Income Taxes (Detail) - USD ($)	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Income tax benefit from continuing operations	$ 0	$ 0

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 20
-Section 45
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=79507043&loc=d3e38976-109324

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