Segment Reporting (Revenue by Major Category) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Principal Transaction Revenue [Line Items]
Revenue	$ 5,139.5	$ 5,207.2	$ 5,074.1	$ 4,588.0	$ 4,599.2	$ 4,597.4	$ 4,566.5	$ 4,516.9	$ 20,008.8	$ 18,280.0	$ 18,248.3
Video [Member]
Principal Transaction Revenue [Line Items]
Revenue									6,378.0	6,380.1	6,535.7
Broadband Internet [Member]
Principal Transaction Revenue [Line Items]
Revenue									5,309.4	5,073.4	4,713.6
Fixed-line telephony [Member]
Principal Transaction Revenue [Line Items]
Revenue									3,018.6	3,160.9	3,258.9
Cable Subscription [Member]
Principal Transaction Revenue [Line Items]
Revenue									14,706.0	14,614.4	14,508.2
SOHO Cable Subscription [Member]
Principal Transaction Revenue [Line Items]
Revenue									491.8	319.2	216.5
Mobile Subscription[Member]
Principal Transaction Revenue [Line Items]
Revenue									1,706.4	1,037.3	1,085.6
Mobile Interconnect [Member]
Principal Transaction Revenue [Line Items]
Revenue									313.4	212.7	245.0
Total Subscription [Member]
Principal Transaction Revenue [Line Items]
Revenue									16,412.4	15,651.7	15,593.8
Business to Business [Member]
Principal Transaction Revenue [Line Items]
Revenue									2,156.3	1,580.2	1,515.9
Other [Member]
Principal Transaction Revenue [Line Items]
Revenue									$ 1,440.1	$ 1,048.1	$ 1,138.6