Revenue - Summary of Opening and Closing Balances of Company's Receivables and Current and Long-term Contract Liabilities (Detail) - Accounting Standards Update 2014-09 [Member] - USD ($) $ in Thousands	Mar. 31, 2018	Jan. 01, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Receivables	$ 188,817
Contract liabilities - current	5,450
Contract liabilities - noncurrent	5,638
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Receivables		$ 150,151
Contract liabilities - current		5,736
Contract liabilities - noncurrent		$ 5,222
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Receivables	38,666
Contract liabilities - current	(286)
Contract liabilities - noncurrent	$ 416