Leases - Finance Leases (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) renewal_option	Dec. 31, 2018 USD ($)
Capital Leased Assets [Line Items]
Number of lease renewal periods | renewal_option	2
Renewal option term	10 years
Renewal option term	5 years
Land
Capital Leased Assets [Line Items]
Finance lease ROU assets	$ 37.6
Building
Capital Leased Assets [Line Items]
Finance lease ROU assets	10.7
Capital lease asset, net of accumulated amortization		$ 11.4
Fiber Facilities
Capital Leased Assets [Line Items]
Finance lease ROU assets	1.1
Capital lease asset, gross		12.3
Substation equipment
Capital Leased Assets [Line Items]
Finance lease ROU assets	1.0
Capital lease asset, gross		0.1
Industrial Development Revenue Bond
Capital Leased Assets [Line Items]
Capital lease asset, gross	$ 133.1	$ 6.1
Nevada Broadband Telemedicine Initiative | Fiber Facilities
Capital Leased Assets [Line Items]
Renewal option term	25 years
Finance lease ROU assets	$ 10.5