Condensed Consolidated Statements of Equity (unaudited) - USD ($) $ in Millions	Total	Total Liberty Global shareholders	Ordinary shares Class A	Ordinary shares Class B	Ordinary shares Class C	Additional paid-in capital	Accumulated earnings	Accumulated other comprehensive earnings, net of taxes	Treasury shares, at cost	Non-controlling interests	Adjustment	Adjustment Total Liberty Global shareholders	Adjustment Accumulated earnings	Adjustment Non-controlling interests	Adjusted balance	Adjusted balance Total Liberty Global shareholders	Adjusted balance Ordinary shares Class A	Adjusted balance Ordinary shares Class B	Adjusted balance Ordinary shares Class C	Adjusted balance Additional paid-in capital	Adjusted balance Accumulated earnings	Adjusted balance Accumulated other comprehensive earnings, net of taxes	Adjusted balance Treasury shares, at cost	Adjusted balance Non-controlling interests
Balance, before effect of accounting change at Dec. 31, 2018	$ 4,148.3	$ 4,681.4	$ 2.0	$ 0.1	$ 5.3	$ 9,214.5	$ (5,172.2)	$ 631.8	$ (0.1)	$ (533.1)	$ 1.2	$ 1.2	$ 1.2		$ 4,149.5	$ 4,682.6	$ 2.0	$ 0.1	$ 5.3	$ 9,214.5	$ (5,171.0)	$ 631.8	$ (0.1)	$ (533.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	15.7	7.0					7.0			8.7
Other comprehensive loss, net of taxes	(135.0)	(135.2)						(135.2)		0.2
Repurchases and cancellations of Liberty Global ordinary shares	(214.1)	(214.1)			(0.1)	(214.0)
Repurchases by Telenet of its outstanding shares	(56.9)	(68.2)				(68.2)				11.3
Share-based compensation (note 13)	55.6	55.6				55.6
Adjustments due to changes in subsidiaries’ equity and other, net	34.8	32.4				32.4				2.4
Balance at Mar. 31, 2019	3,849.6	4,360.1	2.0	0.1	5.2	9,020.3	(5,164.0)	496.6	(0.1)	(510.5)
Balance, before effect of accounting change at Dec. 31, 2018	4,148.3	4,681.4	2.0	0.1	5.3	9,214.5	(5,172.2)	631.8	(0.1)	(533.1)	1.2	1.2	1.2		4,149.5	4,682.6	2.0	0.1	5.3	9,214.5	(5,171.0)	631.8	(0.1)	(533.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	12,983.3
Other comprehensive loss, net of taxes	(681.3)
Balance at Sep. 30, 2019	13,361.6	13,787.3	1.8	0.1	4.4	6,094.1	7,736.9	(49.9)	(0.1)	(425.7)
Balance, before effect of accounting change at Dec. 31, 2018	4,148.3	4,681.4	2.0	0.1	5.3	9,214.5	(5,172.2)	631.8	(0.1)	(533.1)	1.2	1.2	1.2		4,149.5	4,682.6	2.0	0.1	5.3	9,214.5	(5,171.0)	631.8	(0.1)	(533.1)
Balance at Dec. 31, 2019	$ 13,198.6	13,606.2	1.8	0.1	4.4	6,136.9	6,350.4	1,112.7	(0.1)	(407.6)	(30.1)	(30.3)	(30.3)	$ 0.2	13,168.5	13,575.9	1.8	0.1	4.4	6,136.9	6,320.1	1,112.7	(0.1)	(407.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting standards update	us-gaap:AccountingStandardsUpdate201613Member
Balance, before effect of accounting change at Mar. 31, 2019	$ 3,849.6	4,360.1	2.0	0.1	5.2	9,020.3	(5,164.0)	496.6	(0.1)	(510.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	82.5	53.0					53.0			29.5
Other comprehensive loss, net of taxes	(6.3)	(6.5)						(6.5)		0.2
Repurchases and cancellations of Liberty Global ordinary shares	(288.4)	(288.4)			(0.1)	(288.3)
Repurchases by Telenet of its outstanding shares	(57.2)	(66.3)				(66.3)				9.1
