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Stock-Based Compensation - Narrative (Details) $ / shares in Units, $ in Thousands | 1 Months Ended | 3 Months Ended | 6 Months Ended
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May 31, 2021 $ / shares | Nov. 30, 2020 $ / shares | May 31, 2020 tranche shares | Jun. 30, 2025 USD ($) $ / shares shares | Sep. 30, 2024 USD ($) $ / shares shares | Jun. 30, 2024 USD ($) $ / shares shares | Jun. 30, 2025 USD ($) $ / shares shares | Jun. 30, 2024 USD ($) $ / shares shares | Jun. 30, 2022 tranche
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Weighted average grant date fair value, grants in period (in usd per share) | $ / shares |  |  |  | $ 30.62 |  | $ 16.85 | $ 27.49 | $ 14.87 |
Stock based compensation not recognized, options |  |  |  | $ 43,700 |  |  | $ 43,700 |  |
Stock based compensation not recognized, period for recognition (in years) |  |  |  |  |  |  | 2 years |  |
Granted (in shares) | shares |  |  |  |  |  |  | 598,729 |  |
Total stock-based compensation expense |  |  |  | 42,462 |  | $ 27,235 | $ 80,219 | $ 54,276 |
Stock options |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Exercises in period, intrinsic value |  |  |  | $ 1,300 |  | $ 8,400 | $ 2,400 | $ 9,000 |
Expected dividend yield |  |  |  | 0.00% |  | 0.00% | 0.00% | 0.00% |
Shares underlying unvested restricted stock units |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Stock based compensation not recognized, period for recognition (in years) |  |  |  |  |  |  | 2 years 2 months 12 days |  |
Stock based compensation not recognized, other than options |  |  |  | $ 215,900 |  |  | $ 215,900 |  |
Performance-based restricted stock units granted |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Weighted average grant date fair value, grants in period (in usd per share) | $ / shares |  | $ 113.40 |  |  | $ 113.40 |  |  |  |
Stock based compensation not recognized, period for recognition (in years) |  |  |  |  |  |  | 2 years 1 month 6 days |  |
Stock based compensation not recognized, other than options |  |  |  | 23,100 |  |  | $ 23,100 |  |
Additional service period requirement |  | 2 years |  |  |  |  |  |  |
Weighted average grant date fair value, vested in period (in usd per share) | $ / shares | $ 148.19 |  |  |  | $ 148.19 |  |  |  |
Cumulative charge |  |  |  |  | $ 24,800 |  |  |  |
Granted (in shares) | shares |  |  |  |  | 219,161 |  |  |  |
Total stock-based compensation expense |  |  |  | 3,600 |  | $ 2,200 | $ 7,800 | $ 3,600 |
Total market-based restricted stock units approved and granted (in shares) | shares |  |  |  |  |  |  | 281,378 |  |
Performance-based restricted stock units granted | Minimum |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Weighted-average derivative service period |  | 1 year |  |  |  |  |  |  |
Market-based stock unit vesting period |  | 1 year |  |  |  |  |  |  |
Performance-based restricted stock units granted | Maximum |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Weighted-average derivative service period |  | 3 years |  |  |  |  |  |  |
Market-based stock unit vesting period |  | 3 years 1 month 6 days |  |  |  |  |  |  |
Phantom Share Units (PSUs) |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Weighted-average derivative service period | 4 years | 4 years |  |  |  |  |  |  |
Market-based stock unit vesting period | 6 months | 6 months |  |  |  |  |  |  |
MSUs |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Number of tranches | tranche |  |  | 3 |  |  |  |  |  | 3
Market-based restricted stock share price goal |  |  | 30 days |  |  |  |  |  |
MSUs | Chief Executive Officer |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Total market-based restricted stock units approved and granted (in shares) | shares |  |  | 1,695,574 |  |  |  |  |  |
Shares available for issuance under the 2018 Employee Stock Purchase Plan |  |  |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |
Stock based compensation not recognized, period for recognition (in years) |  |  |  |  |  |  | 4 months 24 days |  |
Stock based compensation not recognized, other than options |  |  |  | 1,800 |  |  | $ 1,800 |  |
Total stock-based compensation expense |  |  |  | $ 1,200 |  | $ 1,100 | $ 2,800 | $ 2,500 |
Expected dividend yield |  |  |  | 0.00% |  | 0.00% | 0.00% | 0.00% |
Maximum employee subscription rate, ESPP |  |  |  | 10.00% |  |  | 10.00% |  |
Purchase price of common stock (as a percent of the fair value of common stock) |  |  |  |  |  |  | 85.00% |  |
Purchase period |  |  |  |  |  |  | 6 months |  |
Common stock issued under employee stock purchase plan (in shares) | shares |  |  |  | 310,387 |  | 310,387 | 371,826 | 371,826 |

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