Allowance for Doubtful Accounts Receivable and Sales Returns (Additional Information) (Detail) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2016 USD ($) Customer	Mar. 31, 2015 USD ($) Customer	Dec. 31, 2015 Customer
Concentration Risk [Line Items]
Revenue | $	[1]	$ 28,230	$ 30,597
Mobile Services
Concentration Risk [Line Items]
Revenue | $		$ 16,465	$ 14,504
Accounts Receivable | Company A
Concentration Risk [Line Items]
Number of customers | Customer		1		1
Percentage by major customer		54.00%		52.00%
Accounts Receivable | Company B
Concentration Risk [Line Items]
Number of customers | Customer		1		1
Percentage by major customer		15.00%		12.00%
Revenue by Segment | Mobile Services | Company A
Concentration Risk [Line Items]
Number of customers | Customer		1	1
Percentage by major customer		30.00%	17.00%
Revenue | $		$ 8,400	$ 5,300
Revenue by Segment | Mobile Services | Company B
Concentration Risk [Line Items]
Number of customers | Customer		1
Percentage by major customer		12.00%
Revenue | $		$ 3,500

[1] Quarters ended March 31, 2016 quarter ended March 31, 2016Components of Revenue License Fees5,777 7,289Service Revenue22,453 23,308Net Revenue28,230 30,597