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Business Combinations and Acquisitions - Schedule of Business Acquisition, Pro Forma Information (Details) - USD ($) $ in Millions |  |  |  |  | 2 Months Ended | 4 Months Ended | 10 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 01, 2021 | Oct. 20, 2021 | Dec. 18, 2020 | Sep. 01, 2020 | Dec. 31, 2021 | Oct. 19, 2021 | Jun. 30, 2021 | Dec. 31, 2023 | Dec. 31, 2022 | Jun. 30, 2021
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Goodwill |  |  |  |  | $ 1,662.6 |  |  | $ 1,447.6 | $ 1,418.0 |
GAAP purchase consideration, net of cash acquired |  |  |  |  | 58.6 | $ 0.9 |  | $ 31.4 | $ 6.6 | $ 290.1
Interest Rate Swap Cap Agreement |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Other long-term liabilities | $ (9.0) |  |  |  |  |  |  |  |  |
Trade names |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Original Average Life in Years |  | 10 years | 7 years | 7 years |  |  |  |  |  |
Mirion |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total revenues |  |  |  |  | 154.1 | 168.0 |  |  |  | 611.6
Net loss |  |  |  |  | (5.2) | (56.3) |  |  |  | (192.1)
Net loss attributable to Mirion TopCo stockholders |  |  |  |  | $ (3.6) | $ (54.0) |  |  |  | (184.2)
Goodwill |  | $ 1,642.9 |  |  |  |  |  |  |  |
Total amortizable intangible assets |  | 821.0 |  |  |  |  |  |  |  |
Cash |  | 101.9 |  |  |  |  |  |  |  |
Accounts receivable |  | 114.3 |  |  |  |  |  |  |  |
Inventory |  | 144.6 |  |  |  |  |  |  |  |
Property, Plant and Equipment |  | 126.4 |  |  |  |  |  |  |  |
Current lease liability |  | (8.8) |  |  |  |  |  |  |  |
Other long-term liabilities |  | (241.4) |  |  |  |  |  |  |  |
Net tangible assets acquired |  | 168.4 |  |  |  |  |  |  |  |
Purchase consideration |  | (2,632.3) |  |  |  |  |  |  |  |
Less: cash acquired |  | (101.9) |  |  |  |  |  |  |  |
GAAP purchase consideration, net of cash acquired |  | 2,530.4 |  |  |  |  |  |  |  |
Mirion | Developed technology |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets |  | 234.6 |  |  |  |  |  |  |  |
Mirion | Customer relationships |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets |  | 338.8 |  |  |  |  |  |  |  |
Mirion | Trade names |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets |  | 100.5 |  |  |  |  |  |  |  |
Mirion | Backlog and other |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets |  | 81.5 |  |  |  |  |  |  |  |
Mirion | Medical |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Goodwill |  | 680.4 |  |  |  |  |  |  |  |
Total amortizable intangible assets |  | 330.5 |  |  |  |  |  |  |  |
Cash |  | 7.8 |  |  |  |  |  |  |  |
Accounts receivable |  | 44.0 |  |  |  |  |  |  |  |
Inventory |  | 25.1 |  |  |  |  |  |  |  |
Property, Plant and Equipment |  | 52.6 |  |  |  |  |  |  |  |
Current lease liability |  | (4.1) |  |  |  |  |  |  |  |
Other long-term liabilities |  | (70.0) |  |  |  |  |  |  |  |
Net tangible assets acquired |  | 23.2 |  |  |  |  |  |  |  |
Mirion | Medical | Developed technology |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets |  | 66.3 |  |  |  |  |  |  |  |
Mirion | Medical | Customer relationships |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets |  | 152.7 |  |  |  |  |  |  |  |
Mirion | Medical | Trade names |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets |  | 36.8 |  |  |  |  |  |  |  |
Mirion | Medical | Backlog and other |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets |  | $ 17.7 |  |  |  |  |  |  |  |
Biodex and SNC |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total revenues |  |  |  |  |  |  |  |  |  | 670.9
Net loss |  |  |  |  |  |  |  |  |  | (142.9)
Net loss attributable to Mirion TopCo stockholders |  |  |  |  |  |  |  |  |  | $ (127.9)
CIRS | Developed technology |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Original Average Life in Years | 5 years |  |  |  |  |  |  |  |  |
CIRS | Customer relationships |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Original Average Life in Years | 7 years |  |  |  |  |  |  |  |  |
CIRS | Trade names |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Original Average Life in Years | 3 years |  |  |  |  |  |  |  |  |
CIRS | Backlog and other |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Original Average Life in Years | 2 years |  |  |  |  |  |  |  |  |
CIRS | Medical |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Goodwill | $ 34.0 |  |  |  |  |  |  |  |  |
Total amortizable intangible assets | 21.8 |  |  |  |  |  |  |  |  |
Cash | 1.0 |  |  |  |  |  |  |  |  |
Accounts receivable | 1.6 |  |  |  |  |  |  |  |  |
Inventory | 2.0 |  |  |  |  |  |  |  |  |
Property, Plant and Equipment | 0.4 |  |  |  |  |  |  |  |  |
Operating ROU assets | 3.8 |  |  |  |  |  |  |  |  |
Current lease liability | (0.5) |  |  |  |  |  |  |  |  |
Net tangible assets acquired | (1.7) |  |  |  |  |  |  |  |  |
Purchase consideration | (55.1) |  |  |  |  |  |  |  |  |
Less: cash acquired | (1.0) |  |  |  |  |  |  |  |  |
GAAP purchase consideration, net of cash acquired | 54.1 |  |  |  |  |  |  |  |  |
Acquiree revenue post acquisition through the period ended December 31, 2021 | 1.5 |  |  |  |  |  |  |  |  |
Acquiree income (loss) from operations post acquisition through the period ended December 31, 2021 | (0.1) |  |  |  |  |  |  |  |  |
CIRS | Medical | Developed technology |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets | 19.2 |  |  |  |  |  |  |  |  |
CIRS | Medical | Customer relationships |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets | 1.6 |  |  |  |  |  |  |  |  |
CIRS | Medical | Trade names |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets | 0.4 |  |  |  |  |  |  |  |  |
CIRS | Medical | Backlog and other |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets | $ 0.6 |  |  |  |  |  |  |  |  |
Biodex | Medical |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Goodwill |  |  |  | $ 11.1 |  |  |  |  |  |
Total amortizable intangible assets |  |  |  | 6.6 |  |  |  |  |  |
Cash |  |  |  | 4.1 |  |  |  |  |  |
Accounts receivable |  |  |  | 4.0 |  |  |  |  |  |
Inventory |  |  |  | 6.4 |  |  |  |  |  |
Property, Plant and Equipment |  |  |  | 1.0 |  |  |  |  |  |
Other long-term liabilities |  |  |  | 0.0 |  |  |  |  |  |
Net tangible assets acquired |  |  |  | 13.3 |  |  |  |  |  |
Purchase consideration |  |  |  |  |  |  | $ (31.0) |  |  |
Less: cash acquired |  |  |  |  |  |  | (4.1) |  |  |
GAAP purchase consideration, net of cash acquired |  |  |  |  |  |  | 26.9 |  |  |
Acquiree revenue post acquisition through the period ended December 31, 2021 |  |  |  |  |  |  | 32.6 |  |  |
Acquiree income (loss) from operations post acquisition through the period ended December 31, 2021 |  |  |  |  |  |  | $ 0.7 |  |  |
Biodex | Medical | Developed technology |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets |  |  |  | 2.6 |  |  |  |  |  |
Biodex | Medical | Customer relationships |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets |  |  |  | 2.3 |  |  |  |  |  |
Biodex | Medical | Trade names |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |
Total amortizable intangible assets |  |  |  | $ 1.4 |  |  |  |  |  |

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- Definition Amount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer, acquired at the acquisition date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479907/805-20-50-1 + Details
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