Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended				12 Months Ended
	Jan. 15, 2014	Jul. 31, 2016	Jun. 29, 2016	Jun. 30, 2015	Jan. 31, 2014	Dec. 31, 2016	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2013
Shareholders Equity [Line Items]
Common stock and warrants issued, Value					$ 15,000
Common Stock, shares issued						95,645,224		89,762,872
Common Stock, shares outstanding						95,645,224		89,762,872
Stock Issued During Period, Value, Stock Options Exercised							$ 436
Stock Issued During Period Shares New Issues	5,000,000		5,882,352		5,000,000
Stock Issued During Period, Value, New Issues						$ 4,388	13,813
Stockholders Equity						$ 8,240	$ 14,917	$ 9,818	$ 4,783
Investor Warrant
Shareholders Equity [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 2.30
Class of Warrant or Right, Warrant Expiration period		5 years
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		2,941,176
Warrant
Shareholders Equity [Line Items]
Class of Warrant or Right, Exercise Price of Warrants or Rights					$ 4.74
Stock Issued During Period Shares New Issues	2,500,000		2,941,176		2,500,000
Stock Issued During Period, Value, New Issues	$ 15,000		$ 10,000	$ 25,000
Common Stock
Shareholders Equity [Line Items]
Exercise of stock options (in shares)							525,000
Stock Issued During Period, Value, Stock Options Exercised							$ 1
Stock Issued During Period Shares New Issues		5,882,352				5,882,000	5,000,000
Stock Issued During Period, Value, New Issues		$ 10,000				$ 6	$ 5
Stockholders Equity						$ 96	$ 90	$ 90	$ 84
Common Stock | Former Director
Shareholders Equity [Line Items]
Exercise of stock options (in shares)							525,000
Stock Issued During Period, Value, Stock Options Exercised							$ 400
Placement Agent
Shareholders Equity [Line Items]
Common stock and warrant issued, shares					250,000
Class of Warrant or Right, Exercise Price of Warrants or Rights		$ 2.46
Class of Warrant or Right, Warrant Expiration period		5 years
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		250,000