Stockholders' Equity - Schedule of Components of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ 158,088	$ 151,600	$ 141,189
Foreign currency translation	4,884	401	(3,257)
Reclassification of stranded tax effects from tax reform			(26)
Unrealized gain (loss) before reclassification, net of tax	(1,333)	(104)	12
Reclassification of AOCI/L to income, net of tax	616		129
Ending Balance	185,766	158,088	151,600
Marketable Investments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(115)
Reclassification of stranded tax effects from tax reform			(26)
Unrealized gain (loss) before reclassification, net of tax			12
Reclassification of AOCI/L to income, net of tax			129
Interest Rate Swap [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(104)
Unrealized gain (loss) before reclassification, net of tax	(1,333)	(104)
Reclassification of AOCI/L to income, net of tax	616
Ending Balance	(821)	(104)
Translation Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(4,753)	(5,154)	(1,897)
Foreign currency translation	4,884	401	(3,257)
Ending Balance	131	(4,753)	(5,154)
Total AOCI/L [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(4,857)	(5,154)	(2,012)
Foreign currency translation	4,884	401	(3,257)
Ending Balance	$ (690)	$ (4,857)	$ (5,154)