Long-lived Assets (Changes in Carrying Amount of Goodwill) (Details) - 9 months ended Sep. 30, 2026 $ in Millions, € in Billions	USD ($)	EUR (€)
Goodwill [Roll Forward]
Goodwill beginning balance	$ 3,502.8
Reallocation	0.0
Acquisitions and related adjustments	4,172.0
Foreign currency translation adjustments and other	(176.4)
Goodwill ending balance	7,498.4
Ziggo Group
Goodwill [Roll Forward]
Goodwill beginning balance	2,516.5
Reallocation	(1,485.3)
Acquisitions and related adjustments	4,169.4
Foreign currency translation adjustments and other	(138.5)
Goodwill ending balance	5,062.1
Wyre
Goodwill [Roll Forward]
Goodwill beginning balance	457.0
Reallocation	1,485.3	€ 1.3
Acquisitions and related adjustments	0.0
Foreign currency translation adjustments and other	(26.2)
Goodwill ending balance	1,916.1
VM Ireland
Goodwill [Roll Forward]
Goodwill beginning balance	284.4
Reallocation	0.0
Acquisitions and related adjustments	0.0
Foreign currency translation adjustments and other	(9.6)
Goodwill ending balance	274.8
Other
Goodwill [Roll Forward]
Goodwill beginning balance	244.9
Reallocation	0.0
Acquisitions and related adjustments	2.6
Foreign currency translation adjustments and other	(2.1)
Goodwill ending balance	$ 245.4

Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

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+ Details