BORROWINGS - Contractual Payment Obligations (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Mar. 31, 2025
Debt Instrument [Line Items]
2026	$ 221,875
2027	0
2028	0
2029	77,000
2030	230,000
Thereafter	525,000
Outstanding Balance	1,053,875	$ 969,875
SBA Debentures \| Unsecured Debt
Debt Instrument [Line Items]
2026	0
2027	0
2028	0
2029	0
2030	0
Thereafter	175,000
Outstanding Balance	175,000	175,000
SPV Credit Facility \| Line of Credit \| SPV Credit Facility
Debt Instrument [Line Items]
2026	0
2027	0
2028	0
2029	77,000
2030	0
Thereafter	0
Outstanding Balance	77,000	108,000
October 2026 Notes \| Notes
Debt Instrument [Line Items]
2026	150,000
2027	0
2028	0
2029	0
2030	0
Thereafter	0
Outstanding Balance	150,000	150,000
August 2028 Notes \| Notes
Debt Instrument [Line Items]
2026	71,875
2027	0
2028	0
2029	0
2030	0
Thereafter	0
Outstanding Balance	71,875	71,875
2029 Convertible Notes \| Convertible Debt
Debt Instrument [Line Items]
2026	0
2027	0
2028	0
2029	0
2030	230,000
Thereafter	0
Outstanding Balance	230,000	$ 230,000
September 2030 Notes \| Notes
Debt Instrument [Line Items]
2026	0
2027	0
2028	0
2029	0
2030	0
Thereafter	350,000
Outstanding Balance	$ 350,000

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