Accrued Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued compensation	$ 19,750		$ 18,925
Accrued income tax and sales tax	23		71
Customer deposits	0		3,970
Provision for forward loss reserves	0		1,226
Other	6,040		4,137
Total	$ 25,813	$ 22,238	$ 28,329