Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 286,782	$ 60,591
Other comprehensive income before reclassification	362
Amounts reclassified from accumulated other comprehensive loss	203
Total other comprehensive income	565	1,243
Ending balance	301,693	157,718
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(8,585)
Other comprehensive income before reclassification	337
Total other comprehensive income	337
Ending balance	(8,248)
Retirement Related Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(2,467)
Other comprehensive income before reclassification	25
Amounts reclassified from accumulated other comprehensive loss	203
Total other comprehensive income	228
Ending balance	(2,239)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(11,052)	(5,072)
Ending balance	$ (10,487)	$ (3,829)