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Restructuring Activities - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Restructuring Cost And Reserve [Line Items]
Restructuring expenses	$ 0	$ 0	$ 0	$ 0
Payments for restructuring				$ 59,000
Maximum [Member]
Restructuring Cost And Reserve [Line Items]
Payments for restructuring		$ 100,000
November 2018 Corporate Restructuring [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring activity, announcement date			Nov. 07, 2018