Commitments and Contingencies - Schedule of Insurance Receivable for Claims (Detail) - General Liability [Member] - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Commitments And Contingencies Disclosure [Line Items]
Insurance receivable and indemnification asset for claims under a fully insured policy	$ 2,773	$ 2,773
Insurance receivable for claims that exceeded the stop loss limit	2	26
Total insurance receivables included in other non-current assets	$ 2,775	$ 2,799

Carrying amount due after one year of the balance sheet date (or one operating cycle, if longer) of amount due in settlement of a claim for reimbursement from an insurance company when the Company has suffered a loss covered under an insurance policy.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_InsuranceSettlementsReceivableNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant