v3.10.0.1
Segment Reporting (Revenue by Major Category) (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Segment Reporting Information [Line Items]        
Revenue $ 3,045.1 $ 2,774.9 $ 6,139.6 $ 5,444.7
Total residential cable revenue        
Segment Reporting Information [Line Items]        
Revenue 2,040.3 1,914.9 4,159.8 3,782.3
Total subscription revenue        
Segment Reporting Information [Line Items]        
Revenue 1,967.9 1,838.0 4,005.7 3,624.5
Video        
Segment Reporting Information [Line Items]        
Revenue 743.5 717.3 1,518.1 1,406.2
Broadband internet        
Segment Reporting Information [Line Items]        
Revenue 816.7 724.8 1,657.9 1,430.7
Fixed-line telephony        
Segment Reporting Information [Line Items]        
Revenue 407.7 395.9 829.7 787.6
Non-subscription revenue        
Segment Reporting Information [Line Items]        
Revenue 72.4 76.9 154.1 157.8
Total residential revenue        
Segment Reporting Information [Line Items]        
Revenue 2,465.1 2,295.0 5,007.9 4,525.3
Subscription revenue        
Segment Reporting Information [Line Items]        
Revenue 249.6 245.8 493.4 482.1
Non-subscription revenue        
Segment Reporting Information [Line Items]        
Revenue 175.2 134.3 354.7 260.9
Total residential mobile revenue        
Segment Reporting Information [Line Items]        
Revenue 424.8 380.1 848.1 743.0
Total B2B revenue        
Segment Reporting Information [Line Items]        
Revenue 503.1 429.1 991.0 821.2
Subscription revenue        
Segment Reporting Information [Line Items]        
Revenue 102.9 91.2 219.6 168.5
Non-subscription revenue        
Segment Reporting Information [Line Items]        
Revenue 400.2 337.9 771.4 652.7
Other revenue        
Segment Reporting Information [Line Items]        
Revenue $ 76.9 $ 50.8 $ 140.7 $ 98.2