring Expenses	$ 66	$ 921
Expenses		4,783
Less: Payments	(66)	(5,638)
Accrued Restructuring Expenses		66
Severance Benefits and Related Costs Due to Workforce Reduction [Member]
Restructuring Cost And Reserve [Line Items]
Accrued Restructuring Expenses	66	921
Expenses		4,783
Less: Payments	$ (66)	(5,638)
Accrued Restructuring Expenses		$ 66