Revenue from Contracts with Customers - Unsatisfied Performance Obligations Amount (Details) $ in Millions	Sep. 30, 2023 USD ($)
Business subscription services and other business services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 104.6
Business subscription services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	99.9
Other business services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 4.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01 | Residential Subscription | Maximum
Unsatisfied Performance Obligations
Expected period to recognize revenue of remaining performance obligations	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01 | Business subscription services and other business services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 16.6
Expected period to recognize revenue of remaining performance obligations	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01 | Business subscription services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 15.8
Expected period to recognize revenue of remaining performance obligations	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01 | Other business services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 0.8
Expected period to recognize revenue of remaining performance obligations	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Business subscription services and other business services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 49.4
Expected period to recognize revenue of remaining performance obligations	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Business subscription services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 46.9
Expected period to recognize revenue of remaining performance obligations	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Other business services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 2.5
Expected period to recognize revenue of remaining performance obligations	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | Business subscription services and other business services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 27.2
Expected period to recognize revenue of remaining performance obligations	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | Business subscription services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 26.2
Expected period to recognize revenue of remaining performance obligations	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | Other business services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 1.0
Expected period to recognize revenue of remaining performance obligations	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Business subscription services and other business services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 11.4
Expected period to recognize revenue of remaining performance obligations
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Business subscription services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 11.0
Expected period to recognize revenue of remaining performance obligations
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Other business services
Unsatisfied Performance Obligations
Expected revenue to be recognized in future periods	$ 0.4
Expected period to recognize revenue of remaining performance obligations