Portfolio Company Investments - Schedule of Consolidated Schedule of Investments in and Advances to Affiliates (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2023	Dec. 31, 2022
Control Investments
Investments in and Advances to Affiliates [Line Items]
Principal Amount - Debt Investments	$ 14,576	$ 14,576
Fair Value, beginning balance		2,151
Gross Additions		20,174
Gross Reductions		(22,325)
Net Realized Gain (Losses)		(158)
Net Change in Unrealized Appreciation (Depreciation)		(13,233)
Affiliate Investments
Investments in and Advances to Affiliates [Line Items]
Principal Amount - Debt Investments	34,602	34,602
Fair Value, beginning balance	101,590	137,284
Gross Additions	1,517	70,477
Gross Reductions	(4,070)	(106,171)
Fair Value, ending balance	99,037	101,590
Net Realized Gain (Losses)		39,833
Net Change in Unrealized Appreciation (Depreciation)	(2,489)	(35,979)
Interest Income	1,050	3,464
Payment-in-kind Interest Income		30
Dividend Income	348	725
Fee Income	5	457
EBL, LLC (EbLens) \| Control Investments
Investments in and Advances to Affiliates [Line Items]
Principal Amount - Debt Investments	9,350	9,350
Gross Additions		19,628
Gross Reductions		(19,628)
Net Change in Unrealized Appreciation (Depreciation)		(11,083)
Hilco Plastics Holdings, LLC (dba Hilco Technologies) \| Control Investments
Investments in and Advances to Affiliates [Line Items]
Gross Additions		353
Gross Reductions		(353)
Net Realized Gain (Losses)		(352)
Mesa Line Services, LLC \| Control Investments
Investments in and Advances to Affiliates [Line Items]
Fair Value, beginning balance		2,151
Gross Additions		193
Gross Reductions		(2,344)
Net Realized Gain (Losses)		194
Net Change in Unrealized Appreciation (Depreciation)		(2,150)
US GreenFiber, LLC \| Control Investments
Investments in and Advances to Affiliates [Line Items]
Principal Amount - Debt Investments	5,226	5,226
Applegate Greenfiber Intermediate Inc. (fka US GreenFiber, LLC) \| Affiliate Investments
Investments in and Advances to Affiliates [Line Items]
Principal Amount - Debt Investments	9,602	9,602
Fair Value, beginning balance	23,168	22,405
Gross Additions	377	13,566
Gross Reductions		(12,803)
Fair Value, ending balance	23,545	23,168
Net Change in Unrealized Appreciation (Depreciation)	378	763
Interest Income	240	973
FAR Research Inc. \| Affiliate Investments
Investments in and Advances to Affiliates [Line Items]
Fair Value, beginning balance		28
Gross Reductions		(28)
Net Change in Unrealized Appreciation (Depreciation)		(28)
Medsurant Holdings, LLC \| Affiliate Investments
Investments in and Advances to Affiliates [Line Items]
Fair Value, beginning balance	2,540	3,662
Gross Additions	407
Gross Reductions	(73)	(1,122)
Fair Value, ending balance	2,874	2,540
Net Change in Unrealized Appreciation (Depreciation)	407	(1,122)
Mirage Trailers LLC \| Affiliate Investments
Investments in and Advances to Affiliates [Line Items]
Fair Value, beginning balance		10,675
Gross Additions		355
Gross Reductions		(11,030)
Net Realized Gain (Losses)		324
Net Change in Unrealized Appreciation (Depreciation)		(1,694)
Interest Income		248
Payment-in-kind Interest Income		29
Fee Income		132
Pfanstiehl, Inc \| Affiliate Investments
Investments in and Advances to Affiliates [Line Items]
Principal Amount - Debt Investments	10,000	10,000
Fair Value, beginning balance	51,992	57,639
Gross Additions	2	34,335
Gross Reductions	(1,019)	(39,982)
Fair Value, ending balance	50,975	51,992
Net Realized Gain (Losses)		24,330
Net Change in Unrealized Appreciation (Depreciation)	(1,021)	(15,432)
Interest Income	249	421
Dividend Income	348
Fee Income		150
Pinnergy, Ltd. \| Affiliate Investments
Investments in and Advances to Affiliates [Line Items]
Fair Value, beginning balance		21,178
Gross Additions		15,300
Gross Reductions		(36,478)
Net Realized Gain (Losses)		15,300
Net Change in Unrealized Appreciation (Depreciation)		(18,177)
Dividend Income		656
Spectra A&D Acquisition, Inc. (fka FDS Avionics Corp.) \| Affiliate Investments
Investments in and Advances to Affiliates [Line Items]
Principal Amount - Debt Investments	15,000	15,000
Fair Value, beginning balance	19,118	18,359
Gross Additions	6	5,487
Gross Reductions	(2,978)	(4,728)
Fair Value, ending balance	16,146	19,118
Net Realized Gain (Losses)		(121)
Net Change in Unrealized Appreciation (Depreciation)	(2,978)	(1,723)
Interest Income	561	1,822
Fee Income	5	175
Steward Holding LLC (dba Steward Advanced Materials) \| Affiliate Investments
Investments in and Advances to Affiliates [Line Items]
Fair Value, beginning balance	4,772	3,338
Gross Additions	725	1,434
Fair Value, ending balance	5,497	4,772
Net Change in Unrealized Appreciation (Depreciation)	$ 725	1,434
Payment-in-kind Interest Income		1
Dividend Income		$ 69

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Value of the investment at close of period. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.

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