Stock Options, Stock Purchase Plan and Warrants - Summary of Information on Warrants Outstanding (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2015	May. 03, 2010
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number outstanding	650,000
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 1.48	$ 1.50
Warrant One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number outstanding	450,000
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 1.50
Issued	May 03, 2010
Expired	May 02, 2017
Warrants Two [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number outstanding	200,000
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 1.43
Issued	Jan. 12, 2012
Expired	Jan. 12, 2017