Transactions with Affiliate Companies - Schedule of Income Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income	$ 126,062	$ 101,733	$ 350,188	$ 266,721
Other income	518	3,405	1,348	6,065
Non-controlled affiliate company investments
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			7,379	3,877
Dividend income			2,473	0
Other income	$ 21	$ 0	63	0
Non-controlled affiliate company investments | Baystate Sewage Disposal, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			122	0
Dividend income			180	0
Other income			0	0
Non-controlled affiliate company investments | Born To Run, LLC.
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | ClearlyRated Capital (Class A Units)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			75	0
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | Engineered Metal Solutions, Inc.
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			17	0
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | MC Aviation Limited
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | MC Voyager SPV II LLC (Equity Commitment)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | Nastel Technologies, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			292	326
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | NFS Intermediate Holdco, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			2,293	0
Other income			0	0
Non-controlled affiliate company investments | Second Avenue S F R Holdings I I L L C
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	283
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | S F R Holdco, L L C
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			752	615
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | S F R Holdco 2, L L C
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			208	0
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | SheerTrans Solutions, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			741	770
Dividend income			0	0
Other income			42	0
Non-controlled affiliate company investments | Summit Professional Education, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			990	543
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | Triad Financial Services, Inc.
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | Whistler Parent Holdings III, Inc.
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			2,719	0
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | YBR OZ ECE, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			155	0
Dividend income			0	0
Other income			0	0
Non-controlled affiliate company investments | Zodega Landscaping, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			1,308	1,340
Dividend income			0	0
Other income			21	0
Investment, Identifier [Axis]: BTR Opco LLC (Class A units)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: BTR Opco LLC (Delayed Draw)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: BTR Opco LLC 1
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: BTR Opco LLC 2
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: Baystate Sewage Disposal, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			119
Dividend income			0
Other income			0
Investment, Identifier [Axis]: Baystate Sewage Disposal, LLC (Class A-1 preferred units)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0
Dividend income			180
Other income			0
Investment, Identifier [Axis]: Baystate Sewage Disposal, LLC (Delayed Draw)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			2
Dividend income			0
Other income			0
Investment, Identifier [Axis]: Baystate Sewage Disposal, LLC (Revolver)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			1
Dividend income			0
Other income			0
Investment, Identifier [Axis]: ClearlyRated Capital, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			73
Dividend income			0
Other income			0
Investment, Identifier [Axis]: ClearlyRated Capital, LLC (Class A units)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: ClearlyRated Capital, LLC (Delayed Draw)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			2
Dividend income			0
Other income			0
Investment, Identifier [Axis]: Engineered Metal Solutions, Inc.
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			17
Dividend income			0
Other income			0
Investment, Identifier [Axis]: Engineered Metal Solutions, Inc. (Class A units)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0
Dividend income			0
Other income			0
Investment, Identifier [Axis]: Engineered Metal Solutions, Inc. (Revolver)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0
Dividend income			0
Other income			0
Investment, Identifier [Axis]: MC Aviation Limited
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0
Dividend income			0
Other income			0
Investment, Identifier [Axis]: MC Voyager SPV II LLC (Equity commitment)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0
Dividend income			0
Other income			0
Investment, Identifier [Axis]: NFS Intermediate HoldCo, LLC (Series B preferred units)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0
Dividend income			2,293
Other income			0
Investment, Identifier [Axis]: Nastel Technologies, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			291	326
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: Nastel Technologies, LLC (Class A units)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: Nastel Technologies, LLC (Revolver)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			1	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: SFR Holdco 2, LLC (Delayed Draw)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			208
Dividend income			0
Other income			0
Investment, Identifier [Axis]: SFR Holdco 2, LLC (LLC interest)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0
Dividend income			0
Other income
Investment, Identifier [Axis]: SFR Holdco, LLC (LLC interest) 1
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: SFR Holdco, LLC (LLC interest) 2
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: SFR Holdco, LLC 1
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			444	351
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: SFR Holdco, LLC 2
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			308	264
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: Second Avenue SFR Holdings II LLC (Revolver)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income				283
Dividend income				0
Other income				0
Investment, Identifier [Axis]: SheerTrans Solutions, LLC (Preferred interests)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: SheerTrans Solutions, LLC (Revolver)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			75	101
Dividend income			0	0
Other income			8	0
Investment, Identifier [Axis]: SheerTrans Solutions, LLC 1
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			520	540
Dividend income			0	0
Other income			26	0
Investment, Identifier [Axis]: SheerTrans Solutions, LLC 2
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			146	129
Dividend income			0	0
Other income			8	0
Investment, Identifier [Axis]: Summit Professional Education, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			8
Dividend income			0
Other income			0
Investment, Identifier [Axis]: Summit Professional Education, LLC (Class A units)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: Summit Professional Education, LLC (Revolver)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			34	3
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: Summit Professional Education, LLC 1
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			93
Dividend income			0
Other income			0
Investment, Identifier [Axis]: Summit Professional Education, LLC 2
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			855	540
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: Triad Financial Services, Inc. (Equity commitment)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: Whistler Parent Holdings III, Inc.
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			2,340
Dividend income			0
Other income			0
Investment, Identifier [Axis]: Whistler Parent Holdings III, Inc. (Delayed Draw)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			219
Dividend income			0
Other income			0
Investment, Identifier [Axis]: Whistler Parent Holdings III, Inc. (Revolver)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			160
Dividend income			0
Other income			0
Investment, Identifier [Axis]: Whistler Parent Holdings III, Inc. (Series A preferred stock)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0
Dividend income			0
Other income			0
Investment, Identifier [Axis]: Whistler Parent Holdings III, Inc. (Series B preferred stock)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0
Dividend income			0
Other income			0
Investment, Identifier [Axis]: YBR OZ ECE, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			146
Dividend income			0
Other income			0
Investment, Identifier [Axis]: YBR OZ ECE, LLC (Class A units)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0
Dividend income			0
Other income			0
Investment, Identifier [Axis]: YBR OZ ECE, LLC (Delayed Draw)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			9
Dividend income			0
Other income			0
Investment, Identifier [Axis]: YBR OZ ECE, LLC (Revolver)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0
Dividend income			0
Other income			0
Investment, Identifier [Axis]: Zodega Landscaping, LLC
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			1,213	1,312
Dividend income			0	0
Other income			18	0
Investment, Identifier [Axis]: Zodega Landscaping, LLC (Preferred interests)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			0	0
Dividend income			0	0
Other income			0	0
Investment, Identifier [Axis]: Zodega Landscaping, LLC (Revolver)
Investments in and Advances to Affiliates, Activity [Line Items]
Interest Income			95	28
Dividend income			0	0
Other income			$ 3	$ 0