Basis of Presentation Narrative (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2017 USD ($) source	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Property, Plant and Equipment [Line Items]
Number of primary revenue sources | source	3
Service provider contract term	1 year
Service provider contract renewal term	1 year
Sales returns period	1 year
Reclassification from tax windfall benefit from stock options	$ (67,549)	$ (201)
Reclassification to deferred income taxes	24,736	7,940
Increase to additional paid-in capital			$ 12
Increase to deferred tax assets	23,746		16,752
Accumulated deficit	(104,100)		(117,909)
Additional paid-in capital	$ 314,919		308,697
Software Development
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Minimum
Property, Plant and Equipment [Line Items]
Subscriber contract term	3 years
Reserve for sales returns, percentage	2.00%
Maximum
Property, Plant and Equipment [Line Items]
Subscriber contract term	5 years
Reserve for sales returns, percentage	4.50%
Activation Fees
Property, Plant and Equipment [Line Items]
Deferred revenue	$ 10,900		11,200
Activation Fees | Minimum
Property, Plant and Equipment [Line Items]
Period of revenue recognition	12 months
Activation Fees | Maximum
Property, Plant and Equipment [Line Items]
Period of revenue recognition	10 years
Accounting Standards Update 2016-09, Statutory Tax Withholding Component
Property, Plant and Equipment [Line Items]
Reclassification from tax windfall benefit from stock options		500
Reclassification to deferred income taxes		$ 500
Accounting Standards Update 2016-09
Property, Plant and Equipment [Line Items]
Increase to deferred tax assets			100
Accumulated deficit			100
Additional paid-in capital			$ 100
15 Largest Service Providers | Service Provider Concentration Risk | Revenue
Property, Plant and Equipment [Line Items]
Concentration risk percentage	61.00%