| In millions, except per share items | Jun-30-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 |
| | 10-Q | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q |
| Revenues | | | | | | | | |
| Service fees | 178.0 | -4.2 | -158.5 | -77.2 | 364.7 | 410.5 | 281.8 | 308.6 |
| Service fees growth | -330.5% | -101.0% | -156.3% | -125.0% | 1.6% | 66.1% | 16.0% | -602.5% |
| Carried interest allocations: | | | | | | | | |
| Total revenues | 178.0 | -4.2 | -158.5 | -77.2 | 364.7 | 410.5 | 281.8 | 308.6 |
| Total revenues growth | -330.5% | -101.0% | -156.3% | -125.0% | 1.6% | 66.1% | 16.0% | -602.5% |
| Expenses | | | | | | | | |
| Compensation and benefits: | | | | | | | | |
| Cash-based compensation | 70.1 | 62.6 | 59.5 | 60.1 | 59.3 | 51.7 | 43.9 | 42.7 |
| Equity-based compensation | 8.5 | 8.1 | 3.8 | 3.7 | 3.6 | 3.4 | 3.2 | 3.7 |
| |
| Performance fee-related compensation: | | | | | | | | |
| Realized | 9.1 | 11.7 | 13.6 | 41.7 | 5.1 | 34.0 | 26.8 | 25.3 |
| Unrealized | 24.2 | -31.9 | -86.1 | -54.6 | 84.8 | 68.4 | 74.2 | 85.6 |
| Total performance fee-related compensation | 33.3 | -20.1 | -72.5 | -12.8 | 89.8 | 102.4 | 101.0 | 110.9 |
| Legacy Greenspring performance fee-related compensation | -23.9 | -88.9 | -128.7 | -153.6 | 82.1 | 105.0 | | |
| Total compensation and benefits | 87.9 | -38.3 | -137.9 | -102.7 | 234.9 | 262.4 | 148.1 | 157.3 |
| General, administrative and other | 33.3 | 43.6 | 33.7 | 34.2 | 38.4 | 30.3 | 25.3 | 16.4 |
| Total expenses | 121.2 | -38.3 | -104.2 | -68.4 | 273.3 | 292.7 | 173.4 | 173.7 |
| |
| Other income (expense) | | | | | | | | |
| Investment income (loss) | 3.1 | -0.7 | -3.7 | -1.1 | 5.3 | 7.2 | 7.2 | 6.4 |
| Legacy Greenspring investment loss | -2.9 | | | -8.6 | | | | |
| Investment income of Consolidated Funds | 2.4 | 4.9 | | | | | | |
| Interest income | 0.4 | 0.7 | 0.4 | 0.0 | 0.0 | 0.0 | 0.2 | 0.1 |
| Interest expense | -2.0 | -1.1 | -0.8 | -0.6 | -0.5 | -0.5 | -0.1 | 0.0 |
| Other income (loss) | 0.2 | 0.4 | -0.6 | -1.1 | 4.9 | -0.3 | -2.0 | -0.4 |
| Total other income (expense) | 1.2 | -4.8 | -20.1 | -11.4 | 24.5 | 24.3 | 5.4 | 6.1 |
| Income (loss) before income tax | 58.0 | -14.3 | -74.5 | -20.2 | 115.8 | 142.1 | 113.7 | 140.9 |
| Income tax expense | 8.6 | -0.7 | -7.4 | 1.3 | 12.2 | 15.8 | -14.1 | 14.4 |
| Net income (loss) | 49.4 | -13.6 | -67.1 | -21.5 | 103.6 | 126.3 | 127.9 | 126.5 |
| |
| Less: Net income attributable to non-controlling interests | | | | | | | | |
| Less: Net income attributable to redeemable non-controlling interests in Consolidated Funds | | | | | | | | |
| Net income (loss) attributable to StepStone Group Inc. | 21.3 | -6.9 | -29.2 | -11.0 | 41.8 | 48.3 | 62.1 | 41.7 |
| |
| Net income (loss) per share of Class A common stock: | | | | | | | | |
| Basic (in dollars per share) | $0.34 | ($0.11) | ($0.48) | ($0.18) | $0.60 | $0.84 | $1.49 | $1.07 |
| Diluted (in dollars per share) | $0.34 | ($0.11) | ($0.48) | ($0.18) | $0.62 | $0.83 | $1.45 | $1.06 |
| |
| Weighted-average shares of Class A common stock: | | | | | | | | |
| Basic (in shares) | 62.8 | 62.2 | 61.4 | 61.1 | 49.8 | 57.9 | 41.7 | 39.0 |
| Diluted (in shares) | 65.7 | 62.2 | 61.4 | 61.1 | 53.6 | 61.5 | 45.9 | 42.9 |