Debt and Other Financing Arrangements - Cincinnati Bell Telephone Notes (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended					12 Months Ended
	Nov. 30, 1998	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Gain on Extinguishment of Debt		$ 3.2	$ 4.8	$ 11.4	$ 5.2	$ 2.4	$ (3.2)	$ (19.0)	$ (20.9)
Cincinnati Bell Telephone Senior Notes due 2028 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Unsecured Debt	$ 150.0
Debt Instrument, Interest Rate, Stated Percentage		6.30%					6.30%
Customary Events of Default Amount for Existing Debt Instruments		$ 20.0					$ 20.0
Cincinnati Bell Telephone Senior Notes due 2028 [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount								$ 40.8	$ 5.8
Debt Instrument, Redemption Price, Percentage								92.232%	90.84%
Gain on Extinguishment of Debt								$ (2.8)	$ (0.5)