Description of Business (Proposed Merger) (Details) - Twin Acquisition Corp. - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Business Acquisition [Line Items]
Proposed merger, agreement termination fee		$ 11.9
Professional fees	$ 2.0	$ 2.2
Contingent consideration, cash
Business Acquisition [Line Items]
Proposed merger, company shareholders' consideration in cash (per share)		$ 30.75
Proposed merger, consideration proration of final distribution (as a percentage)		60.00%
Contingent consideration, Cincinnati Bell common stock
Business Acquisition [Line Items]
Proposed merger, company shareholders' consideration in Cincinnati Bell common stock shares		1.6305
Proposed merger, consideration proration of final distribution (as a percentage)		40.00%
Contingent consideration, cash and Cincinnati Bell common stock mixture
Business Acquisition [Line Items]
Proposed merger, company shareholders' consideration in cash (per share)		$ 18.45
Proposed merger, company shareholders' consideration in Cincinnati Bell common stock shares		0.6522