Operating Segment and Enterprise Wide Reporting - Schedule of Revenues by Geographic Destination, Based on Location Products and Services and as a Percentage of Total Revenues (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 448,984	$ 461,697	$ 357,575
Revenues by geographical area percentage	100.00%	100.00%	100.00%
United States [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 356,288	$ 362,867	$ 274,151
Revenues by geographical area percentage	79.00%	79.00%	77.00%
Europe (Excluding United Kingdom) [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 34,897	$ 32,585	$ 29,741
Revenues by geographical area percentage	8.00%	7.00%	8.00%
United Kingdom [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 15,741	$ 21,316	$ 15,273
Revenues by geographical area percentage	4.00%	4.00%	4.00%
Canada [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 14,005	$ 17,246	$ 15,569
Revenues by geographical area percentage	3.00%	4.00%	4.00%
Asia Pacific [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 22,969	$ 22,842	$ 17,839
Revenues by geographical area percentage	5.00%	5.00%	5.00%
Other [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 5,084	$ 4,841	$ 5,002
Revenues by geographical area percentage	1.00%	1.00%	2.00%