Warrant Transactions - Additional Information (Details) - $ / shares		1 Months Ended		3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 22, 2015	Jun. 30, 2017	Mar. 31, 2017	May 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Feb. 19, 2010	Mar. 31, 2006
Class of Warrant or Right [Line Items]
Warrants exercised (in shares)					675,000	1,763,340
Issuance of common stock (in shares)			9,200,000
Warrants outstanding (in shares)					0	675,000
Allen, F. Stephen Series 2
Class of Warrant or Right [Line Items]
Issuance of warrants to purchase common stock (in shares)							1,000,000
Warrants repurchased (in shares)	50,000
Allen F. Stephen Series 2 and 3
Class of Warrant or Right [Line Items]
Issuance of warrants to purchase common stock (in shares)								1,000,000
Exercise price of warrants (in dollars per share)				$ 3.55		$ 3.55	$ 3.55
Warrants exercised (in shares)				425,000		275,000
Issuance of common stock (in shares)				425,000		275,000
Warrants outstanding (in shares)						425,000
OTA LLC Series 2
Class of Warrant or Right [Line Items]
Exercise price of warrants (in dollars per share)		$ 3.55
Warrants exercised (in shares)		250,000
Issuance of common stock (in shares)		250,000
Warberg WF IV LP | F. Stephen Allen
Class of Warrant or Right [Line Items]
Number of warrants sold (in shares)						250,000
OTA LLC | Warberg WF IV LP | OTA LLC Series 2
Class of Warrant or Right [Line Items]
Number of warrants sold (in shares)						250,000
Minimum | Allen F. Stephen Series 2 and 3
Class of Warrant or Right [Line Items]
Exercise price of warrants (in dollars per share)								$ 4
Maximum | Allen F. Stephen Series 2 and 3
Class of Warrant or Right [Line Items]
Exercise price of warrants (in dollars per share)								$ 7