Investments, at Fair Value - Continuous Loss Position (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Total available-for-sale debt securities with unrealized losses	$ 1,964	$ 75,900
Unrealized Losses, Total available-for-sale debt securities with unrealized losses	1,060	8,880
Corporate debt securities (L Bonds)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Twelve months or longer	0	73,822
Unrealized Losses, Twelve months or longer	0	7,924
Other debt securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Less than twelve months	0	2,078
Fair Value, Twelve months or longer	1,964	0
Unrealized Losses, Less than twelve months	0	956
Unrealized Losses, Twelve months or longer	$ 1,060	$ 0