Schedule I - Condensed Financial Information of the Registrant - CONDENSED STATEMENT OF OPERATIONS AND COMPREHENSIVE LOSS INCOME (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Operating expenses:
Selling, general and administrative	$ 348.2	$ 341.1	$ 340.1
Total operating expenses	387.1	374.9	378.3
Loss from operations	51.5	24.8	(21.9)
Other expense (income):
Increase in fair values of warrant liabilities	0.0	5.3	24.8
Interest expense	42.2	57.9	61.9
Other (income) expense, net	0.3	(0.1)	(0.8)
Income (loss) before income taxes	32.7	(33.9)	(105.3)
Income tax (benefit) expense	2.9	2.7	(6.6)
Net income (loss)	29.8	(36.6)	(98.7)
Income (loss) attributable to noncontrolling interests	1.0	(0.5)	(1.8)
Net income (loss) attributable to Mirion Technologies, Inc. stockholders	28.8	(36.1)	(96.9)
Foreign currency translation (loss) gain, net of tax	68.5	(41.2)	18.8
Other comprehensive income (loss), net of tax	41.7	(28.6)	10.8
Comprehensive income (loss) attributable to Mirion Technologies, Inc. stockholders	$ 69.2	$ (63.8)	$ (86.5)
Earnings (loss) per common share attributable to Mirion Technologies, Inc.:
Basic (in dollars per share)	$ 0.13	$ (0.18)	$ (0.49)
Diluted (in dollars per share)	$ 0.11	$ (0.18)	$ (0.49)
Weighted average common shares outstanding:
Basic (in shares)	229,959	204,991	196,369
Diluted (in shares)	261,154	204,991	196,369
Parent Company
Operating expenses:
Selling, general and administrative	$ 19.0	$ 16.6	$ 22.5
Total operating expenses	19.0	16.6	22.5
Loss from operations	(19.0)	(16.6)	(22.5)
Other expense (income):
Increase in fair values of warrant liabilities	0.0	5.3	24.8
Equity in net (income) loss of subsidiaries	(37.9)	14.3	51.1
Interest expense	2.5	0.0	0.0
Other (income) expense, net	(0.2)	0.0	0.3
Income (loss) before income taxes	16.6	(36.2)	(98.7)
Income tax (benefit) expense	(13.2)	0.4	0.0
Net income (loss)	29.8	(36.6)	(98.7)
Income (loss) attributable to noncontrolling interests	1.0	(0.5)	(1.8)
Net income (loss) attributable to Mirion Technologies, Inc. stockholders	28.8	(36.1)	(96.9)
Foreign currency translation (loss) gain, net of tax	0.0	0.0	(0.3)
Other comprehensive income (loss), net of tax	0.0	0.0	(0.3)
Comprehensive income (loss) attributable to Mirion Technologies, Inc. stockholders	$ 28.8	$ (36.1)	$ (97.2)
Earnings (loss) per common share attributable to Mirion Technologies, Inc.:
Basic (in dollars per share)	$ 0.13	$ (0.18)	$ (0.49)
Diluted (in dollars per share)	$ 0.11	$ (0.18)	$ (0.49)
Weighted average common shares outstanding:
Diluted (in shares)	261,154	204,991	196,369