Long-lived Assets - Schedule of Goodwill (Details) $ in Millions	9 Months Ended
Sep. 30, 2026 USD ($)
Goodwill [Roll Forward]
Goodwill. beginning balance	$ 3,007.5
Foreign currency translation adjustments	51.8
Goodwill. ending balance	3,059.3
Liberty Caribbean
Goodwill [Roll Forward]
Goodwill. beginning balance	1,207.9
Foreign currency translation adjustments	0.2
Goodwill. ending balance	1,208.1
C&W Panama
Goodwill [Roll Forward]
Goodwill. beginning balance	617.1
Foreign currency translation adjustments	0.0
Goodwill. ending balance	617.1
Liberty Networks
Goodwill [Roll Forward]
Goodwill. beginning balance	669.3
Foreign currency translation adjustments	4.3
Goodwill. ending balance	673.6
Liberty Costa Rica
Goodwill [Roll Forward]
Goodwill. beginning balance	513.2
Foreign currency translation adjustments	47.3
Goodwill. ending balance	$ 560.5

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