Components of Income Tax Benefit (Expense) by Taxing Jurisdiction (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2017 USD ($)
Components Of Income Tax Expense Benefit [Line Items]
Current	$ (1)
Deferred	1,672
Total income tax benefit (expense)	1,671
Foreign Tax Authority
Components Of Income Tax Expense Benefit [Line Items]
Current	(1)
Deferred	1,672
Total income tax benefit (expense)	$ 1,671

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration