Accounts Receivable - Summary of Accounts Receivable (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]
Trade receivables	$ 101,864	$ 152,476
Other receivables	7,083	10,016
Accounts receivable, gross	108,947	162,492
Allowance for doubtful accounts	(4,298)	(2,325)
Accounts receivable, net	$ 104,649	$ 160,167