Schedule of Shares Issued Upon Exercise of Warrants (Parenthetical) (Detail) - Series L	Mar. 31, 2017 $ / shares
Derivative [Line Items]
Warrant , exercise price aggregate	$ 1.90
Warrant , exercise price pre-funded	$ 1.89

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration