Deferred Income and Revenue Participation Rights - Participating Revenue Rights (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Deferred Revenue Arrangement [Line Items]
Deferred income and participating revenue rights	$ 4,643,750	$ 5,026,898
"Cambridge" Project [Member]
Deferred Revenue Arrangement [Line Items]
Deferred income and participating revenue rights	825,000	825,000
"Seattle" Project [Member]
Deferred Revenue Arrangement [Line Items]
Deferred income and participating revenue rights	62,500	62,500
Galt Resources, LLC (HMS Victory) [Member]
Deferred Revenue Arrangement [Line Items]
Deferred income and participating revenue rights	$ 3,756,250	3,756,250
Oceanica Call Option [Member]
Deferred Revenue Arrangement [Line Items]
Deferred income and participating revenue rights		$ 383,148

Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 13.A.3)
-URI http://asc.fasb.org/extlink&oid=65893310&loc=d3e214044-122780

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 605
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 13.A.4(a).Q1)
-URI http://asc.fasb.org/extlink&oid=65893310&loc=d3e214044-122780

Name:	us-gaap_DeferredRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant