Annual report pursuant to Section 13 and 15(d)

Business Combinations and Acquisitions - Narrative (Details)

v3.22.4
Business Combinations and Acquisitions - Narrative (Details) - USD ($)
$ / shares in Units, $ in Millions
1 Months Ended 2 Months Ended 4 Months Ended 6 Months Ended 12 Months Ended
Aug. 01, 2022
Dec. 01, 2021
Oct. 20, 2021
Feb. 28, 2021
Dec. 31, 2021
Oct. 19, 2021
Jun. 30, 2021
Dec. 31, 2022
Jun. 30, 2021
Jun. 30, 2020
Dec. 18, 2020
Business Combination, Separately Recognized Transactions [Line Items]                      
Cash consideration paid by GSAH     $ 1,300.0                
Income tax at U.S. Federal statutory rate         21.00%     21.00%      
CIRS                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Equity interest, acquired percentage   100.00%                  
Goodwill, period increase               $ (1.0)      
Decrease in noncurrent deferred tax assets and liabilities, net               $ 1.0      
CIRS | Medical                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Total consideration transferred   $ 55.1                  
Transaction expenses         $ 0.4            
Intermediate Co                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Cash consideration paid by GSAH     $ 1,300.0                
Business acquisition share price (in dollars per share)     $ 10.00                
Intermediate Co | Class A Common Stock                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Business acquisition equity interest issued or issuable (in shares)     30,401,902                
Intermediate Co | Class B Common Stock                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Business acquisition equity interest issued or issuable (in shares)     8,560,540         8,040,540      
Mirion                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Pro forma adjustments         $ 2.2 $ 26.2          
Income tax at U.S. Federal statutory rate         25.00% 25.00%     25.00%    
Total consideration transferred     $ 2,632.3                
Mirion | Fair Value Adjustment to Inventory                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Pro forma adjustments         $ 15.8 $ 15.8     $ 15.8    
Mirion | Acquisition-related Costs                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Pro forma adjustments         $ 28.4 $ 28.4     28.4    
Critical Infrastructure "CI"                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Equity interest, acquired percentage 100.00%                    
Cash consideration paid by GSAH $ 6.6                    
Goodwill, period increase               $ 3.9      
Decrease in noncurrent deferred tax assets and liabilities, net               4.3      
Decrease in noncontrolling interest               1.8      
Decrease in other noncurrent assets and liabilities, net               $ 1.4      
Total consideration transferred $ 6.5                    
Business acquisition, measurement period 1 year                    
Sun Nuclear                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Equity interest, acquired percentage                     100.00%
Sun Nuclear | Medical                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Cash consideration paid by GSAH       $ 261.9              
Total consideration transferred             $ 276.9        
Transaction expenses             $ 1.2   $ 1.2    
Biodex and SNC                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Income tax at U.S. Federal statutory rate                 25.00% 25.00%  
Biodex and SNC | Fair Value Adjustment to Inventory                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Pro forma adjustments                 $ 5.2 $ 5.2  
Biodex and SNC | Acquisition-related Costs                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Pro forma adjustments                 4.8 4.8  
Biodex and SNC | Reduction In Revenues Due To The Elimination Of Deferred Contract Revenue                      
Business Combination, Separately Recognized Transactions [Line Items]                      
Pro forma adjustments                 $ 14.8 $ 14.8