Revenue - Summary of Opening and Closing Balances of Company's Receivables and Current and Long-term Contract Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Customer receivables	$ 97,566
Contract liabilities - current	5,810
Contract liabilities - noncurrent	8,354
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Customer 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]
Customer receivables	(52,585)
Contract liabilities - current	74
Contract liabilities - noncurrent	$ 3,132