Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounting Policies [Line Items]
Depreciation expense	$ 484,000	$ 377,000	$ 565,000
Undelivered elements (primarily consists of training)	1,823,000	1,723,000
Provision for sales returns	110,000	110,000
Extended warranty contracts	1,600,000	1,500,000
Exclusive license revenue	0	0	64,000
Advertising costs	1,500,000	907,000	444,000
Compensation cost related to stock options	1,609,000	1,600,000	1,528,000
Net impact of share based compensation expense to earnings per diluted share	$ (0.05)	$ (0.05)	$ (0.05)
Total unrecognized compensation cost	$ 2,700,000	$ 1,900,000
Unrecognized share based compensation cost to be recognized over weighted-average period	1 year 6 months
Outstanding stock options and warrants excluded from diluted loss per share	6,039,000	4,713,000	4,626,000