Investments and Fair Value Measurements - Summary of Changes in Fair Value of Investments for Which Level 3 Inputs Were Used to Determine Fair Value (Details) - Level 3 - USD ($)	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance as of January 1	$ 410,096,869	$ 516,143,925
Purchases and drawdowns of investments	62,822,654	67,033,101
Proceeds from principal pre-payments and sales of investments	(167,138,451)	(133,869,360)
Payment-in-kind	2,081,717	1,535,311
Net accretion of discount on investments	1,755,703	1,282,377
Net change in unrealized appreciation (depreciation) on investments	(21,342,254)	(5,390,048)
Net realized gain (loss) on investments	519,829	(1,431,596)
Transfers out of Level 3		(22,664,600)
Balance as of September 30	288,796,067	422,639,110
Net change in unrealized appreciation (depreciation) on Level 3 investments still held	(21,822,743)	(7,278,737)
Senior Secured Loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance as of January 1	404,135,270	509,110,614
Purchases and drawdowns of investments	58,835,053	66,869,354
Proceeds from principal pre-payments and sales of investments	(166,241,429)	(133,869,360)
Payment-in-kind	2,081,717	1,535,311
Net accretion of discount on investments	1,755,703	1,282,377
Net change in unrealized appreciation (depreciation) on investments	(19,888,905)	(4,152,981)
Net realized gain (loss) on investments	602,469	(1,431,596)
Transfers out of Level 3		(22,664,600)
Balance as of September 30	281,279,878	416,679,119
Net change in unrealized appreciation (depreciation) on Level 3 investments still held	$ (20,449,937)	$ (6,041,670)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Gain (Loss), Investment and Derivative, Operating, after Tax	Gain (Loss), Investment and Derivative, Operating, after Tax
Equity
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance as of January 1	$ 5,961,599	$ 7,033,311
Purchases and drawdowns of investments	3,987,601	163,747
Proceeds from principal pre-payments and sales of investments	(897,022)
Net change in unrealized appreciation (depreciation) on investments	(1,453,349)	(1,237,067)
Net realized gain (loss) on investments	(82,640)
Balance as of September 30	7,516,189	5,959,991
Net change in unrealized appreciation (depreciation) on Level 3 investments still held	$ (1,372,806)	$ (1,237,067)

Onex Direct Lending BDC Fund 10-Q