Prior Periods Financial Statement Revision - Schedule of Correction of Misstatements and Revision on Condensed Consolidated Statements of Cash Flow (Phantom) (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2017
Accounting Changes and Error Corrections [Abstract]
Depreciation and amortization	$ 1,611	$ 7,722

Amount of depreciation and amortization expense attributable to disposal group, including, but not limited to, discontinued operation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721673-107760

Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration