Fair Value Measurements - Fair Value of Gross Position of Derivative Contracts in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Other current assets
Derivatives, Fair Value [Line Items]
Net amounts presented	$ (257)	$ 1,750
Other long-term liabilities
Derivatives, Fair Value [Line Items]
Net amounts presented	(2,847)	(1,380)
Designated as hedging instruments:
Derivatives, Fair Value [Line Items]
Gross amounts recognized	(3,673)	(1,524)
Gross amounts offset	477	2,237
Net amounts	(3,196)	713
Not designated as hedging instruments:
Derivatives, Fair Value [Line Items]
Gross amounts recognized	(177)	(544)
Gross amounts offset	269	201
Net amounts	$ 92	$ (343)

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value of the assets less the liabilities of a derivative or group of derivatives.

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