Members' Capital - Schedule of Distributable Earnings (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Investment Company, Net Assets [Roll Forward]
Net distributable earnings (accumulated losses), beginning of period			$ (71,561)
Net investment income (loss)	$ 36,173	$ 12,088	66,659	$ 15,846
Net realized gain (loss)	0	(122)	42	(122)
Net change in unrealized appreciation (depreciation)	12,019	(38,330)	20,219	(44,402)
Distributions declared	(35,783)	$ (12,429)	(67,504)	(16,356)
Net distributable earnings (accumulated losses), end of period	(52,145)		(52,145)		$ (71,561)
Net distributable earnings (accumulated losses)
Investment Company, Net Assets [Roll Forward]
Net distributable earnings (accumulated losses), beginning of period			(71,561)	$ (491)	(491)
Net investment income (loss)			66,659		67,006
Net realized gain (loss)			42		(448)
Net change in unrealized appreciation (depreciation)			20,219		(76,254)
Distributions declared			(67,504)		(62,264)
Tax reclassification of unitholders' equity (Note 10)			0		890
Net distributable earnings (accumulated losses), end of period	$ (52,145)		$ (52,145)		$ (71,561)