Revenue - Condensed Consolidated Statement of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	$ 35,692	$ 30,458	$ 98,167	$ 83,233
Marketing, general and administrative	15,061	9,545	42,280	28,436
Other	1,331	(385)	(2,682)	(2,654)
Net income	9,019	52,406	89,937	(66,489)
Comprehensive income	$ 9,519	$ 51,504	$ 92,737	$ (68,256)
Net income per common share:
Basic (USD per share)	$ 0.01	$ 0.04	$ 0.07	$ (0.06)
Diluted (USD per share)	$ 0.01	$ 0.04	$ 0.07	$ (0.06)
Impact of ASC 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Marketing, general and administrative	$ (26)		$ (176)
Other	14		(28)
Net income	(1,293)		27
Comprehensive income	$ (1,293)		$ 27
Net income per common share:
Basic (USD per share)	$ 0.00		$ 0.00
Diluted (USD per share)	$ 0.00		$ 0.00
Legacy GAAP
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Marketing, general and administrative	$ 15,035		$ 42,104
Other	1,345		(2,710)
Net income	7,726		89,964
Comprehensive income	$ 8,226		$ 92,764
Net income per common share:
Basic (USD per share)	$ 0.01		$ 0.07
Diluted (USD per share)	$ 0.01		$ 0.07
Services
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	$ 29,898	$ 26,069	$ 83,903	$ 71,851
Cost of goods and services	9,429	9,315	27,984	27,325
Services | Impact of ASC 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	(1,243)		(98)
Services | Legacy GAAP
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	28,655		83,805
Subscriber equipment sales
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	5,794	4,389	14,264	11,382
Cost of goods and services	4,426	$ 2,905	10,768	$ 7,779
Subscriber equipment sales | Impact of ASC 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	(200)		(281)
Cost of goods and services	(138)		(202)
Subscriber equipment sales | Legacy GAAP
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	5,594		13,983
Cost of goods and services	$ 4,288		$ 10,566