| In millions, except per share items | Mar-31-23 | Jun-30-22 | Mar-31-22 | Oct-19-21 | Sep-30-21 | Jun-30-21 | Mar-31-21 | Dec-31-20 |
| | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K/A |
| Revenues: | | | | | | | | |
| Total revenues | 182.1 | 175.8 | 163.2 | 168.0 | | 180.0 | 166.2 | |
| Total revenues growth | 11.6% | -2.3% | -1.8% | | | | | |
| Cost of revenues: | | | | | | | | |
| Total cost of revenues | 103.0 | | 98.8 | 97.7 | | | | |
| Gross profit | 79.1 | 79.0 | 64.4 | 70.3 | | 79.6 | 62.5 | |
| Gross margin | 43.4% | 44.9% | 39.5% | 41.8% | | 44.2% | 37.6% | |
| |
| Operating expenses: | | | | | | | | |
| Selling, general and administrative | 85.1 | 91.0 | 90.9 | 101.6 | | 66.7 | 60.4 | |
| Research and development | 7.6 | 7.4 | 7.1 | 10.3 | | 8.2 | 11.0 | |
| Total operating expenses | 92.7 | 153.6 | 98.0 | 111.9 | 2.9 | 74.9 | 71.4 | 2.0 |
| Loss from operations | -13.6 | -74.6 | -33.6 | -41.6 | | 4.7 | -8.9 | |
| Operating margin | -7.5% | -42.4% | -20.6% | -24.8% | | 2.6% | -5.4% | |
| |
| Other expense (income): | | | | | | | | |
| Third party interest expense | 14.9 | 8.4 | 7.9 | 12.5 | | 11.0 | 10.9 | |
| Loss on debt extinguishment | 2.6 | | | 15.9 | | | | |
| Foreign currency (gain) loss, net | -0.3 | 3.3 | 1.5 | -0.6 | | 1.1 | -4.0 | |
| Increase (decrease) in fair value of warrant liabilities | 13.4 | -19.6 | -19.9 | | 1.7 | | | -43.1 |
| Other income, net | -0.2 | | | -1.6 | | 0.5 | 0.2 | |
| Loss before income taxes | -44.0 | -66.7 | -23.1 | -111.3 | -1.2 | -39.6 | -47.8 | -45.1 |
| Benefit from income taxes | -1.1 | -7.4 | -4.1 | -5.6 | -0.1 | 14.4 | -7.1 | -0.2 |
| Net loss | -42.9 | -59.3 | -19.0 | -105.7 | | -54.0 | -40.7 | |
| Loss attributable to noncontrolling interests | -1.0 | -0.7 | -1.3 | | | -0.1 | | |
| Net loss attributable to Mirion Technologies, Inc. | -41.9 | -58.6 | -17.7 | -105.7 | | -53.9 | -40.7 | |
| |
| Net loss per common share attributable to Mirion Technologies, Inc. stockholders — basic | ($0.22) | ($0.32) | ($0.10) | ($15.81) | | ($8.14) | ($6.18) | |
| Net loss per common share attributable to Mirion Technologies, Inc. stockholders — diluted | ($0.22) | ($0.32) | ($0.10) | ($15.81) | | ($8.14) | ($6.18) | |
| |
| Weighted average common shares outstanding — basic (in shares) | 187.7 | 181.0 | 180.8 | 6.7 | 93.8 | 6.6 | 6.6 | 57.0 |
| Weighted average common shares outstanding — diluted (in shares) | 187.7 | 181.0 | 180.8 | 6.7 | | 6.6 | 6.6 | |