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Stockholders' Equity - Narrative (Details) $ / shares in Units, $ in Thousands |  | 1 Months Ended | 6 Months Ended
--- | --- | --- | ---
Aug. 10, 2021 $ / shares | Sep. 30, 2021 classOfStock $ / shares shares | Jun. 30, 2021 shares | Mar. 31, 2021 $ / shares shares | Jun. 30, 2020 USD ($) | Sep. 30, 2021 USD ($) classOfStock $ / shares shares | Sep. 30, 2020 USD ($)
Equity [Abstract] |  |  |  |  |  |  |
Number of classes of common stock outstanding | classOfStock |  | 2 |  |  |  | 2 |
Preferred stock, shares authorized (in shares) |  | 25,000,000 |  |  |  | 25,000,000 |
Preferred stock, par value (in dollars per share) | $ / shares |  | $ 0.001 |  |  |  | $ 0.001 |
Preferred stock, shares issued (in shares) |  | 0 |  |  |  | 0 |
Preferred stock, shares outstanding (in shares) |  | 0 |  |  |  | 0 |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Purchase of non-controlling interests | $ |  |  |  |  |  | $ 3,046 | $ 131,294
Sale of partnership interests | $ |  |  |  |  |  | $ 0 | $ 3,308
Dividend (in dollars per share) | $ / shares | $ 0.07 |  |  |  |  |  |
SRA |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Purchase of non-controlling interests | $ |  |  |  |  | $ 3,300 |  |
Sale of partnership interests | $ |  |  |  |  | $ 3,300 |  |
Public offering |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Shares sold in offering (in shares) |  |  |  | 9,200,000 |  |  |
Offering price per share (in dollars per share) | $ / shares |  |  |  | $ 29.50 |  |  |
Underwriters' option |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Shares sold in offering (in shares) |  |  |  | 1,200,000 |  |  |
Class A Common Stock |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Share exchange, shares issued (in shares) |  | 2,087,281 | 1,898,438 | 9,200,000 |  |  |
Class A Common Stock | Greenspring |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Stock issued for acquisition (in shares) |  | 12,686,756 |  |  |  |  |
Class C units |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Conversion basis (in shares) |  |  |  |  |  | 1 |
Class C units | Greenspring |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Stock issued for acquisition (in shares) |  | 3,071,519 |  |  |  |  |
Class B Common Stock |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Share exchange, shares exchanged (in shares) |  | 2,087,281 | 1,898,438 | 9,200,000 |  |  |
SRA |  |  |  |  |  |  |
Subsidiary, Sale of Stock [Line Items] |  |  |  |  |  |  |
Noncontrolling interest, ownership by parent |  | 49.00% |  |  |  | 49.00% |
Noncontrolling interest, ownership by noncontrolling owners |  | 51.00% |  |  |  | 51.00% |

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