BORROWINGS - Schedule of Borrowings Outstanding (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Mar. 31, 2022
Debt Instrument [Line Items]
Outstanding Balance	$ 610,000	$ 535,000
Unamortized Debt Issuance Costs and Debt Discount/Premium	(6,671)	(6,412)
Recorded Value	603,329	528,588
Line of Credit | Credit Facility
Debt Instrument [Line Items]
Outstanding Balance	240,000
Unamortized Debt Issuance Costs and Debt Discount/Premium	0
Recorded Value	240,000
SBA Debentures | Unsecured Debt
Debt Instrument [Line Items]
Outstanding Balance	80,000	40,000
Unamortized Debt Issuance Costs and Debt Discount/Premium	(2,447)	(1,648)
Recorded Value	77,553	38,352
Credit Facility | Line of Credit
Debt Instrument [Line Items]
Outstanding Balance		205,000
Unamortized Debt Issuance Costs and Debt Discount/Premium		0
Recorded Value		205,000
January 2026 Notes | Notes
Debt Instrument [Line Items]
Outstanding Balance	140,000	140,000
Unamortized Debt Issuance Costs and Debt Discount/Premium	(1,117)	(1,286)
Recorded Value	138,883	138,714
October 2026 Notes | Notes
Debt Instrument [Line Items]
Outstanding Balance	150,000	150,000
Unamortized Debt Issuance Costs and Debt Discount/Premium	(3,107)	(3,478)
Recorded Value	$ 146,893	$ 146,522