SCHEDULE I (Parent Company Information) CONDENSED STATEMENT OF OPERATIONS (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating costs and expenses:
Selling, general and administrative (including stock-based compensation)			$ 2,218.3	$ 2,107.8	$ 2,049.1
Depreciation and amortization			2,331.3	3,652.2	3,858.2
Other operating expenses			1,777.2	1,641.3	1,717.2
Operating income			2,117.7	745.5	839.1
Non-operating income (expense):
Foreign currency transaction gains (losses), net			(1,416.3)	(94.8)	90.4
Other income, net			76.1	114.4	43.4
Non-operating income (expense)			(3,841.3)	(1,901.5)	(677.3)
Income tax benefit	$ (253.0)	$ (1,573.3)	256.9	(253.0)	(1,573.3)
Net earnings (loss) attributable to Liberty Global shareholders			(1,628.0)	$ 11,521.4	725.3
Liberty Global Plc
Operating costs and expenses:
Selling, general and administrative (including stock-based compensation)	61.0		58.8		42.8
Related-party fees and allocations	20.6		36.0		8.0
Depreciation and amortization	1.4		1.4		1.5
Other operating expenses	0.2		0.0		0.0
Operating income	(83.2)		(96.2)		(52.3)
Non-operating income (expense):
Interest expense — related-party	(864.6)		(1,086.9)		(678.0)
Interest income — related-party	89.6		45.1		70.9
Foreign currency transaction gains (losses), net	281.2		(330.2)		381.0
Other income, net	3.4		2.1		0.1
Non-operating income (expense)	(490.4)		(1,369.9)		(226.0)
Loss before income taxes and equity in earnings (losses) of consolidated subsidiaries, net	(573.6)		(1,466.1)		(278.3)
Equity in earnings (losses) of consolidated subsidiaries, net	11,921.4		(401.0)		887.9
Income tax benefit	173.6		239.1		115.7
Net earnings (loss) attributable to Liberty Global shareholders	$ 11,521.4		$ (1,628.0)		$ 725.3