Acquisitions (Proforma Information Schedule and Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2018 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Business Acquisition [Line Items] | |||||||||||
| Revenue | $ 2,949.1 | $ 2,929.7 | $ 3,015.6 | $ 3,063.5 | $ 2,987.8 | $ 2,899.3 | $ 2,746.8 | $ 2,642.5 | $ 11,957.9 | $ 11,276.4 | $ 13,731.1 |
| Net earnings (loss) | $ 25.1 | $ 974.1 | $ 912.6 | $ (1,186.5) | $ (992.0) | $ (791.6) | $ (674.3) | $ (320.2) | $ 725.3 | $ (2,778.1) | 1,705.3 |
| BASE | |||||||||||
| Business Acquisition [Line Items] | |||||||||||
| Revenue | 597.1 | ||||||||||
| Net earnings (loss) | (2.1) | ||||||||||
| Liberty Global Shares | BASE | |||||||||||
| Business Acquisition [Line Items] | |||||||||||
| Revenue | 13,805.5 | ||||||||||
| Net earnings (loss) from continuing operations attributable to Liberty Global shareholders: | $ 1,621.0 | ||||||||||
| Basic (in dollars per share) | $ 1.82 | ||||||||||
| Diluted (in dollars per share) | $ 1.80 | ||||||||||