Acquisitions and Dispositions (Schedules) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Operating results of discontinued operations
Net earnings (loss)	$ 322.6	$ 188.6
Basic earnings (loss) from discontinued operations attributable to Liberty Global shareholders per Liberty Global Share (in dollars per share)	$ 0.43	$ 0.23
Discontinued Operations
Operating results of discontinued operations
Revenue		$ 1,092.6
Operating income (loss)		375.5
Earnings (loss) before income taxes		244.7
Income tax benefit (expense)		(56.1)
Net earnings (loss)		188.6
Net loss (earnings) attributable to noncontrolling interests		(1.8)
Net earnings (loss) attributable to Liberty Global shareholders		186.8
Discontinued Operations, Disposed of by Sale
Assets:
Current assets other than cash	$ 412.1		$ 356.5
Property and equipment, net	5,769.5		5,671.1
Goodwill	3,903.5		3,986.7
Other assets, net	886.5		516.8
Total assets	10,971.6		10,531.1
Liabilities:
Current portion of debt and finance lease obligations	860.7		820.2
Other accrued and current liabilities	1,221.7		1,147.3
Long-term debt and finance lease obligations	8,954.2		9,074.6
Other long-term liabilities	1,364.1		997.8
Total liabilities	12,400.7		12,039.9
Operating results of discontinued operations
Revenue	886.4
Operating income (loss)	504.1
Earnings (loss) before income taxes	439.4
Income tax benefit (expense)	(116.8)
Net earnings (loss)	322.6
Net earnings (loss) attributable to Liberty Global shareholders	322.6
UPC Austria | Discontinued Operations, Disposed of by Sale
Operating results of discontinued operations
Revenue		109.4
Operating income (loss)		61.2
Earnings (loss) before income taxes		61.1
Income tax benefit (expense)		(9.5)
Net earnings (loss)		51.6
Net loss (earnings) attributable to noncontrolling interests		(1.8)
Net earnings (loss) attributable to Liberty Global shareholders		49.8
Vodafone Disposal Group | Discontinued Operations, Disposed of by Sale
Assets:
Current assets other than cash	404.3		348.0
Property and equipment, net	5,688.6		5,591.4
Goodwill	3,903.5		3,986.7
Other assets, net	879.3		509.4
Total assets	10,875.7		10,435.5
Liabilities:
Current portion of debt and finance lease obligations	848.5		809.0
Other accrued and current liabilities	1,190.1		1,114.8
Long-term debt and finance lease obligations	8,919.1		9,037.1
Other long-term liabilities	1,363.8		997.5
Total liabilities	12,321.5		11,958.4
Operating results of discontinued operations
Revenue	858.7	952.2
Operating income (loss)	495.5	311.5
Earnings (loss) before income taxes	432.1	181.5
Income tax benefit (expense)	(116.8)	(46.6)
Net earnings (loss)	315.3	134.9
Net loss (earnings) attributable to noncontrolling interests		0.0
Net earnings (loss) attributable to Liberty Global shareholders	315.3	134.9
UPC DTH | Discontinued Operations, Disposed of by Sale
Assets:
Current assets other than cash	7.8		8.5
Property and equipment, net	80.9		79.7
Goodwill	0.0		0.0
Other assets, net	7.2		7.4
Total assets	95.9		95.6
Liabilities:
Current portion of debt and finance lease obligations	12.2		11.2
Other accrued and current liabilities	31.6		32.5
Long-term debt and finance lease obligations	35.1		37.5
Other long-term liabilities	0.3		0.3
Total liabilities	79.2		$ 81.5
Operating results of discontinued operations
Revenue	27.7	31.0
Operating income (loss)	8.6	2.8
Earnings (loss) before income taxes	7.3	2.1
Income tax benefit (expense)	0.0	0.0
Net earnings (loss)	7.3	2.1
Net loss (earnings) attributable to noncontrolling interests		0.0
Net earnings (loss) attributable to Liberty Global shareholders	$ 7.3	$ 2.1