| Pay vs Performance Disclosure number in Millions | 12 Months Ended |
| Mar. 31, 2023 USD ($) | Mar. 31, 2022 USD ($) | Mar. 31, 2021 USD ($) |
| Pay vs Performance Disclosure | | | |
| Pay vs Performance Disclosure, Table | Fiscal 2023 Pay Versus Performance Table Fiscal Year Summary Compensation Table Total for PEO ($)(1)(2) Compensation Actually Paid to PEO ($)(4) Average Summary Compensation Table Total for Non-PEO Named Executive Officers ($)(1)(2) Average Compensation Actually Paid to Non-PEO Named Executive Officers Value of Initial Fixed $100 Investment Based on Net Income ($)(in millions) Revenue ($)(in millions) Total Shareholder Return ($) Peer Group Total Shareholder Return ($)(3) 2023 7,000,000 7,003,642 4,587,500 4,594,878 172 165 254 1,809 2022 10,650,000 11,538,558 10,162,500 10,946,169 172 192 438 2,270 2021 6,900,000 7,612,667 6,712,500 7,297,584 130 167 313 1,525 | | |
| Company Selected Measure Name | Revenue | | |
| Named Executive Officers, Footnote | Scott Beiser has served as the Company’s Chief Executive Officer since 2003 and is the Principal Executive Officer (“PEO”) of the Company. The other Named Executive Officers for each fiscal year were Messrs. Alley, Gold, Adelson and Preiser. | | |
| Peer Group Issuers, Footnote | For the relevant fiscal year, represents the cumulative TSR of the S&P 500 Financials Index (“the Peer Group TSR”). | | |
| PEO Total Compensation Amount | $ 7,000,000 | $ 10,650,000 | $ 6,900,000 |
| PEO Actually Paid Compensation Amount | $ 7,003,642 | 11,538,558 | 7,612,667 |
| Adjustment To PEO Compensation, Footnote | Compensation actually paid to our Named Executive Officers represents the "Total" compensation reported in the Summary Compensation Table for the applicable fiscal year, adjusted set forth in the following table. As described above, awards under our annual bonus program are paid, in part, in the form of restricted stock that is granted in the fiscal year following the applicable performance year, and that vests over a four-year period following the grant date. In accordance with SEC guidance, we disclose the dollar-denominated value of these awards in the "Non-Equity Incentive Compensation" column of the Summary Compensation Table with respect to the applicable performance year (rather than as "Stock Awards" for the year of grant); as such, we believe the awards are not required to be included in the adjustments to calculating compensation actually paid. However, in an effort to comply with the spirit of the SEC pay versus performance rules relating to the adjustments for outstanding equity awards, we have treated the restricted stock awards as equity awards and captured them as part of the adjustments below. Fiscal Year Summary Compensation Table Total ($) Less: Stock Awards Granted for Fiscal Year ($) Add: Unvested Equity Awards Granted for Fiscal Year ($) Increase/(Decrease) in Value of Unvested Equity Awards Granted in Prior Fiscal Years ($) Increase/(Decrease) in Value of Equity Awards Vested During Fiscal Year ($) Compensation Actually Paid ($)(a)(b)(c) Principal Executive Officer 2023 7,000,000 (1,137,500) 1,137,500 53,895 (50,253) 7,003,642 2022 10,650,000 (1,776,250) 1,776,250 759,002 129,556 11,538,558 2021 6,900,000 (1,338,000) 1,338,000 463,549 249,118 7,612,667 Other Named Executive Officers ( Average ) 2023 4,587,500 (722,313) 722,313 53,068 (45,690) 4,594,878 2022 10,162,500 (1,730,750) 1,730,750 675,990 107,679 10,946,169 2021 6,712,500 (1,339,875) 1,339,875 405,259 179,825 7,297,584 (a) Our NEOs did not participate in any Company pension plans during the covered fiscal years; therefore, there are no compensation adjustments for pension values or pension service costs. (b) Our NEOs did not receive any dividends or dividend equivalents from the Company during the covered fiscal years; therefore, there are no such related compensation adjustments. (c) Our NEOs did not have any award forfeitures or accelerations during the covered fiscal years; therefore, there are no such related compensation adjustments. | | |
| Non-PEO NEO Average Total Compensation Amount | $ 4,587,500 | 10,162,500 | 6,712,500 |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 4,594,878 | 10,946,169 | 7,297,584 |
| Adjustment to Non-PEO NEO Compensation Footnote | Compensation actually paid to our Named Executive Officers represents the "Total" compensation reported in the Summary Compensation Table for the applicable fiscal year, adjusted set forth in the following table. As described above, awards under our annual bonus program are paid, in part, in the form of restricted stock that is granted in the fiscal year following the applicable performance year, and that vests over a four-year period following the grant date. In accordance with SEC guidance, we disclose the dollar-denominated value of these awards in the "Non-Equity Incentive Compensation" column of the Summary Compensation Table with respect to the applicable performance year (rather than as "Stock Awards" for the year of grant); as such, we believe the awards are not required to be included in the adjustments to calculating compensation actually paid. However, in an effort to comply with the spirit of the SEC pay versus performance rules relating to the adjustments for outstanding equity awards, we have treated the restricted stock awards as equity awards and captured them as part of the adjustments below. Fiscal Year Summary Compensation Table Total ($) Less: Stock Awards Granted for Fiscal Year ($) Add: Unvested Equity Awards Granted for Fiscal Year ($) Increase/(Decrease) in Value of Unvested Equity Awards Granted in Prior Fiscal Years ($) Increase/(Decrease) in Value of Equity Awards Vested During Fiscal Year ($) Compensation Actually Paid ($)(a)(b)(c) Principal Executive Officer 2023 7,000,000 (1,137,500) 1,137,500 53,895 (50,253) 7,003,642 2022 10,650,000 (1,776,250) 1,776,250 759,002 129,556 11,538,558 2021 6,900,000 (1,338,000) 1,338,000 463,549 249,118 7,612,667 Other Named Executive Officers ( Average ) 2023 4,587,500 (722,313) 722,313 53,068 (45,690) 4,594,878 2022 10,162,500 (1,730,750) 1,730,750 675,990 107,679 10,946,169 2021 6,712,500 (1,339,875) 1,339,875 405,259 179,825 7,297,584 (a) Our NEOs did not participate in any Company pension plans during the covered fiscal years; therefore, there are no compensation adjustments for pension values or pension service costs. (b) Our NEOs did not receive any dividends or dividend equivalents from the Company during the covered fiscal years; therefore, there are no such related compensation adjustments. (c) Our NEOs did not have any award forfeitures or accelerations during the covered fiscal years; therefore, there are no such related compensation adjustments. | | |
| Compensation Actually Paid vs. Total Shareholder Return | Compensation Actually Paid versus Total Shareholder Return The TSR amounts reported in the graph below assume an initial fixed investment of $100, and that all dividends, if any, were reinvested. | | |
| Compensation Actually Paid vs. Net Income | Compensation Actually Paid versus GAAP Net Income | | |
| Compensation Actually Paid vs. Company Selected Measure | Compensation Actually Paid versus GAAP Revenue | | |
| Total Shareholder Return Vs Peer Group | Compensation Actually Paid versus Total Shareholder Return The TSR amounts reported in the graph below assume an initial fixed investment of $100, and that all dividends, if any, were reinvested. | | |
| Tabular List, Table | Pay Versus Performance Tabular List We believe Revenue, net income, and TSR represent the most important financial performance measures used by us to link compensation actually paid to our NEOs for the 2023 fiscal year. | | |
| Total Shareholder Return Amount | $ 172 | 172 | 130 |
| Peer Group Total Shareholder Return Amount | 165 | 192 | 167 |
| Net Income (Loss) | $ 254,000,000 | $ 438,000,000 | $ 313,000,000 |
| Company Selected Measure Amount | 1,809 | 2,270 | 1,525 |
| PEO Name | Scott Beiser | | |
| Additional 402(v) Disclosure | Amounts reported in this column represent (i) the total compensation reported in the SCT for the applicable year in the case of the PEO and (ii) the average of the total compensation reported in the SCT for the applicable year for our other Named Executive Officers excluding the PEO. | | |
| Measure:: 1 | | | |
| Pay vs Performance Disclosure | | | |
| Name | Revenue | | |
| Measure:: 2 | | | |
| Pay vs Performance Disclosure | | | |
| Name | net income | | |
| Measure:: 3 | | | |
| Pay vs Performance Disclosure | | | |
| Name | TSR | | |
| PEO | Equity Awards Granted During the Year, Vested [Member] | | | |
| Pay vs Performance Disclosure | | | |
| Adjustment to Compensation, Amount | $ (1,137,500) | $ (1,776,250) | $ (1,338,000) |
| PEO | Equity Awards Granted During the Year, Unvested [Member] | | | |
| Pay vs Performance Disclosure | | | |
| Adjustment to Compensation, Amount | 1,137,500 | 1,776,250 | 1,338,000 |
| PEO | Equity Awards Granted in Prior Years, Unvested [Member] | | | |
| Pay vs Performance Disclosure | | | |
| Adjustment to Compensation, Amount | 53,895 | 759,002 | 463,549 |
| PEO | Equity Awards Granted in Prior Years, Vested [Member] | | | |
| Pay vs Performance Disclosure | | | |
| Adjustment to Compensation, Amount | (50,253) | 129,556 | 249,118 |
| Non-PEO NEO | Equity Awards Granted During the Year, Vested [Member] | | | |
| Pay vs Performance Disclosure | | | |
| Adjustment to Compensation, Amount | (722,313) | (1,730,750) | (1,339,875) |
| Non-PEO NEO | Equity Awards Granted During the Year, Unvested [Member] | | | |
| Pay vs Performance Disclosure | | | |
| Adjustment to Compensation, Amount | 722,313 | 1,730,750 | 1,339,875 |
| Non-PEO NEO | Equity Awards Granted in Prior Years, Unvested [Member] | | | |
| Pay vs Performance Disclosure | | | |
| Adjustment to Compensation, Amount | 53,068 | 675,990 | 405,259 |
| Non-PEO NEO | Equity Awards Granted in Prior Years, Vested [Member] | | | |
| Pay vs Performance Disclosure | | | |
| Adjustment to Compensation, Amount | $ (45,690) | $ 107,679 | $ 179,825 |
