Income Taxes - Summary of Reconciliation of Net Increase in Net Assets Resulting from Operations to Taxable Income (Details) - USD ($) $ in Thousands	3 Months Ended												9 Months Ended		12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Net increase (decrease) in net assets resulting from operations	$ 1,288	$ 15,993	$ 5,659	$ 4,239	$ 20,540	$ 25,441	$ 32,144	$ 42,411	$ 33,166	$ 33,289	$ 2,995	$ (147,247)	$ 22,940	$ 78,125	$ 82,364	$ 111,861
Net realized (gains) losses													69,239		67,367	21,506
Net change in unrealized (gains) losses													(18,036)		(53,771)	(23,341)
Income (loss) recognized for tax but not book													(1,419)		4,596	7,673
Realized gain/loss differences													(7,723)		(13,316)	(7,933)
Taxable income before deductions for distributions													$ 65,001		$ 87,240	$ 109,766