Discontinued Operations - Revenue by Service Offering (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Discontinued Operations
Total revenue	$ 173.7	$ 184.0	$ 524.4	$ 547.4
Subscription services
Discontinued Operations
Revenue	160.4	170.3	485.6	506.9
Other business services
Discontinued Operations
Revenue	5.4	5.6	16.1	16.9
Other business services - Wholesale and colocation lease revenue
Discontinued Operations
Revenue	4.8	4.8	14.4	14.6
Other revenue
Discontinued Operations
Other revenue	7.9	8.1	22.7	23.6
Residential Subscription | Subscription services
Discontinued Operations
Revenue	132.7	142.6	402.4	424.6
Residential Subscription | HSD
Discontinued Operations
Revenue	84.2	85.6	251.1	246.6
Residential Subscription | Video
Discontinued Operations
Revenue	42.4	50.0	132.8	156.1
Residential Subscription | Telephony
Discontinued Operations
Revenue	6.1	7.0	18.5	21.9
Business Subscription | Subscription services
Discontinued Operations
Revenue	27.7	27.7	83.2	82.3
Business Subscription | HSD
Discontinued Operations
Revenue	18.1	17.7	53.9	52.0
Business Subscription | Video
Discontinued Operations
Revenue	2.9	2.8	8.8	8.4
Business Subscription | Telephony
Discontinued Operations
Revenue	$ 6.7	7.2	$ 20.5	21.9
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale or Disposed of by Sale
Discontinued Operations
Total revenue		83.7		293.9
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale or Disposed of by Sale | Subscription services
Discontinued Operations
Revenue		79.5		280.1
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale or Disposed of by Sale | Other business services
Discontinued Operations
Revenue		0.6		1.6
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale or Disposed of by Sale | Other revenue
Discontinued Operations
Other revenue		3.6		12.2
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale or Disposed of by Sale | Residential Subscription
Discontinued Operations
Revenue		71.5		253.0
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale or Disposed of by Sale | Residential Subscription | HSD
Discontinued Operations
Revenue		41.4		143.5
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale or Disposed of by Sale | Residential Subscription | Video
Discontinued Operations
Revenue		27.1		98.6
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale or Disposed of by Sale | Residential Subscription | Telephony
Discontinued Operations
Revenue		3.0		10.9
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale or Disposed of by Sale | Business Subscription
Discontinued Operations
Revenue		8.0		27.1
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale or Disposed of by Sale | Business Subscription | HSD
Discontinued Operations
Revenue		5.0		16.7
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale or Disposed of by Sale | Business Subscription | Video
Discontinued Operations
Revenue		0.7		2.5
Atlantic and Astound broadband markets | Discontinued Operations, Held-for-sale or Disposed of by Sale | Business Subscription | Telephony
Discontinued Operations
Revenue		$ 2.3		$ 7.9