Share-based compensation (note 13)	70.0	70.0				70.0
Adjustments due to changes in subsidiaries’ equity and other, net	20.5	11.6				11.6				8.9
Balance at Jun. 30, 2019	3,670.7	4,133.5	2.0	0.1	5.1	8,747.3	(5,111.0)	490.1	(0.1)	(462.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	12,885.1	12,847.9					12,847.9			37.2
Other comprehensive loss, net of taxes	(540.0)	(540.0)						(540.0)
Repurchases and cancellations of Liberty Global ordinary shares	(2,715.8)	(2,715.8)	(0.2)		(0.7)	(2,714.9)
Share-based compensation (note 13)	61.7	61.7				61.7
Adjustments due to changes in subsidiaries’ equity and other, net	(0.1)	0.0								(0.1)
Balance at Sep. 30, 2019	13,361.6	13,787.3	1.8	0.1	4.4	6,094.1	7,736.9	(49.9)	(0.1)	(425.7)
Balance, before effect of accounting change at Dec. 31, 2019	13,198.6	13,606.2	1.8	0.1	4.4	6,136.9	6,350.4	1,112.7	(0.1)	(407.6)	(30.1)	(30.3)	(30.3)	0.2	13,168.5	13,575.9	1.8	0.1	4.4	6,136.9	6,320.1	1,112.7	(0.1)	(407.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	1,017.7	949.8					949.8			67.9
Other comprehensive loss, net of taxes	(1,073.2)	(1,072.5)						(1,072.5)		(0.7)
Repurchases and cancellations of Liberty Global ordinary shares	(224.4)	(224.4)			(0.1)	(224.3)
Repurchases by Telenet of its outstanding shares	(38.1)	(45.3)				(45.3)				7.2
Share-based compensation (note 13)	46.1	46.1				46.1
Adjustments due to changes in subsidiaries’ equity and other, net	15.6	14.5				14.5				1.1
Balance at Mar. 31, 2020	12,912.2	13,244.1	1.8	0.1	4.3	5,927.9	7,269.9	40.2	(0.1)	(331.9)
Balance, before effect of accounting change at Dec. 31, 2019	13,198.6	13,606.2	1.8	0.1	4.4	6,136.9	6,350.4	1,112.7	(0.1)	(407.6)	$ (30.1)	$ (30.3)	$ (30.3)	$ 0.2	$ 13,168.5	$ 13,575.9	$ 1.8	$ 0.1	$ 4.4	$ 6,136.9	$ 6,320.1	$ 1,112.7	$ (0.1)	$ (407.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	(459.7)
Other comprehensive loss, net of taxes	935.8
Balance at Sep. 30, 2020	12,765.0	13,095.7	1.8	0.1	3.9	5,312.2	5,722.6	2,055.2	(0.1)	(330.7)
Balance, before effect of accounting change at Mar. 31, 2020	12,912.2	13,244.1	1.8	0.1	4.3	5,927.9	7,269.9	40.2	(0.1)	(331.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	(503.8)	(524.2)					(524.2)			20.4
Other comprehensive loss, net of taxes	630.6	636.6						636.6		(6.0)
Repurchases and cancellations of Liberty Global ordinary shares	(475.8)	(475.8)			(0.3)	(475.5)
Share-based compensation (note 13)	69.5	69.5				69.5
Adjustments due to changes in subsidiaries’ equity and other, net	(82.2)	(16.2)				(16.2)				(66.0)
Balance at Jun. 30, 2020	12,550.5	12,934.0	1.8	0.1	4.0	5,505.7	6,745.7	676.8	(0.1)	(383.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	(973.6)	(1,023.1)					(1,023.1)			49.5
Other comprehensive loss, net of taxes	1,378.4	1,378.4						1,378.4
Repurchases and cancellations of Liberty Global ordinary shares	(279.0)	(279.0)			(0.1)	(278.9)
Share-based compensation (note 13)	84.8	84.8				84.8
Adjustments due to changes in subsidiaries’ equity and other, net	3.9	0.6				0.6				3.3
Balance at Sep. 30, 2020	$ 12,765.0	$ 13,095.7	$ 1.8	$ 0.1	$ 3.9	$ 5,312.2	$ 5,722.6	$ 2,055.2	$ (0.1)	$ (330.7)