Capital Stock and Series B Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
	Jul. 22, 2015	Jul. 23, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Class Of Stock [Line Items]
Authorized capital stock			50,000,000	50,000,000
Preferred stock, shares authorized			35,000,000	35,000,000
Preferred stock, shares issued			0	0
Preferred stock, shares outstanding			0	0
Shares issued in private placement			27,511,361	27,636,853
Aggregate proceeds received from offering, net of fees				$ 15,942	$ 11,138
Common Stock Purchase Agreement [Member]
Class Of Stock [Line Items]
Gross proceeds in private placement	$ 16,200
Shares issued in private placement	2,728,712	2,891,566
Common stock price		$ 4.15
Percentage of issued and outstanding common stock to be issued as private placement	12.00%	15.00%
Aggregate proceeds received from offering, net of fees	$ 15,900	$ 11,100
Financial advisor fees	$ 200
Percentage of commission		7.00%
Commission expense		$ 800
Common Stock Purchase Agreement [Member] | Officers And Directors [Member]
Class Of Stock [Line Items]
Shares issued in private placement	165,474
Common stock price	$ 6.11
Common Stock Purchase Agreement [Member] | Investor [Member]
Class Of Stock [Line Items]
Shares issued in private placement	2,563,238
Common stock price	$ 5.93
Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Rate of dividend accrued			7.00%
Series B Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, shares authorized			5,000,000	5,000,000
Preferred stock, shares issued			1,637,948	1,644,768
Preferred stock, shares outstanding			1,637,948	1,644,768
Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, shares authorized			40,000,000	40,000,000