Fixed Assets, Net - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment
Depreciation expense	$ 22,900,000	$ 22,700,000	$ 13,700,000
Impairment charges			0
Software development costs capitalized	2,000,000.0	5,900,000	2,400,000
Amortization of software development costs	1,300,000	2,000,000.0	$ 900,000
Software, including software development costs
Property, Plant and Equipment
Impairment charges	$ 6,000,000.0	$ 5,000,000.0