Discontinued Operations - Revenue by Service Offering (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Discontinued Operations
Other revenue	$ 35.0	$ 31.4	$ 34.7
Total revenue	704.9	725.7	730.2
Subscription services
Discontinued Operations
Revenue	648.7	672.0	672.1
Other business services
Discontinued Operations
Revenue	21.2	22.3	23.4
Other business services - Wholesale and colocation lease revenue
Discontinued Operations
Revenue	19.1	19.4	19.4
Residential Subscription | Subscription services
Discontinued Operations
Revenue	537.7	561.6	566.5
Residential Subscription | HSD
Discontinued Operations
Revenue	339.9	329.0	294.5
Residential Subscription | Video
Discontinued Operations
Revenue	173.5	204.1	236.4
Residential Subscription | Telephony
Discontinued Operations
Revenue	24.3	28.5	35.6
Business Subscription | Subscription services
Discontinued Operations
Revenue	111.0	110.4	105.6
Business Subscription | HSD
Discontinued Operations
Revenue	72.2	70.1	64.5
Business Subscription | Video
Discontinued Operations
Revenue	11.7	11.4	11.4
Business Subscription | Telephony
Discontinued Operations
Revenue	$ 27.1	28.9	29.7
Atlantic and Astound broadband markets | Discontinued Operations, Disposed of by sale
Discontinued Operations
Other revenue		13.0
Total revenue		308.3
Atlantic and Astound broadband markets | Discontinued Operations, Disposed of by sale | Subscription services
Discontinued Operations
Revenue		293.7
Atlantic and Astound broadband markets | Discontinued Operations, Disposed of by sale | Other business services
Discontinued Operations
Revenue		1.6
Atlantic and Astound broadband markets | Discontinued Operations, Disposed of by sale | Residential Subscription
Discontinued Operations
Revenue		264.8
Atlantic and Astound broadband markets | Discontinued Operations, Disposed of by sale | Residential Subscription | HSD
Discontinued Operations
Revenue		150.1
Atlantic and Astound broadband markets | Discontinued Operations, Disposed of by sale | Residential Subscription | Video
Discontinued Operations
Revenue		103.2
Atlantic and Astound broadband markets | Discontinued Operations, Disposed of by sale | Residential Subscription | Telephony
Discontinued Operations
Revenue		11.5
Atlantic and Astound broadband markets | Discontinued Operations, Disposed of by sale | Business Subscription
Discontinued Operations
Revenue		28.9
Atlantic and Astound broadband markets | Discontinued Operations, Disposed of by sale | Business Subscription | HSD
Discontinued Operations
Revenue		17.8
Atlantic and Astound broadband markets | Discontinued Operations, Disposed of by sale | Business Subscription | Video
Discontinued Operations
Revenue		2.7
Atlantic and Astound broadband markets | Discontinued Operations, Disposed of by sale | Business Subscription | Telephony
Discontinued Operations
Revenue		$ 8.4
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale
Discontinued Operations
Other revenue			18.3
Total revenue			418.2
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale | Subscription services
Discontinued Operations
Revenue			398.0
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale | Other business services
Discontinued Operations
Revenue			1.9
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale | Residential Subscription
Discontinued Operations
Revenue			359.9
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale | Residential Subscription | HSD
Discontinued Operations
Revenue			185.6
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale | Residential Subscription | Video
Discontinued Operations
Revenue			157.4
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale | Residential Subscription | Telephony
Discontinued Operations
Revenue			16.9
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale | Business Subscription
Discontinued Operations
Revenue			38.1
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale | Business Subscription | HSD
Discontinued Operations
Revenue			22.6
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale | Business Subscription | Video
Discontinued Operations
Revenue			3.6
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale | Business Subscription | Telephony
Discontinued Operations
Revenue			$ 11.9