- Acquired Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 35,469	$ 35,221
Intangible assets, accumulated amortization	25,662	24,703
Finite-lived intangible assets, net	9,807	10,518
Subscriber relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	17,742	17,570
Intangible assets, accumulated amortization	10,825	10,337
Finite-lived intangible assets, net	6,917	7,233
Distribution rights
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	4,290	4,233
Intangible assets, accumulated amortization	1,799	1,731
Finite-lived intangible assets, net	2,491	2,502
Internally developed software
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	2,327	2,327
Intangible assets, accumulated amortization	2,327	2,327
Finite-lived intangible assets, net	0	0
Proprietary content
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	8,181	8,164
Intangible assets, accumulated amortization	7,812	7,439
Finite-lived intangible assets, net	369	725
Intellectual property
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	2,284	2,284
Intangible assets, accumulated amortization	2,284	2,284
Finite-lived intangible assets, net	0	0
Favorable lease
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	645	643
Intangible assets, accumulated amortization	615	585
Finite-lived intangible assets, net	$ 30	$ 58