SCHEDULE I (Parent Company Information) CONDENSED STATEMENT OF OPERATIONS (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating costs and expenses:
Selling, general and administrative (including stock-based compensation)									$ 2,049.1	$ 1,980.4	$ 2,494.6
Depreciation and amortization									3,858.2	3,790.6	4,117.7
Other operating expenses									1,717.2	1,659.5	1,924.8
Operating income	$ 252.4	$ 205.1	$ 264.1	$ 117.5	$ 153.1	$ 218.8	$ 206.3	$ 214.2	839.1	792.4	1,570.1
Non-operating income (expense):
Foreign currency transaction gains (losses), net									90.4	(181.5)	(326.3)
Other income, net									43.4	46.4	124.0
Non-operating income (expense)									(677.3)	(2,903.5)	(1,326.8)
Income tax expense (benefit)									(1,573.3)	(238.9)	1,407.0
Net earnings (loss) attributable to Liberty Global shareholders	$ 25.1	$ 974.1	$ 912.6	$ (1,186.5)	$ (992.0)	$ (791.6)	$ (674.3)	$ (320.2)	725.3	(2,778.1)	1,705.3
Liberty Global Plc
Operating costs and expenses:
Selling, general and administrative (including stock-based compensation)									42.8	44.9	52.9
Related-party fees and allocations									8.0	55.2	66.3
Depreciation and amortization									1.5	1.0	0.8
Other operating expenses									0.0	0.0	0.7
Operating income									(52.3)	(101.1)	(120.7)
Non-operating income (expense):
Interest expense — related-party									(678.0)	(406.5)	(162.3)
Interest income — related-party									70.9	822.7	781.0
Foreign currency transaction gains (losses), net									381.0	(644.8)	45.8
Other income, net									0.1	(3.3)	(1.3)
Non-operating income (expense)									(226.0)	(231.9)	663.2
Earnings before income taxes and equity in earnings (losses) of consolidated subsidiaries, net									(278.3)	(333.0)	542.5
Equity in earnings (losses) of consolidated subsidiaries, net									887.9	(2,386.0)	1,279.7
Income tax expense (benefit)									115.7	(59.1)	(116.9)
Net earnings (loss) attributable to Liberty Global shareholders									$ 725.3	$ (2,778.1)	$ 1,705.3