Summary of Significant Accounting Policies - Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property Plant and Equipment, Gross	$ 144,719	$ 142,680
Accumulated depreciation	(91,375)	(87,795)
Net property and equipment	53,344	54,885
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property Plant and Equipment, Gross	14,638	14,559
Building [Member]
Property, Plant and Equipment [Line Items]
Property Plant and Equipment, Gross	$ 38,225	38,059
Estimated Useful Life	31 years 6 months
Towers And Antennae [Member]
Property, Plant and Equipment [Line Items]
Property Plant and Equipment, Gross	$ 25,918	25,976
Towers And Antennae [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	7 years
Towers And Antennae [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	15 years
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property Plant and Equipment, Gross	$ 55,955	53,547
Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	15 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property Plant and Equipment, Gross	$ 7,129	7,189
Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	7 years
Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life	20 years
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property Plant and Equipment, Gross	$ 2,854	$ 3,350
Estimated Useful Life	5 years