Significant Risk Concentrations - Additional Information (Detail)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015 USD ($) Customer	Sep. 30, 2014 USD ($) Customer	Sep. 30, 2015 USD ($) Customer Agreement	Sep. 30, 2014 USD ($) Customer	Dec. 31, 2014 USD ($) Customer
Concentration Risk [Line Items]
Total revenue	$ 26,435,000	$ 24,535,000	$ 81,573,000	$ 70,321,000
Accounts receivable	15,560,000		$ 15,560,000		$ 13,626,000
Expiration date one of OEM Distribution agreements for embedded operating systems			Jun. 30, 2016
Number of OEM Distribution agreements for embedded operating systems | Agreement			2
Expiration date of OEM Distribution agreements for mobile operating systems, non-EMEA			Jun. 30, 2016
Number of OEM Distribution agreements for mobile operating systems | Agreement			4
Cost of revenue-service [Member]
Concentration Risk [Line Items]
Earnings under the rebate program	91,000	64,000	$ 257,000	233,000
Reduction in marketing expense in the future [Member]
Concentration Risk [Line Items]
Earnings under the rebate program	212,000	$ 149,000	599,000	$ 543,000
Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Total revenue	2,800,000		13,500,000
Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Accounts receivable	$ 3,500,000		$ 3,500,000
Revenue [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of customer account as major customer | Customer	1	1	1	1
Concentration risk, percentage	11.00%	18.00%	17.00%	11.00%
Revenue [Member] | Customer accounted for 10% or more [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of customer account as major customer | Customer	0	0	0	0
Accounts receivable [Member] | Customer accounted for 10% or more [Member] | Credit Concentration Risk [Member]
Concentration Risk [Line Items]
Number of customer account as major customer | Customer			1		0
Concentration risk, percentage			23.00%