Revenue Recognition - Schedule of Information about Receivables, Contract Assets and Contract Liabilities from Contracts with Customers (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Revenue From Contract With Customer [Abstract]
Receivables	$ 11,581	$ 18,014
Short-term contract assets	1,053	937
Long-term contract assets	528	30
Short-term contract liabilities (deferred revenue)	1,652	3,219
Long-term contract liabilities (deferred revenue)	$ 1,037	$ 61

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

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Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

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