Accumulated other comprehensive loss - Components of Changes in Accumulated Other Comprehensive Loss (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($)
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ 336,934
Ending Balance	335,575
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(711)
Other comprehensive income (loss)	(488)
Ending Balance	(1,199)
Neo Medical [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	711
Other comprehensive income (loss)	(740)
Ending Balance	(29)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss)	(1,162)
Ending Balance	(1,162)
Other Investments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss)	66
Ending Balance	$ 66