SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS (Details) - Allowance for doubtful accounts — Trade receivables (Continuing operations) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of period	$ 74.2	$ 56.1	$ 60.8
Impact of the adoption of ASU 2014-09	11.9	0.0	0.0
Additions to costs and expenses	61.6	51.6	50.9
Acquisitions	0.0	1.5	3.8
VodafoneZiggo JV Transaction	0.0	0.0	(13.0)
Deductions or write-offs	(98.4)	(41.7)	(39.3)
Foreign currency translation adjustments	(3.5)	6.7	(7.1)
Balance at end of period	$ 45.8	$ 74.2	$ 56.1