v3.26.1
Earnings Per Share - Schedule of Reconciliations of Basic and Diluted Earnings Per Share of Class A Common Stock (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Numerator:      
Net income (loss) attributable to StepStone Group Inc. – Basic $ (535,808) $ (179,563) $ 58,091
Net income (loss) attributable to StepStone Group Inc. – Diluted $ (535,808) $ (179,563) $ 60,744
Denominator:      
Weighted-average shares of Class A common stock outstanding – Basic (in shares) 79,039,229 71,142,916 63,489,135
Weighted-average shares of Class A common stock outstanding - Diluted (in shares) 79,039,229 71,142,916 66,544,038
Net income (loss) per share of Class A common stock:      
Basic (in dollars per share) $ (6.78) $ (2.52) $ 0.91
Diluted (in dollars per share) $ (6.78) $ (2.52) $ 0.91
Restricted Stock Units (RSUs)      
Numerator:      
Incremental income from assumed vesting of units $ 0 $ 0 $ 451
Denominator:      
Assumed vesting of shares (in shares) 0 0 512,152
Class B2 units      
Numerator:      
Incremental income from assumed vesting of units $ 0 $ 0 $ 2,202
Denominator:      
Assumed vesting of shares (in shares) 0 0 2,542,751