Commitments and Contingencies (Details) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Aug. 31, 2015 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) item	Jun. 30, 2016 USD ($)	Aug. 31, 2014 USD ($)
Jointly Owned Utility Plant Interests [Line Items]
CAF annual funding	$ 4.4
Period of support service				6 years
Number of eligible locations to offer broadband | item				11,000
Revenue recognized from CAF first year funds		$ 1.1	$ 1.1	$ 2.2	$ 2.2
Jointly owned utility plant
Jointly Owned Utility Plant Interests [Line Items]
Cost of construction						$ 235.0
Company investment in construction costs of plant						$ 25.0
Paid to the cable contractor for the cable build		19.5		$ 19.5
Period of up-front payment received				25 years
Proceeds from sale of capacity				$ 27.0
Upfront payment received				7.2
Escrow deposit		$ 5.0		$ 5.0
Minimum
Jointly Owned Utility Plant Interests [Line Items]
Downstream broadband service data transfer rate (Mbps)				10
Upstream broadband service data transfer rate (Mbps)				1