Summary of Significant Accounting Policies - Property and Equipment (Details) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Property and equipment
Property and equipment, Gross	$ 144,276,000	$ 151,553,000
Accumulated depreciation	(97,863,000)	(99,646,000)
Net property and equipment	46,413,000	51,907,000
Continuing Operations
Property and equipment
Depreciation expense	4,789,000	5,013,000
Land and land improvements
Property and equipment
Property and equipment, Gross	13,468,000	15,524,000
Building
Property and equipment
Property and equipment, Gross	$ 41,490,000	41,292,000
Estimated Useful Life	31 years 6 months
Towers and antennae
Property and equipment
Property and equipment, Gross	$ 21,603,000	27,969,000
Towers and antennae | Minimum
Property and equipment
Estimated Useful Life	7 years
Towers and antennae | Maximum
Property and equipment
Estimated Useful Life	15 years
Equipment
Property and equipment
Property and equipment, Gross	$ 56,687,000	55,647,000
Equipment | Minimum
Property and equipment
Estimated Useful Life	3 years
Equipment | Maximum
Property and equipment
Estimated Useful Life	15 years
Furniture, fixtures and leasehold improvements
Property and equipment
Property and equipment, Gross	$ 8,359,000	8,314,000
Furniture, fixtures and leasehold improvements | Minimum
Property and equipment
Estimated Useful Life	7 years
Furniture, fixtures and leasehold improvements | Maximum
Property and equipment
Estimated Useful Life	20 years
Vehicles
Property and equipment
Property and equipment, Gross	$ 2,669,000	$ 2,807,000
Estimated Useful Life	5 years