Condensed Consolidated Statements of Comprehensive Loss (unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (779.0)	$ (205.1)	$ (1,698.6)	$ (468.7)
Other comprehensive earnings (loss), net of taxes:
Foreign currency translation adjustments	548.6	(177.7)	1,659.5	(1,171.9)
Pension-related adjustments and other	(7.9)	(35.9)	(8.4)	(41.1)
Other comprehensive earnings (loss)	540.7	(213.6)	1,651.1	(1,213.0)
Comprehensive loss	(238.3)	(418.7)	(47.5)	(1,681.7)
Comprehensive earnings attributable to noncontrolling interests	(12.6)	(44.6)	(87.1)	(48.1)
Comprehensive loss attributable to Liberty Global shareholders	$ (250.9)	$ (463.3)	$ (134.6)	$ (1,729.8)