Accumulated other comprehensive loss - Components of 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	$ 336,934
Ending Balance	341,946
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(711)
Other comprehensive loss	(2,308)
Ending Balance	(3,019)
Neo Medical [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	711
Other comprehensive loss	(615)
Ending Balance	96
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive loss	(2,821)
Ending Balance	(2,821)
Other Investments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive loss	102
Ending Balance	$ 102