Investment in an Affiliate - Schedule of Difference between Carrying Value of Investment in Purchased Common Stock and Underlying Equity in Net Assets (Parenthetical) (Detail)	Dec. 31, 2015	Jul. 13, 2015
EnSync, Inc
Schedule of Equity Method Investments [Line Items]
Percentage of net assets	16.80%	16.80%

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant