Accounts Payable and Accrued Expenses - Schedule of Accounts Payable and Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016
Payables and Accruals [Abstract]
Accounts payable	$ 4,089		$ 3,207
Accrued inventories in-transit	86		313
Accrued other miscellaneous expenses	1,628		2,240
Accrued restructuring	493		0
Accrued compensation	3,674		5,042
Income taxes payable	2,194		1,344
Accrued warranty	1,852	$ 2,026	2,344	$ 2,694	$ 2,774	$ 3,601
Total	$ 14,016		$ 14,490