Changes in Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2022 USD ($)
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance, Amount	$ 873,799
Other comprehensive loss before reclassifications	(9,678)
Ending Balance, Amount	871,467
Cumulative Translation Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance, Amount	(532)
Other comprehensive loss before reclassifications	(3,025)
Ending Balance, Amount	(3,557)
Unrealized Gain on Investments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance, Amount	(807)
Other comprehensive loss before reclassifications	(6,653)
Ending Balance, Amount	(7,460)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance, Amount	(1,339)
Ending Balance, Amount	$ (11,017)