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Acquisitions - Summary of Unaudited Pro Forma Financial Information (Detail)

v3.21.2
Acquisitions - Summary of Unaudited Pro Forma Financial Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Business Acquisition, Pro Forma Information [Abstract]    
Total revenues $ 670.9 $ 598.7
Net loss (168.5) (151.9)
Net loss attributable to Mirion Technologies (TopCo), Ltd stockholders $ (168.4) $ (151.9)