Leases - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Lessee Lease Description [Line Items]
Operating lease, description		The Company has commitments under operating leases for office space and radio tower sites used in its operations. Our leases have initial lease terms that expire between 2019 and 2082, most of which include options to extend or renew the leases.
Lessee, operating lease, existence of option to extend		true
Operating lease, options to extend		Our leases have initial lease terms that expire between 2019 and 2082, most of which include options to extend or renew the leases.
Rental expenses	$ 1,100		$ 2,800
Additional operating leases liability		$ 5,800
Additional operating leases expected to commence		15 years 6 months
Minimum
Lessee Lease Description [Line Items]
Initial lease term		2019
Rental expenses		$ 3
Maximum
Lessee Lease Description [Line Items]
Initial lease term		2082
Rental expenses		$ 500