Mirion Technologies, Inc. Post-effective amendment to a registration statement that is not immediately effective upon filing

Post-effective amendment to a registration statement that is not immediately effective upon filing

Loss Per Share - Reconciliation of Numerator and Denominator (Details)

Loss Per Share - Reconciliation of Numerator and Denominator (Details) - USD ($) $ / shares in Units, $ in Millions	2 Months Ended	4 Months Ended	12 Months Ended
	Dec. 31, 2021	Oct. 19, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net loss attributable to Mirion Technologies, Inc. (Successor) / Mirion Technologies (TopCo), Ltd. (Predecessor) shareholders	$ (22.2)	$ (105.7)	$ (158.3)	$ (119.1)	$ (122.0)
Weighted average common shares outstanding — basic (in shares)	180.773	6.685	6.549	6.453	6.300
Weighted average common shares outstanding — diluted (in shares)	180.773	6.685	6.549	6.453	6.300
Net loss per common share attributable to Mirion Technologies, Inc. (Successor) / Mirion Technologies (TopCo), Ltd. (Predecessor) stockholders — basic (in dollars per share)	$ 0.12	$ 15.81	$ 24.18	$ 18.45	$ 19.36
Net loss per common share attributable to Mirion Technologies, Inc. (Successor) / Mirion Technologies (TopCo), Ltd. (Predecessor) stockholders — diluted (in dollars per share)	$ 0.12	$ 15.81	$ 24.18	$ 18.45	$ 19.36
Anti-dilutive employee share-based awards, excluded	0	0	0	0	0
Share-based awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Anti-dilutive employee share-based awards, excluded	0.003	0.200	0.300	0.400	0.500

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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