Schedule I - Condensed Financial Information of the Registrant - CONDENSED BALANCE SHEET (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Assets:
Cash and cash equivalents	$ 412.3	$ 175.2	$ 128.8
Prepaid expenses and other current assets	53.4	41.6
Total Assets	3,588.1	2,636.0
Liabilities and Stockholders’ Equity:
Accrued expenses and other current liabilities	116.4	99.3
Convertible debt	754.5	0.0
Total liabilities	1,671.2	1,076.9
Treasury stock	(58.4)	(3.2)
Additional paid-in capital	2,490.1	2,143.3
Accumulated deficit	(512.7)	(541.5)
Accumulated other comprehensive loss	(52.6)	(93.0)
Mirion Technologies, Inc. stockholders’ equity	1,866.4	1,505.6
Noncontrolling interests	50.5	53.5
Total Stockholders’ Equity	1,916.9	1,559.1	$ 1,550.0	$ 1,467.2
Total Liabilities and Stockholders’ Equity	3,588.1	2,636.0
Parent Company
Assets:
Cash and cash equivalents	0.2	0.0
Prepaid expenses and other current assets	3.2	0.0
Investments in subsidiaries	2,660.1	1,558.8
Total Assets	2,663.5	1,558.8
Liabilities and Stockholders’ Equity:
Accrued expenses and other current liabilities	4.0	0.2
Convertible debt	754.5	0.0
Deferred income taxes and other liabilities	(11.9)	(0.5)
Total liabilities	746.6	(0.3)
Treasury stock	(58.4)	(3.2)
Additional paid-in capital	2,490.1	2,143.3
Accumulated deficit	(512.7)	(541.5)
Accumulated other comprehensive loss	(52.6)	(93.0)
Mirion Technologies, Inc. stockholders’ equity	1,866.4	1,505.6
Noncontrolling interests	50.5	53.5
Total Stockholders’ Equity	1,916.9	1,559.1
Total Liabilities and Stockholders’ Equity	$ 2,663.5	$ 1,558.8