Commitments and Contingencies - Additional Information (Detail) $ in Thousands	Dec. 31, 2016 USD ($)
Trade Letter of Credit
Commitments and Contingencies [Line Items]
Letter of credit to support purchase obligation	$ 7,597
Standby Letters of Credit
Commitments and Contingencies [Line Items]
Letter of credit to support purchase obligation	$ 11,799

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant