Investment Portfolio - Sustainable Infrastructure Investments, LLC Portfolio (Details) $ in Thousands, $ in Thousands		Jun. 30, 2023 USD ($)		Jun. 30, 2023 CAD ($)		Dec. 31, 2022 USD ($)		Dec. 31, 2022 CAD ($)		Dec. 31, 2021 USD ($)		Jan. 02, 2020 USD ($)
Schedule of Investments [Line Items]
Amortized Cost		$ 1,406,338	[1]			$ 1,922,940	[2]
Investments, at fair value		$ 1,495,602	[1],[3]			$ 2,047,115	[2],[4]
Percent of net assets		89.00%	[1]	89.00%	[1]	116.70%	[2]	116.70%	[2]
London Interbank Offered Rate (LIBOR)
Schedule of Investments [Line Items]
Investment, variable rate		5.55%		5.55%		4.77%		4.77%
Secured Overnight Financing Rate
Schedule of Investments [Line Items]
Investment, variable rate		5.27%		5.27%		4.59%		4.59%
Net Senior Secured Loans—First Lien
Schedule of Investments [Line Items]
Amortized Cost		$ 531,752	[1]			$ 702,842	[2]
Investments, at fair value		$ 522,029	[1],[3]			$ 706,646	[2],[4]
Percent of net assets		31.10%	[1]	31.10%	[1]	40.30%	[2]	40.30%	[2]
Investment, Identifier [Axis]: AIRRO (Mauritius) Holdings II, Energy—Power 1
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6],[7],[8]	4.00%		4.00%
Principal amount	[1],[6],[7],[8],[9]	$ 23,071
Amortized Cost	[1],[6],[7],[8]	20,419
Investments, at fair value	[1],[3],[6],[7],[8]	$ 23,243
Investment, Identifier [Axis]: AIRRO (Mauritius) Holdings II, Energy—Power 2
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6],[7],[8],[10]	4.00%		4.00%
Principal amount	[1],[6],[7],[8],[9],[10]	$ 5,359
Amortized Cost	[1],[6],[7],[8],[10]	5,359
Investments, at fair value	[1],[3],[6],[7],[8],[10]	5,399
Investment, Identifier [Axis]: AIRRO (Mauritius) Holdings II, Power 1
Schedule of Investments [Line Items]
Variable rate	[2],[11],[12],[13]					4.00%		4.00%
Principal amount	[2],[11],[12],[13],[14]					$ 22,734
Amortized Cost	[2],[11],[12],[13]					20,082
Investments, at fair value	[2],[4],[11],[12],[13]					$ 23,519
Investment, Identifier [Axis]: AIRRO (Mauritius) Holdings II, Power 2
Schedule of Investments [Line Items]
Variable rate	[2],[11],[12],[13],[15]					4.00%		4.00%
Principal amount	[2],[11],[12],[13],[14],[15]					$ 5,359
Amortized Cost	[2],[11],[12],[13],[15]					5,359
Investments, at fair value	[2],[4],[11],[12],[13],[15]					5,545
Investment, Identifier [Axis]: AIRRO (Mauritius) Holdings II, Warrants, Strike: $1.00, Energy—Power
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[7],[8],[16]	2,652
Investments, at fair value	[1],[3],[6],[7],[8],[16]	2,223
Investment, Identifier [Axis]: AIRRO (Mauritius) Holdings II, Warrants, Strike: $1.00, Power
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[12],[13],[17],[18]					2,652
Investments, at fair value	[2],[4],[11],[12],[13],[17],[18]					1,630
Investment, Identifier [Axis]: Abaco Energy Technologies LLC, Common Equity, Energy—Service & Equipment
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16]	6,944
Investments, at fair value	[1],[3],[6],[16]	1,243
Investment, Identifier [Axis]: Abaco Energy Technologies LLC, Common Equity, Service & Equipment
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18]					6,944
Investments, at fair value	[2],[4],[11],[17],[18]					1,219
Investment, Identifier [Axis]: Abaco Energy Technologies LLC, Preferred Equity, Energy—Service & Equipment
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16]	1,447
Investments, at fair value	[1],[3],[6],[16]	$ 8,827
Investment, Identifier [Axis]: Abaco Energy Technologies LLC, Preferred Equity, Service & Equipment
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18]					1,447
Investments, at fair value	[2],[4],[11],[17],[18]					$ 8,321
Investment, Identifier [Axis]: Acrisure, LLC, Insurance
Schedule of Investments [Line Items]
Variable rate	[1],[5]	5.75%		5.75%
Principal amount	[1],[9]	$ 9,975
Amortized Cost	[1]	10,044
Investments, at fair value	[1],[3]	$ 10,062
Investment, Identifier [Axis]: Aethon III BR LLC, Energy—Upstream
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6]	7.50%		7.50%
Principal amount	[1],[6],[9]	$ 20,000
Amortized Cost	[1],[6]	19,877
Investments, at fair value	[1],[3],[6]	20,081
Investment, Identifier [Axis]: Aethon III BR LLC, Upstream
Schedule of Investments [Line Items]
Variable rate	[2],[11],[18]					7.50%		7.50%
Principal amount	[2],[11],[14],[18]					$ 20,000
Amortized Cost	[2],[11],[18]					19,848
Investments, at fair value	[2],[4],[11],[18]					20,138
Investment, Identifier [Axis]: Aethon United BR LP, Energy—Upstream
Schedule of Investments [Line Items]
Principal amount	[1],[9]	40,500
Amortized Cost	[1]	40,500
Investments, at fair value	[1],[3]	39,828
Investment, Identifier [Axis]: Aethon United BR LP, Upstream
Schedule of Investments [Line Items]
Principal amount	[2],[14],[18]					40,500
Amortized Cost	[2],[18]					40,500
Investments, at fair value	[2],[4],[18]					40,221
Investment, Identifier [Axis]: AirSwift Holdings, Ltd., Common Equity, Commercial & Professional Services
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[8],[16]	6,029
Investments, at fair value	[1],[3],[6],[8],[16]	3,038
Investment, Identifier [Axis]: Allied Downhole Technologies, LLC
Schedule of Investments [Line Items]
Investments, at fair value		7,553	[19]			8,436	[19],[20]			$ 7,782	[20]
Investment, Identifier [Axis]: Allied Downhole Technologies, LLC, Energy—Service & Equipment 1
Schedule of Investments [Line Items]
Principal amount	[1],[6],[9],[21]	7,553
Amortized Cost	[1],[6],[21]	7,553
Investments, at fair value	[1],[3],[6],[21]	7,553
Investment, Identifier [Axis]: Allied Downhole Technologies, LLC, Energy—Service & Equipment 2
Schedule of Investments [Line Items]
Principal amount	[1],[6],[9],[10],[21]	2,500
Amortized Cost	[1],[6],[10],[21]	2,500
Investments, at fair value	[1],[3],[6],[10],[21]	$ 2,500
Investment, Identifier [Axis]: Allied Downhole Technologies, LLC, Service & Equipment 1
Schedule of Investments [Line Items]
Principal amount	[2],[11],[14],[18],[22]					8,436
Amortized Cost	[2],[11],[18],[22]					8,436
Investments, at fair value	[2],[4],[11],[18],[22]					8,436
Investment, Identifier [Axis]: Allied Downhole Technologies, LLC, Service & Equipment 2
Schedule of Investments [Line Items]
Principal amount	[2],[11],[14],[15],[22]					2,500
Amortized Cost	[2],[11],[15],[22]					2,500
Investments, at fair value	[2],[4],[11],[15],[22]					2,500
Investment, Identifier [Axis]: Allied Universal Holdco, LLC, Consumer Services
Schedule of Investments [Line Items]
Variable rate	[1],[5]	3.75%		3.75%
Principal amount	[1],[9]	$ 7,980
Amortized Cost	[1]	7,671
Investments, at fair value	[1],[3]	7,771
Investment, Identifier [Axis]: Allied Wireline Services, LLC
Schedule of Investments [Line Items]
Investments, at fair value		70,277				63,888				46,339
Investment, Identifier [Axis]: Allied Wireline Services, LLC, Common Equity
Schedule of Investments [Line Items]
Investments, at fair value		8,068				10,463				0
Investment, Identifier [Axis]: Allied Wireline Services, LLC, Common Equity, Energy—Service & Equipment
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16],[21],[23]	1,527
Investments, at fair value	[1],[3],[6],[16],[21],[23]	8,068
Investment, Identifier [Axis]: Allied Wireline Services, LLC, Common Equity, Service & Equipment
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18],[22],[24]					1,527
Investments, at fair value	[2],[4],[11],[17],[18],[22],[24]					10,463
Investment, Identifier [Axis]: Allied Wireline Services, LLC, Energy—Service & Equipment
Schedule of Investments [Line Items]
Principal amount	[1],[6],[9],[21]	70,277
Amortized Cost	[1],[6],[21]	70,277
Investments, at fair value	[1],[3],[6],[21]	70,277
Investment, Identifier [Axis]: Allied Wireline Services, LLC, Service & Equipment
Schedule of Investments [Line Items]
Principal amount	[2],[11],[14],[18],[22]					63,888
Amortized Cost	[2],[11],[18],[22]					63,888
Investments, at fair value	[2],[4],[11],[18],[22]					63,888
Investment, Identifier [Axis]: Allied Wireline Services, LLC, Warrants
Schedule of Investments [Line Items]
Investments, at fair value		0				0				0
Investment, Identifier [Axis]: Allied Wireline Services, LLC, Warrants, Energy—Service & Equipment
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16],[21],[23]	0
Investments, at fair value	[1],[3],[6],[16],[21],[23]	0
Investment, Identifier [Axis]: Allied Wireline Services, LLC, Warrants, Service & Equipment
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18],[22],[24]					0
Investments, at fair value	[2],[4],[11],[17],[18],[22],[24]					0
Investment, Identifier [Axis]: Archrock Partners, L.P., Midstream
Schedule of Investments [Line Items]
Principal amount	[2],[13],[14],[18]					3,098
Amortized Cost	[2],[13],[18]					3,168
Investments, at fair value	[2],[4],[13],[18]					2,840
Investment, Identifier [Axis]: Arena Energy, LP, Contingent Value Rights, Energy—Upstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6]	351
Investments, at fair value	[1],[3],[6]	488
Investment, Identifier [Axis]: Arena Energy, LP, Contingent Value Rights, Upstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18]					351
Investments, at fair value	[2],[4],[11],[17],[18]					858
Investment, Identifier [Axis]: Ascent Resources Utica Holdings, LLC, Common Equity, Energy—Upstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16],[23]	44,700
Investments, at fair value	[1],[3],[6],[16],[23]	$ 31,895
Investment, Identifier [Axis]: Ascent Resources Utica Holdings, LLC, Common Equity, Upstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18],[24]					44,700
Investments, at fair value	[2],[4],[11],[17],[18],[24]					$ 52,340
Investment, Identifier [Axis]: Aveanna Healthcare LLC, Health Care Equipment & Services
Schedule of Investments [Line Items]
Variable rate	[1],[5]	3.75%		3.75%
Principal amount	[1],[9]	$ 9,975
Amortized Cost	[1]	8,583
Investments, at fair value	[1],[3]	$ 8,562
Investment, Identifier [Axis]: Brazos Delaware II LLC, Midstream
Schedule of Investments [Line Items]
Variable rate	[2]					4.00%		4.00%
Principal amount	[2],[14]					$ 39,259
Amortized Cost	[2]					38,085
Investments, at fair value	[2],[4]					$ 39,137
Investment, Identifier [Axis]: CPV Maryland, LLC, Power
Schedule of Investments [Line Items]
Variable rate	[2]					4.00%		4.00%
Principal amount	[2],[14]					$ 14,286
Amortized Cost	[2]					14,146
Investments, at fair value	[2],[4]					$ 14,155
Investment, Identifier [Axis]: CPV Shore Holdings LLC, Energy—Power
Schedule of Investments [Line Items]
Variable rate	[1],[5]	3.75%		3.75%
Principal amount	[1],[9]	$ 23,601
Amortized Cost	[1]	22,880
Investments, at fair value	[1],[3]	$ 21,765
Investment, Identifier [Axis]: CPV Shore Holdings LLC, Power
Schedule of Investments [Line Items]
Variable rate	[2]					3.75%		3.75%
Principal amount	[2],[14]					$ 23,601
Amortized Cost	[2]					22,760
Investments, at fair value	[2],[4]					21,935
Investment, Identifier [Axis]: Cimarron Energy Holdco Inc., Common Equity, Service & Equipment
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18]					3,950
Investments, at fair value	[2],[4],[11],[17],[18]					0
Investment, Identifier [Axis]: Cimarron Energy Holdco Inc., Participation Option, Service & Equipment
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18]					1,289
Investments, at fair value	[2],[4],[11],[17],[18]					$ 0
Investment, Identifier [Axis]: Cimarron Energy Inc., Service & Equipment
Schedule of Investments [Line Items]
Variable rate	[2],[11],[17],[18],[25]					9.00%		9.00%
Principal amount	[2],[11],[14],[17],[18],[25]					$ 7,500
Amortized Cost	[2],[11],[17],[18],[25]					6,563
Investments, at fair value	[2],[4],[11],[17],[18],[25]					$ 3,713
Investment, Identifier [Axis]: Citizen Energy Operating, LLC, Energy—Upstream
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6]	7.65%		7.65%
Principal amount	[1],[6],[9]	$ 37,000
Amortized Cost	[1],[6]	36,491
Investments, at fair value	[1],[3],[6]	36,360
Investment, Identifier [Axis]: Citizen Energy Operating, LLC, Upstream
Schedule of Investments [Line Items]
Variable rate	[2],[11],[18]					7.65%		7.65%
Principal amount	[2],[11],[14],[18]					$ 39,000
Amortized Cost	[2],[11],[18]					38,440
Investments, at fair value	[2],[4],[11],[18]					$ 38,240
Investment, Identifier [Axis]: Compass Power Generation LLC, Power
Schedule of Investments [Line Items]
Variable rate	[2]					4.25%		4.25%
Principal amount	[2],[14]					$ 31,575
Amortized Cost	[2]					30,712
Investments, at fair value	[2],[4]					31,384
Investment, Identifier [Axis]: Cox Oil Offshore, LLC, Volumetric Production Payments, Energy—Upstream
Schedule of Investments [Line Items]
Principal amount	[1],[6],[9],[26],[27]	100,000
Amortized Cost	[1],[6],[26],[27]	6,120
Investments, at fair value	[1],[3],[6],[26],[27]	$ 8,507
Investment, Identifier [Axis]: Cox Oil Offshore, LLC, Volumetric Production Payments, Upstream
Schedule of Investments [Line Items]
Principal amount	[2],[11],[14],[28],[29]					100,000
Amortized Cost	[2],[11],[28],[29]					11,081
Investments, at fair value	[2],[4],[11],[28],[29]					$ 20,683
Investment, Identifier [Axis]: EIF Van Hook Holdings, LLC, Midstream
Schedule of Investments [Line Items]
Variable rate	[2]					5.25%		5.25%
Principal amount	[2],[14]					$ 26,882
Amortized Cost	[2]					26,609
Investments, at fair value	[2],[4]					$ 26,075
Investment, Identifier [Axis]: ERA II Minerals, LLC, Energy—Upstream
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6]	6.25%		6.25%
Principal amount	[1],[6],[9]	$ 35,000
Amortized Cost	[1],[6]	34,658
Investments, at fair value	[1],[3],[6]	$ 34,636
Investment, Identifier [Axis]: ERA II Minerals, LLC, Upstream
Schedule of Investments [Line Items]
Variable rate	[2],[11],[18]					6.25%		6.25%
Principal amount	[2],[11],[14],[18]					$ 37,000
Amortized Cost	[2],[11],[18]					36,601
Investments, at fair value	[2],[4],[11],[18]					36,656
Investment, Identifier [Axis]: Earthstone Energy Holdings, LLC, Upstream
Schedule of Investments [Line Items]
Principal amount	[2],[13],[14]					11,400
Amortized Cost	[2],[13]					11,400
Investments, at fair value	[2],[4],[13]					10,920
Investment, Identifier [Axis]: Endeavor Energy Resources, L.P., Upstream
Schedule of Investments [Line Items]
Principal amount	[2],[14],[18]					24,299
Amortized Cost	[2],[18]					25,388
Investments, at fair value	[2],[4],[18]					$ 23,306
Investment, Identifier [Axis]: FR BR Holdings LLC, Energy—Midstream
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6]	6.50%		6.50%
Principal amount	[1],[6],[9]	$ 81,041
Amortized Cost	[1],[6]	80,414
Investments, at fair value	[1],[3],[6]	$ 81,008
Investment, Identifier [Axis]: FR BR Holdings LLC, Midstream
Schedule of Investments [Line Items]
Variable rate	[2],[11],[18]					6.50%		6.50%
Principal amount	[2],[11],[14],[18]					$ 81,582
Amortized Cost	[2],[11],[18]					80,371
Investments, at fair value	[2],[4],[11],[18]					$ 81,361
Investment, Identifier [Axis]: FR XIII PAA Holdings HoldCo, LLC, Energy—Midstream
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6]	7.50%		7.50%
Principal amount	[1],[6],[9]	$ 17,197
Amortized Cost	[1],[6]	16,978
Investments, at fair value	[1],[3],[6]	$ 17,233
Investment, Identifier [Axis]: FR XIII PAA Holdings HoldCo, LLC, Midstream
Schedule of Investments [Line Items]
Variable rate	[2],[11]					7.50%		7.50%
Principal amount	[2],[11],[14]					$ 17,347
Amortized Cost	[2],[11]					17,103
Investments, at fair value	[2],[4],[11]					$ 17,406
Investment, Identifier [Axis]: First Brands Group, LLC, Automobiles & Components
Schedule of Investments [Line Items]
Variable rate	[1],[5]	5.00%		5.00%
Principal amount	[1],[9]	$ 6,982
Amortized Cost	[1]	6,817
Investments, at fair value	[1],[3]	$ 6,853
Investment, Identifier [Axis]: GIP II Blue Holding LP, Energy—Midstream
Schedule of Investments [Line Items]
Variable rate	[1],[5]	4.50%		4.50%
Principal amount	[1],[9]	$ 4,763
Amortized Cost	[1]	4,706
Investments, at fair value	[1],[3]	4,785
Investment, Identifier [Axis]: GIP II Blue Holding LP, Midstream
Schedule of Investments [Line Items]
Variable rate	[2]					4.50%		4.50%
Principal amount	[2],[14]					$ 5,918
Amortized Cost	[2]					5,842
Investments, at fair value	[2],[4]					5,877
Investment, Identifier [Axis]: GWP Midstream Holdco, LLC, Common Equity
Schedule of Investments [Line Items]
Investments, at fair value		1,385				5,044				0
Investment, Identifier [Axis]: GWP Midstream Holdco, LLC, Common Equity, Energy—Midstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16],[23],[30]	6,681
Investments, at fair value	[1],[3],[6],[16],[23],[30]	1,385
Investment, Identifier [Axis]: GWP Midstream Holdco, LLC, Common Equity, Midstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18],[24],[31]					6,681
Investments, at fair value	[2],[4],[11],[17],[18],[24],[31]					$ 5,044
Investment, Identifier [Axis]: GasLog Ltd., Energy—Midstream
Schedule of Investments [Line Items]
Principal amount	[1],[6],[8],[9]	14,648
Amortized Cost	[1],[6],[8]	14,562
Investments, at fair value	[1],[3],[6],[8]	14,012
Investment, Identifier [Axis]: GasLog Ltd., Midstream
Schedule of Investments [Line Items]
Variable rate	[2],[11],[13]					7.75%		7.75%
Principal amount	[2],[11],[13],[14]					$ 14,648
Amortized Cost	[2],[11],[13]					14,556
Investments, at fair value	[2],[4],[11],[13]					$ 14,010
Investment, Identifier [Axis]: Generation Bridge LLC, Power 1
Schedule of Investments [Line Items]
Variable rate	[2]					5.00%		5.00%
Principal amount	[2],[14]					$ 7,432
Amortized Cost	[2]					7,305
Investments, at fair value	[2],[4]					$ 7,385
Investment, Identifier [Axis]: Generation Bridge LLC, Power 2
Schedule of Investments [Line Items]
Variable rate	[2]					5.00%		5.00%
Principal amount	[2],[14]					$ 163
Amortized Cost	[2]					160
Investments, at fair value	[2],[4]					162
Investment, Identifier [Axis]: Global Jet Capital Holdings, LP, Preferred Equity, Commercial & Professional Services 1
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16]	2,786
Investments, at fair value	[1],[3],[6],[16]	0
Investment, Identifier [Axis]: Global Jet Capital Holdings, LP, Preferred Equity, Commercial & Professional Services 2
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16],[32]	12,493
Investments, at fair value	[1],[3],[6],[16],[32]	$ 9,978
Investment, Identifier [Axis]: Global Jet Capital Holdings, LP, Preferred Equity, Industrials 1
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18]					2,786
Investments, at fair value	[2],[4],[11],[17],[18]					0
Investment, Identifier [Axis]: Global Jet Capital Holdings, LP, Preferred Equity, Industrials 2
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18],[25]					12,493
Investments, at fair value	[2],[4],[11],[17],[18],[25]					$ 9,377
Investment, Identifier [Axis]: Goodnight Water Solutions, LLC, Energy—Midstream
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6]	7.00%		7.00%
Principal amount	[1],[6],[9]	$ 14,741
Amortized Cost	[1],[6]	14,544
Investments, at fair value	[1],[3],[6]	14,586
Investment, Identifier [Axis]: Goodnight Water Solutions, LLC, Midstream
Schedule of Investments [Line Items]
Variable rate	[2],[11]					7.25%		7.25%
Principal amount	[2],[11],[14]					$ 14,963
Amortized Cost	[2],[11]					14,752
Investments, at fair value	[2],[4],[11]					14,819
Investment, Identifier [Axis]: Great Western Petroleum, LLC
Schedule of Investments [Line Items]
Investments, at fair value						0				58,055
Investment, Identifier [Axis]: Great Western Petroleum, LLC, Common Equity
Schedule of Investments [Line Items]
Investments, at fair value						0				40,731
Investment, Identifier [Axis]: Guitar Center, Inc., Consumer Discretionary Distribution & Retail
Schedule of Investments [Line Items]
Principal amount	[1],[9]	10,000
Amortized Cost	[1]	9,131
Investments, at fair value	[1],[3]	9,109
Investment, Identifier [Axis]: Hamilton Intermediate Holdings, LLC, Power
Schedule of Investments [Line Items]
Principal amount	[2],[11],[14]					30,391
Amortized Cost	[2],[11]					31,075
Investments, at fair value	[2],[4],[11]					$ 31,007
Investment, Identifier [Axis]: Hammerhead Resources Inc., Energy—Upstream
Schedule of Investments [Line Items]
Principal amount	[1],[6],[8],[9]	37,225
Amortized Cost	[1],[6],[8]	37,114
Investments, at fair value	[1],[3],[6],[8]	37,225
Investment, Identifier [Axis]: Hammerhead Resources Inc., Upstream
Schedule of Investments [Line Items]
Variable rate	[2],[11],[13],[18]					12.00%		12.00%
Principal amount	[2],[11],[13],[14],[18]					$ 35,118
Amortized Cost	[2],[11],[13],[18]					34,961
Investments, at fair value	[2],[4],[11],[13],[18]					35,118
Investment, Identifier [Axis]: Harvest Oil & Gas Corp., Common Equity
Schedule of Investments [Line Items]
Investments, at fair value		810				810				2,836
Investment, Identifier [Axis]: Harvest Oil & Gas Corp., Common Equity, Energy—Upstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16],[30]	14,418
Investments, at fair value	[1],[3],[6],[16],[30]	810
Investment, Identifier [Axis]: Harvest Oil & Gas Corp., Common Equity, Upstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[17],[18],[31]					15,059
Investments, at fair value	[2],[4],[17],[18],[31]					810
Investment, Identifier [Axis]: Limetree Bay Energy, LLC
Schedule of Investments [Line Items]
Investments, at fair value						0				3,166
Investment, Identifier [Axis]: Limetree Bay Energy, LLC, Class A Units
Schedule of Investments [Line Items]
Investments, at fair value		0				1,885				6,046
Investment, Identifier [Axis]: Limetree Bay Energy, LLC, Class A Units, Midstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18],[31]					21,458
Investments, at fair value	[2],[4],[11],[17],[18],[31]					1,885
Investment, Identifier [Axis]: MB Precision Investment Holdings LLC, Class A-2 Units, Industrials
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18],[24]					490
Investments, at fair value	[2],[4],[11],[17],[18],[24]					0
Investment, Identifier [Axis]: MECO IV Holdco, LLC
Schedule of Investments [Line Items]
Investments, at fair value						0				22,745
Investment, Identifier [Axis]: MECO IV Holdco, LLC, Class A-1 Units
Schedule of Investments [Line Items]
Investments, at fair value						0				4,181
Investment, Identifier [Axis]: Maverick Natural Resources, LLC, Common Equity, Energy—Upstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[23]	138,208
Investments, at fair value	[1],[3],[6],[23]	$ 266,487
Investment, Identifier [Axis]: Maverick Natural Resources, LLC, Common Equity, Upstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[18],[24]					138,208
Investments, at fair value	[2],[4],[11],[18],[24]					$ 312,372
Investment, Identifier [Axis]: Mavis Tire Express Services TopCo, LP, Consumer Discretionary Distribution & Retail
Schedule of Investments [Line Items]
Variable rate	[1],[5]	4.00%		4.00%
Principal amount	[1],[9]	$ 6,982
Amortized Cost	[1]	6,896
Investments, at fair value	[1],[3]	$ 6,932
Investment, Identifier [Axis]: Medallion Midland Acquisition LP, Midstream
Schedule of Investments [Line Items]
Variable rate	[2]					3.75%		3.75%
Principal amount	[2],[14]					$ 7,920
Amortized Cost	[2]					7,886
Investments, at fair value	[2],[4]					7,862
Investment, Identifier [Axis]: Meritage Midstream Services II, LLC, Energy—Midstream
Schedule of Investments [Line Items]
Variable rate	[1],[5]	6.75%		6.75%
Principal amount	[1],[6],[9]	$ 21,857
Amortized Cost	[1],[6]	21,443
Investments, at fair value	[1],[3],[6]	21,440
Investment, Identifier [Axis]: Moss Creek Resources, LLC, Energy—Upstream
Schedule of Investments [Line Items]
Principal amount	[1],[9]	11,693
Amortized Cost	[1]	10,541
Investments, at fair value	[1],[3]	10,750
Investment, Identifier [Axis]: Moss Creek Resources, LLC, Upstream
Schedule of Investments [Line Items]
Principal amount	[2],[14],[18]					11,693
Amortized Cost	[2],[18]					10,358
Investments, at fair value	[2],[4],[18]					10,561
Investment, Identifier [Axis]: NGL Energy Partners, LP, Preferred Equity, Energy—Midstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[8],[16],[32]	157,633
Investments, at fair value	[1],[3],[6],[8],[16],[32]	138,531
Investment, Identifier [Axis]: NGL Energy Partners, LP, Preferred Equity, Midstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[13],[17],[18],[25]					157,633
Investments, at fair value	[2],[4],[11],[13],[17],[18],[25]					125,000
Investment, Identifier [Axis]: NGL Energy Partners, LP, Warrants (Par), Strike: $13.56, Midstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[13],[17],[18]					630
Investments, at fair value	[2],[4],[11],[13],[17],[18]					3
Investment, Identifier [Axis]: NGL Energy Partners, LP, Warrants (Par), Strike: $14.54, Energy—Midstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[8],[16]	3,083
Investments, at fair value	[1],[3],[6],[8],[16]	809
Investment, Identifier [Axis]: NGL Energy Partners, LP, Warrants (Par), Strike: $14.54, Midstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[13],[17],[18]					3,083
Investments, at fair value	[2],[4],[11],[13],[17],[18]					10
Investment, Identifier [Axis]: NGL Energy Partners, LP, Warrants (Par), Strike:$13.56, Energy—Midstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[8],[16]	630
Investments, at fair value	[1],[3],[6],[8],[16]	202
Investment, Identifier [Axis]: NGL Energy Partners, LP, Warrants (Premium), Strike: $16.27, Energy—Midstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[8],[16]	576
Investments, at fair value	[1],[3],[6],[8],[16]	213
Investment, Identifier [Axis]: NGL Energy Partners, LP, Warrants (Premium), Strike: $16.27, Midstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[13],[17],[18]					576
Investments, at fair value	[2],[4],[11],[13],[17],[18]					2
Investment, Identifier [Axis]: NGL Energy Partners, LP, Warrants (Premium), Strike: $17.45, Energy—Midstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[8],[16]	2,623
Investments, at fair value	[1],[3],[6],[8],[16]	886
Investment, Identifier [Axis]: NGL Energy Partners, LP, Warrants (Premium), Strike: $17.45, Midstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[13],[17],[18]					2,623
Investments, at fair value	[2],[4],[11],[13],[17],[18]					8
Investment, Identifier [Axis]: NRG Energy, Inc., Power
Schedule of Investments [Line Items]
Principal amount	[2],[13],[14]					19,125
Amortized Cost	[2],[13]					18,668
Investments, at fair value	[2],[4],[13]					14,401
Investment, Identifier [Axis]: Navios Logistics Finance, Inc., Transportation
Schedule of Investments [Line Items]
Principal amount	[1],[8],[9]	5,000
Amortized Cost	[1],[8]	4,875
Investments, at fair value	[1],[3],[8]	4,830
Investment, Identifier [Axis]: NuStar, Preferred Equity, Energy—Midstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[8]	49,215
Investments, at fair value	[1],[3],[6],[8]	$ 55,433
Investment, Identifier [Axis]: NuStar, Preferred Equity, Midstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[13],[18]					73,114
Investments, at fair value	[2],[4],[11],[13],[18]					$ 83,590
Investment, Identifier [Axis]: OE2 North, LLC, Midstream 1
Schedule of Investments [Line Items]
Variable rate	[2],[11]					5.25%		5.25%
Principal amount	[2],[11],[14]					$ 18,659
Amortized Cost	[2],[11]					18,579
Investments, at fair value	[2],[4],[11]					$ 18,847
Investment, Identifier [Axis]: OE2 North, LLC, Midstream 2
Schedule of Investments [Line Items]
Variable rate	[2],[11],[15]					5.25%		5.25%
Principal amount	[2],[11],[14],[15]					$ 11,341
Amortized Cost	[2],[11],[15]					11,341
Investments, at fair value	[2],[4],[11],[15]					$ 11,455
Investment, Identifier [Axis]: Oryx Midstream Services Permian Basin LLC, Midstream
Schedule of Investments [Line Items]
Variable rate	[2],[18]					3.25%		3.25%
Principal amount	[2],[14],[18]					$ 32,357
Amortized Cost	[2],[18]					32,220
Investments, at fair value	[2],[4],[18]					$ 32,026
Investment, Identifier [Axis]: Parkway Generation LLC, Energy—Power 1
Schedule of Investments [Line Items]
Variable rate	[1],[5]	4.75%		4.75%
Principal amount	[1],[9]	$ 5,760
Amortized Cost	[1]	5,711
Investments, at fair value	[1],[3]	$ 5,631
Investment, Identifier [Axis]: Parkway Generation LLC, Energy—Power 2
Schedule of Investments [Line Items]
Variable rate	[1],[5]	4.75%		4.75%
Principal amount	[1],[9]	$ 43,689
Amortized Cost	[1]	43,317
Investments, at fair value	[1],[3]	42,710
Investment, Identifier [Axis]: Parkway Generation LLC, Power 1
Schedule of Investments [Line Items]
Variable rate	[2]					4.75%		4.75%
Principal amount	[2],[14]					$ 5,760
Amortized Cost	[2]					5,708
Investments, at fair value	[2],[4]					$ 5,700
Investment, Identifier [Axis]: Parkway Generation LLC, Power 2
Schedule of Investments [Line Items]
Variable rate	[2]					4.75%		4.75%
Principal amount	[2],[14]					$ 43,910
Amortized Cost	[2]					43,513
Investments, at fair value	[2],[4]					$ 43,285
Investment, Identifier [Axis]: Peak Exploration & Production, LLC, Upstream 1
Schedule of Investments [Line Items]
Variable rate	[2],[11],[18]					6.75%		6.75%
Principal amount	[2],[11],[14],[18]					$ 13,545
Amortized Cost	[2],[11],[18]					13,528
Investments, at fair value	[2],[4],[11],[18]					$ 13,394
Investment, Identifier [Axis]: Peak Exploration & Production, LLC, Upstream 2
Schedule of Investments [Line Items]
Variable rate	[2],[11],[15]					6.75%		6.75%
Principal amount	[2],[11],[14],[15]					$ 1,505
Amortized Cost	[2],[11],[15]					1,505
Investments, at fair value	[2],[4],[11],[15]					1,488
Investment, Identifier [Axis]: Permian Production Holdings, LLC
Schedule of Investments [Line Items]
Investments, at fair value		4,815				4,767				7,889
Investment, Identifier [Axis]: Permian Production Holdings, LLC, Common Equity
Schedule of Investments [Line Items]
Investments, at fair value		5,710				11,420				8,829
Investment, Identifier [Axis]: Permian Production Holdings, LLC, Common Equity, Energy—Upstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16],[23],[30]	5
Investments, at fair value	[1],[3],[6],[16],[23],[30]	5,710
Investment, Identifier [Axis]: Permian Production Holdings, LLC, Common Equity, Upstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[18],[24],[31]					5
Investments, at fair value	[2],[4],[11],[18],[24],[31]					11,420
Investment, Identifier [Axis]: Permian Production Holdings, LLC, Energy—Upstream
Schedule of Investments [Line Items]
Principal amount	[1],[6],[9],[30]	4,815
Amortized Cost	[1],[6],[30]	4,379
Investments, at fair value	[1],[3],[6],[30]	$ 4,815
Investment, Identifier [Axis]: Permian Production Holdings, LLC, Upstream
Schedule of Investments [Line Items]
Principal amount	[2],[11],[14],[18],[31]					4,767
Amortized Cost	[2],[11],[18],[31]					4,266
Investments, at fair value	[2],[4],[11],[18],[31]					4,767
Investment, Identifier [Axis]: Permian Resources Operating LLC, Upstream 1
Schedule of Investments [Line Items]
Principal amount	[2],[14]					26,365
Amortized Cost	[2]					27,511
Investments, at fair value	[2],[4]					25,703
Investment, Identifier [Axis]: Permian Resources Operating LLC, Upstream 2
Schedule of Investments [Line Items]
Principal amount	[2],[14],[18]					5,200
Amortized Cost	[2],[18]					5,257
Investments, at fair value	[2],[4],[18]					$ 4,473
Investment, Identifier [Axis]: Pinnacle Midland Gas Holdco LLC, Energy—Midstream
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6]	6.75%		6.75%
Principal amount	[1],[6],[9]	$ 9,370
Amortized Cost	[1],[6]	9,338
Investments, at fair value	[1],[3],[6]	9,294
Investment, Identifier [Axis]: Pinnacle Midland Gas Holdco LLC, Midstream 1
Schedule of Investments [Line Items]
Variable rate	[2],[11]					6.75%		6.75%
Principal amount	[2],[11],[14]					$ 9,370
Amortized Cost	[2],[11]					9,304
Investments, at fair value	[2],[4],[11]					$ 9,310
Investment, Identifier [Axis]: Pinnacle Midland Gas Holdco LLC, Midstream 2
Schedule of Investments [Line Items]
Variable rate	[2],[11],[15]					6.75%		6.75%
Principal amount	[2],[11],[14],[15]					$ 2,477
Amortized Cost	[2],[11],[15]					2,477
Investments, at fair value	[2],[4],[11],[15]					2,461
Investment, Identifier [Axis]: Plainfield Renewable Energy Holdings LLC, Energy—Power 1
Schedule of Investments [Line Items]
Principal amount	[1],[6],[9],[16],[32]	13,297
Amortized Cost	[1],[6],[16],[32]	12,329
Investments, at fair value	[1],[3],[6],[16],[32]	9,565
Investment, Identifier [Axis]: Plainfield Renewable Energy Holdings LLC, Energy—Power 2
Schedule of Investments [Line Items]
Principal amount	[1],[6],[9],[16],[32]	4,015
Amortized Cost	[1],[6],[16],[32]	3,827
Investments, at fair value	[1],[3],[6],[16],[32]	0
Investment, Identifier [Axis]: Plainfield Renewable Energy Holdings LLC, Letter of Credit, Energy—Power
Schedule of Investments [Line Items]
Principal amount	[1],[6],[9],[10]	2,709
Amortized Cost	[1],[6],[10]	2,709
Investments, at fair value	[1],[3],[6],[10]	$ 0
Investment, Identifier [Axis]: Plainfield Renewable Energy Holdings LLC, Letter of Credit, Power
Schedule of Investments [Line Items]
Principal amount	[2],[11],[14],[15]					2,709
Amortized Cost	[2],[11],[15]					2,709
Investments, at fair value	[2],[4],[11],[15]					0
Investment, Identifier [Axis]: Plainfield Renewable Energy Holdings LLC, Power 1
Schedule of Investments [Line Items]
Principal amount	[2],[11],[14],[18]					12,121
Amortized Cost	[2],[11],[18]					12,121
Investments, at fair value	[2],[4],[11],[18]					9,997
Investment, Identifier [Axis]: Plainfield Renewable Energy Holdings LLC, Power 2
Schedule of Investments [Line Items]
Principal amount	[2],[11],[14],[18]					3,643
Amortized Cost	[2],[11],[18]					3,643
Investments, at fair value	[2],[4],[11],[18]					$ 0
Investment, Identifier [Axis]: Potomac Energy Center, LLC, Energy—Power
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6]	6.00%		6.00%
Principal amount	[1],[6],[9]	$ 58,164
Amortized Cost	[1],[6]	57,313
Investments, at fair value	[1],[3],[6]	53,753
Investment, Identifier [Axis]: Potomac Energy Center, LLC, Power
Schedule of Investments [Line Items]
Variable rate	[2],[11]					6.00%		6.00%
Principal amount	[2],[11],[14]					$ 58,459
Amortized Cost	[2],[11]					57,508
Investments, at fair value	[2],[4],[11]					58,443
Investment, Identifier [Axis]: Ranger Oil Corp., Upstream
Schedule of Investments [Line Items]
Principal amount	[2],[13],[14]					29,772
Amortized Cost	[2],[13]					29,633
Investments, at fair value	[2],[4],[13]					29,678
Investment, Identifier [Axis]: Ridgeback Resources Inc., Common Equity
Schedule of Investments [Line Items]
Investments, at fair value		0				41,851				48,356
Investment, Identifier [Axis]: Ridgeback Resources Inc., Common Equity, Upstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[13],[18],[31],[33]					46,599
Investments, at fair value	[2],[4],[11],[13],[18],[31],[33]					41,851
Investment, Identifier [Axis]: ST EIP Holdings Inc., Energy—Midstream
Schedule of Investments [Line Items]
Principal amount	[1],[6],[9]	10,473
Amortized Cost	[1],[6]	10,037
Investments, at fair value	[1],[3],[6]	10,015
Investment, Identifier [Axis]: ST EIP Holdings Inc., Midstream
Schedule of Investments [Line Items]
Principal amount	[2],[11],[14]					10,526
Amortized Cost	[2],[11]					10,064
Investments, at fair value	[2],[4],[11]					10,074
Investment, Identifier [Axis]: Saturn Oil & Gas Inc., Common Equity, Energy—Upstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[8],[16],[34]	3,052
Investments, at fair value	[1],[3],[8],[16],[34]	$ 2,674
Investment, Identifier [Axis]: Segreto Power Holdings, LLC, Preferred Equity, Power
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18],[24],[25]					99,766
Investments, at fair value	[2],[4],[11],[17],[18],[24],[25]					$ 83,647
Investment, Identifier [Axis]: SilverBow Resources, Inc., Energy—Upstream
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6],[8]	7.50%		7.50%
Principal amount	[1],[6],[8],[9]	$ 14,250
Amortized Cost	[1],[6],[8]	14,211
Investments, at fair value	[1],[3],[6],[8]	$ 14,313
Investment, Identifier [Axis]: SilverBow Resources, Inc., Upstream
Schedule of Investments [Line Items]
Variable rate	[2],[11],[13],[18]					7.50%		7.50%
Principal amount	[2],[11],[13],[14],[18]					$ 14,250
Amortized Cost	[2],[11],[13],[18]					14,199
Investments, at fair value	[2],[4],[11],[13],[18]					$ 14,322
Investment, Identifier [Axis]: Sitio Royalties Operating Partnership, LP, Energy—Upstream
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6],[8]	5.75%		5.75%
Principal amount	[1],[6],[8],[9]	$ 18,500
Amortized Cost	[1],[6],[8]	18,350
Investments, at fair value	[1],[3],[6],[8]	18,289
Investment, Identifier [Axis]: Sitio Royalties Operating Partnership, LP, Upstream
Schedule of Investments [Line Items]
Variable rate	[2],[11],[13],[18]					6.50%		6.50%
Principal amount	[2],[11],[13],[14],[18]					$ 19,500
Amortized Cost	[2],[11],[13],[18]					19,318
Investments, at fair value	[2],[4],[11],[13],[18]					19,256
Investment, Identifier [Axis]: Suburban Propane Partners LP, Midstream
Schedule of Investments [Line Items]
Principal amount	[2],[13],[14],[18]					7,590
Amortized Cost	[2],[13],[18]					7,837
Investments, at fair value	[2],[4],[13],[18]					6,461
Investment, Identifier [Axis]: Sustainable Infrastructure Investments, LLC 2
Schedule of Investments [Line Items]
Investments, at fair value		50,149				51,098				50,770
Investment, Identifier [Axis]: Sustainable Infrastructure Investments, LLC, Energy—Power
Schedule of Investments [Line Items]
Principal amount	[1],[6],[8],[9],[16],[21]	60,603
Amortized Cost	[1],[6],[8],[16],[21]	54,514
Investments, at fair value	[1],[3],[6],[8],[16],[21]	$ 50,149
Investment, Identifier [Axis]: Sustainable Infrastructure Investments, LLC, Power
Schedule of Investments [Line Items]
Principal amount	[2],[11],[22],[35]					60,603
Amortized Cost	[2],[11],[22],[35]					54,514
Investments, at fair value	[2],[4],[11],[22],[35]					51,098
Investment, Identifier [Axis]: Swift Worldwide Resources Holdco Limited, Common Equity, Service & Equipment
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[13],[17],[18],[36]					6,029
Investments, at fair value	[2],[4],[11],[13],[17],[18],[36]					3,131
Investment, Identifier [Axis]: TKC Holdings, Inc., Consumer Staples Distribution & Retail
Schedule of Investments [Line Items]
Variable rate	[1],[5]	5.50%		5.50%
Principal amount	[1],[9]	$ 4,747
Amortized Cost	[1]	4,439
Investments, at fair value	[1],[3]	4,467
Investment, Identifier [Axis]: Tallgrass Energy Partners, LP, Midstream
Schedule of Investments [Line Items]
Principal amount	[2],[14],[18]					19,761
Amortized Cost	[2],[18]					19,676
Investments, at fair value	[2],[4],[18]					18,480
Investment, Identifier [Axis]: Telpico, LLC, Common Equity
Schedule of Investments [Line Items]
Investments, at fair value		0				0				0
Investment, Identifier [Axis]: Telpico, LLC, Common Equity, Energy—Upstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16],[23],[30]	0
Investments, at fair value	[1],[3],[6],[16],[23],[30]	0
Investment, Identifier [Axis]: Telpico, LLC, Common Equity, Upstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18],[24],[31]					0
Investments, at fair value	[2],[4],[11],[17],[18],[24],[31]					0
Investment, Identifier [Axis]: Tenrgys, LLC, Common Equity, Energy—Upstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16],[23]	7,571
Investments, at fair value	[1],[3],[6],[16],[23]	$ 4,531
Investment, Identifier [Axis]: Tenrgys, LLC, Common Equity, Upstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18],[24]					7,571
Investments, at fair value	[2],[4],[11],[17],[18],[24]					$ 6,801
Investment, Identifier [Axis]: Tenrgys, LLC, Energy—Upstream
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6]	7.50%		7.50%
Principal amount	[1],[6],[9]	$ 20,537
Amortized Cost	[1],[6]	20,537
Investments, at fair value	[1],[3],[6]	$ 19,613
Investment, Identifier [Axis]: Tenrgys, LLC, Upstream
Schedule of Investments [Line Items]
Variable rate	[2],[11],[18]					7.50%		7.50%
Principal amount	[2],[11],[14],[18]					$ 20,537
Amortized Cost	[2],[11],[18]					20,537
Investments, at fair value	[2],[4],[11],[18]					$ 20,537
Investment, Identifier [Axis]: Traverse Midstream Partners LLC, Midstream
Schedule of Investments [Line Items]
Variable rate	[2]					4.25%		4.25%
Principal amount	[2],[14]					$ 28,436
Amortized Cost	[2]					28,484
Investments, at fair value	[2],[4]					28,418
Investment, Identifier [Axis]: TruGreen, LP, Commercial & Professional Services
Schedule of Investments [Line Items]
Variable rate	[1],[5]	4.00%		4.00%
Principal amount	[1],[9]	$ 4,987
Amortized Cost	[1]	4,551
Investments, at fair value	[1],[3]	4,603
Investment, Identifier [Axis]: USA Compression Partners, LP, Common Equity, Energy—Midstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[8]	1,617
Investments, at fair value	[1],[3],[8]	1,673
Investment, Identifier [Axis]: USA Compression Partners, LP, Common Equity, Midstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[13],[17],[18]					1,617
Investments, at fair value	[2],[4],[13],[17],[18]					1,655
Investment, Identifier [Axis]: USA Compression Partners, LP, Preferred Equity, Energy—Midstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[8]	78,041
Investments, at fair value	[1],[3],[6],[8]	88,850
Investment, Identifier [Axis]: USA Compression Partners, LP, Preferred Equity, Midstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11]					77,943
Investments, at fair value	[2],[4],[11]					90,479
Investment, Identifier [Axis]: USA Compression Partners, LP, Warrants (Premium), Strike: $19.59, Energy—Midstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[8],[16]	714
Investments, at fair value	[1],[3],[6],[8],[16]	4,990
Investment, Identifier [Axis]: USA Compression Partners, LP, Warrants (Premium), Strike: $19.59, Midstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[13],[17],[18]					714
Investments, at fair value	[2],[4],[11],[13],[17],[18]					5,711
Investment, Identifier [Axis]: Warren Resources, Inc.
Schedule of Investments [Line Items]
Investments, at fair value		23,703				23,584				23,688
Investment, Identifier [Axis]: Warren Resources, Inc., Common Equity
Schedule of Investments [Line Items]
Investments, at fair value		29,431				36,982				$ 25,854
Investment, Identifier [Axis]: Warren Resources, Inc., Common Equity, Energy—Upstream
Schedule of Investments [Line Items]
Amortized Cost	[1],[6],[16],[21]	20,754
Investments, at fair value	[1],[3],[6],[16],[21]	$ 29,431
Investment, Identifier [Axis]: Warren Resources, Inc., Common Equity, Upstream
Schedule of Investments [Line Items]
Amortized Cost	[2],[11],[17],[18],[22]					20,754
Investments, at fair value	[2],[4],[11],[17],[18],[22]					$ 36,982
Investment, Identifier [Axis]: Warren Resources, Inc., Energy—Upstream
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6],[21]	9.00%		9.00%
Principal amount	[1],[6],[9],[21]	$ 23,703
Amortized Cost	[1],[6],[21]	23,703
Investments, at fair value	[1],[3],[6],[21]	$ 23,703
Investment, Identifier [Axis]: Warren Resources, Inc., Upstream
Schedule of Investments [Line Items]
Variable rate	[2],[11],[22]					9.00%		9.00%
Principal amount	[2],[11],[14],[22]					$ 23,584
Amortized Cost	[2],[11],[22]					23,584
Investments, at fair value	[2],[4],[11],[22]					$ 23,584
Investment, Identifier [Axis]: Wattbridge Inc., Energy—Power
Schedule of Investments [Line Items]
Variable rate	[1],[5],[6]	9.85%		9.85%
Principal amount	[1],[6],[9]	$ 42,938
Amortized Cost	[1],[6]	42,938
Investments, at fair value	[1],[3],[6]	41,568
Investment, Identifier [Axis]: Wattbridge Inc., Power
Schedule of Investments [Line Items]
Variable rate	[2],[11]					7.85%		7.85%
Principal amount	[2],[11],[14]					$ 42,500
Amortized Cost	[2],[11]					42,500
Investments, at fair value	[2],[4],[11]					41,880
Sustainable Infrastructure Investments, LLC
Schedule of Investments [Line Items]
Principal amount		264,692				274,088
Amortized Cost		264,692				274,088
Investments, at fair value		$ 267,244				$ 275,058
Percent of net assets		100.00%		100.00%		100.00%		100.00%
Sustainable Infrastructure Investments, LLC | London Interbank Offered Rate (LIBOR)
Schedule of Investments [Line Items]
Variable rate		5.55%		5.55%		4.77%		4.77%
Sustainable Infrastructure Investments, LLC | Canadian Dollar Offer Rate
Schedule of Investments [Line Items]
Variable rate		5.40%		5.40%		4.94%		4.94%
Sustainable Infrastructure Investments, LLC | Net Senior Secured Loans—First Lien
Schedule of Investments [Line Items]
Amortized Cost		$ 264,692				$ 274,088
Investments, at fair value		$ 267,244				$ 275,058
Percent of net assets		100.00%		100.00%		100.00%		100.00%
Sustainable Infrastructure Investments, LLC | Investment, Identifier [Axis]: Alianca Transportadora de Gas Participacoes S.A., Midstream
Schedule of Investments [Line Items]
Variable rate		2.85%		2.85%		2.60%		2.60%
Principal amount		$ 70,610				$ 73,707
Amortized Cost		70,610				73,707
Investments, at fair value		$ 72,560				$ 74,601
Sustainable Infrastructure Investments, LLC | Investment, Identifier [Axis]: Blue Heron Intermediate Holdco I, LLC, Midstream
Schedule of Investments [Line Items]
Variable rate		1.88%		1.88%		1.88%		1.88%
Principal amount		$ 31,244				$ 31,832
Amortized Cost		31,244				31,832
Investments, at fair value		$ 31,352				$ 31,885
Sustainable Infrastructure Investments, LLC | Investment, Identifier [Axis]: Cedar Creek II LLC, Renewables
Schedule of Investments [Line Items]
Variable rate		1.88%		1.88%		1.88%		1.88%
Principal amount		$ 8,160				$ 8,710
Amortized Cost		8,160				8,710
Investments, at fair value		$ 8,177				$ 8,722
Sustainable Infrastructure Investments, LLC | Investment, Identifier [Axis]: Copper Mountain Solar 3, LLC, Renewables
Schedule of Investments [Line Items]
Variable rate		1.88%		1.88%		1.75%		1.75%
Principal amount		$ 17,105				$ 17,804
Amortized Cost		17,105				17,804
Investments, at fair value		$ 17,221				$ 17,879
Sustainable Infrastructure Investments, LLC | Investment, Identifier [Axis]: FLNG Liquefaction 2, LLC, Midstream
Schedule of Investments [Line Items]
Variable rate		1.50%		1.50%		1.50%		1.50%
Principal amount		$ 27,375				$ 28,170
Amortized Cost		27,375				28,170
Investments, at fair value		27,303				27,990
Sustainable Infrastructure Investments, LLC | Investment, Identifier [Axis]: Largest Portfolio Company Investment
Schedule of Investments [Line Items]
Principal amount		$ 70,610				$ 73,707
Sustainable Infrastructure Investments, LLC | Investment, Identifier [Axis]: Meikle Wind Energy, LP, Renewables
Schedule of Investments [Line Items]
Variable rate		1.50%		1.50%		1.50%		1.50%
Principal amount				$ 15,471				$ 16,030
Amortized Cost		$ 11,903				$ 12,332
Investments, at fair value		$ 11,611				$ 11,873
Sustainable Infrastructure Investments, LLC | Investment, Identifier [Axis]: NES Hercules Class B Member, LLC, Renewables
Schedule of Investments [Line Items]
Variable rate		1.65%		1.65%		1.50%		1.50%
Principal amount		$ 24,317				$ 24,487
Amortized Cost		24,317				24,487
Investments, at fair value		$ 24,847				$ 24,954
Sustainable Infrastructure Investments, LLC | Investment, Identifier [Axis]: ST EIP Holdco LLC, Midstream
Schedule of Investments [Line Items]
Variable rate		2.50%		2.50%		2.50%		2.50%
Principal amount		$ 58,124				$ 58,673
Amortized Cost		58,124				58,673
Investments, at fair value		$ 57,900				$ 58,288
Sustainable Infrastructure Investments, LLC | Investment, Identifier [Axis]: Seine Funding, LLC
Schedule of Investments [Line Items]
Variable rate												1.20%
Principal amount												$ 634,103
Sustainable Infrastructure Investments, LLC | Investment, Identifier [Axis]: Top of the World Wind Energy LLC, Renewables
Schedule of Investments [Line Items]
Variable rate		1.88%		1.88%		1.88%		1.88%
Principal amount		$ 15,854				$ 18,373
Amortized Cost		15,854				18,373
Investments, at fair value		$ 16,273				$ 18,866

[1] Security may be an obligation of one or more entities affiliated with the named company.

[2] Security may be an obligation of one or more entities affiliated with the named company.

[3] See Note 8 for additional information regarding the fair value of the Company’s financial instruments.

[4] See Note 8 for additional information regarding the fair value of the Company’s financial instruments.

[5] Certain variable rate securities in the Company’s portfolio bear interest at a rate determined by a publicly disclosed base rate plus a basis point spread. As of June 30, 2023, the three-month London Interbank Offered Rate, or LIBOR, or L, was 5.55% and the Secured Overnight Financing Rate, or SOFR, or S, was 5.27%. PIK means paid-in-kind. PIK income accruals may be adjusted based on the fair value of the underlying investment. Variable rate securities with no floor rate use the respective benchmark rate in all cases.

[6] Security is classified as Level 3 in the Company’s fair value hierarchy (see Note 8).

[7] Security or portion thereof held within FS Power Investments II, LLC, a wholly-owned subsidiary of the Company.

[8] The investment is not a qualifying asset under the Investment Company Act of 1940, as amended, or the 1940 Act. A business development company may not acquire any asset other than a qualifying asset, unless, at the time the acquisition is made, qualifying assets represent at least 70% of the business development company’s total assets. As of June 30, 2023, 73.7% of the Company’s total assets represented qualifying assets.

[9] Denominated in U.S. dollars, unless otherwise noted.

[10] Security is an unfunded commitment. The stated rate reflects the spread disclosed at the time of commitment and may not indicate the actual rate received upon funding.

[11] Security is classified as Level 3 in the Company’s fair value hierarchy (see Note 8).

[12] Security or portion thereof held within FS Power Investments II, LLC, a wholly-owned subsidiary of the Company.

[13] The investment is not a qualifying asset under the Investment Company Act of 1940, as amended, or the 1940 Act. A business development company may not acquire any asset other than a qualifying asset, unless, at the time the acquisition is made, qualifying assets represent at least 70% of the business development company’s total assets. As of December 31, 2022, 77.5% of the Company’s total assets represented qualifying assets.

[14] Denominated in U.S. dollars, unless otherwise noted.

[15] Security is an unfunded commitment. The stated rate reflects the spread disclosed at the time of commitment and may not indicate the actual rate received upon funding.

[16] Security is non-income producing.

[17] Security is non-income producing.

[18] Security or portion thereof is pledged as collateral supporting the amounts outstanding under the Senior Secured Notes with JPMorgan Chase Bank, N.A. (see Note 9).

[19] (4)    Security includes a partially unfunded commitment with amortized cost of $2,500 and fair value of $2,500.

[20] Security includes a partially unfunded commitment with amortized cost of $2,500 and fair value of $2,500.

[21] Under the 1940 Act, the Company generally is deemed to “control” a portfolio company if it owns more than 25% of the portfolio company’s voting securities or it has the power to exercise control over the management or policies of such portfolio company. As of June 30, 2023, the Company held investments in portfolio companies of which it is deemed to be an “affiliated person” of and deemed to “control.” The following table presents certain information with respect to investments in portfolio companies of which the Company was deemed to be an affiliated person and deemed to control as of June 30, 2023: Portfolio Company Fair Value at December 31, 2022 Gross Additions(1) Gross Reductions(2) Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation) Fair Value at June 30, 2023 Interest Income(3) PIK Income(3) Senior Secured Loans—First Lien Allied Downhole Technologies, LLC(4) $8,436 $113 $(996)$— $— $7,553 $207 $113 Allied Wireline Services, LLC63,888 6,389 — — — 70,277 3,223 — Warren Resources, Inc.23,584 119 — — — 23,703 1,648 119 Sustainable Infrastructure Investments, LLCSustainable Infrastructure Investments, LLC51,098 — — — (949)50,149 — — Equity/OtherAllied Wireline Services, LLC, Common Equity10,463 — — — (2,395)8,068 — — Allied Wireline Services, LLC, Warrants— — — — — — — — Warren Resources, Inc., Common Equity36,982 — — — (7,551)29,431 — — $194,451 $6,621 $(996)$— $(10,895)$189,181 $5,078 $232  _____________ (1)    Gross additions may include increases in the cost basis of investments resulting from new portfolio investments, PIK interest, the amortization of unearned income, the exchange of one or more existing securities for one or more new securities and/or the movement of an existing portfolio company into this category from a different category. (2)    Gross reductions may include decreases in the cost basis of investments resulting from principal collections related to investment repayments or sales, the exchange of one or more existing securities for one or more new securities and/or the movement of an existing portfolio company out of this category into a different category. (3)    Interest and PIK income presented for the six months ended June 30, 2023. (4)    Security includes a partially unfunded commitment with amortized cost of $2,500 and fair value of $2,500.

[22] Under the 1940 Act, the Company generally is deemed to “control” a portfolio company if it owns more than 25% of the portfolio company’s voting securities or it has the power to exercise control over the management or policies of such portfolio company. As of December 31, 2022, the Company held investments in portfolio companies of which it is deemed to be an “affiliated person” of and deemed to “control.” The following table presents certain information with respect to investments in portfolio companies of which the Company was deemed to be an affiliated person and deemed to control as of December 31, 2022: Portfolio Company Fair Value at December 31, 2021 Gross Additions(1) Gross Reductions(2) Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation) Fair Value at December 31, 2022 Interest Income(3) PIK Income(3) Dividend Income(3) Senior Secured Loans—First Lien Allied Downhole Technologies, LLC(4) $7,782 $654 $— $— $— $8,436 $— $654 $— Allied Wireline Services, LLC46,339 5,808 — — 11,741 63,888 316 5,808 — MECO IV Holdco, LLC22,745 455 (23,200)— — — — 455 — Warren Resources, Inc.23,688 237 (341)— — 23,584 2,620 237 — Sustainable Infrastructure Investments, LLCSustainable Infrastructure Investments, LLC50,770 — — — 328 51,098 — — 735 Equity/OtherAllied Wireline Services, LLC, Common Equity— — — — 10,463 10,463 — — — Allied Wireline Services, LLC, Warrants— — — — — — — — — MECO IV Holdco, LLC, Class A-1 Units4,181 — (18,060)15,899 (2,020)— — — — Warren Resources, Inc., Common Equity25,854 — — — 11,128 36,982 — — — $181,359 $7,154 $(41,601)$15,899 $31,640 $194,451 $2,936 $7,154 $735  _____________ (1)    Gross additions may include increases in the cost basis of investments resulting from new portfolio investments, PIK interest, the amortization of unearned income, the exchange of one or more existing securities for one or more new securities and/or the movement of an existing portfolio company into this category from a different category. (2)    Gross reductions may include decreases in the cost basis of investments resulting from principal collections related to investment repayments or sales, the exchange of one or more existing securities for one or more new securities and/or the movement of an existing portfolio company out of this category into a different category. (3)    Interest, PIK and dividend income presented for the year ended December 31, 2022. (4)    Security includes a partially unfunded commitment with amortized cost of $2,500 and fair value of $2,500.

[23] Security held within FSEP Investments, Inc., a wholly-owned subsidiary of the Company.

[24] Security held within FSEP Investments, Inc., a wholly-owned subsidiary of the Company.

[25] Security was on non-accrual status as of December 31, 2022.

[26] Investment is a real property interest and is included with Senior Secured Loans—First Lien to facilitate comparison with other investments.

[27] Security held within EP Northern Investments, LLC, a wholly-owned subsidiary of the Company.

[28] Investment is a real property interest and is included with Senior Secured Loans—First Lien to facilitate comparison with other investments.

[29] Security held within EP Northern Investments, LLC, a wholly-owned subsidiary of the Company.

[30] Under the 1940 Act, the Company generally is deemed to be an “affiliated person” of a portfolio company if it owns 5% or more of the portfolio company’s voting securities and generally is deemed to “control” a portfolio company if it owns more than 25% of the portfolio company’s voting securities or it has the power to exercise control over the management or policies of such portfolio company. As of June 30, 2023, the Company held investments in portfolio companies of which it is deemed to be an “affiliated person” but is not deemed to “control”. The following table presents certain information with respect to investments in portfolio companies of which the Company was deemed to be an affiliated person as of June 30, 2023: Portfolio Company Fair Value at December 31, 2022 Gross Additions(1) Gross Reductions(2) Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation) Fair Value at June 30, 2023 Interest Income(3) PIK Income(3) Senior Secured Loans—First LienPermian Production Holdings, LLC$4,767 $113 $— $— $(65)$4,815 $324 $48 Equity/OtherGWP Midstream Holdco, LLC, Common Equity5,044 — — — (3,659)1,385 — — Harvest Oil & Gas Corp., Common Equity810 — (641)— 641 810 — — Limetree Bay Energy, LLC, Class A Units1,885 83 — (21,541)19,573 — — — Permian Production Holdings, LLC, Common Equity11,420 — — — (5,710)5,710 — — Ridgeback Resources Inc., Common Equity41,851 — (35,240)(11,359)4,748 — — — Telpico, LLC, Common Equity— — — — — — — — $65,777 $196 $(35,881)$(32,900)$15,528 $12,720 $324 $48  _____________ (1)    Gross additions may include increases in the cost basis of investments resulting from new portfolio investments, PIK interest, the amortization of unearned income, the exchange of one or more existing securities for one or more new securities and/or the movement of an existing portfolio company into this category from a different category. (2)    Gross reductions may include decreases in the cost basis of investments resulting from principal collections related to investment repayments or sales, the exchange of one or more existing securities for one or more new securities and/or the movement of an existing portfolio company out of this category into a different category. (3)    Interest and PIK income presented for the six months ended June 30, 2023.

[31] Under the 1940 Act, the Company generally is deemed to be an “affiliated person” of a portfolio company if it owns 5% or more of the portfolio company’s voting securities and generally is deemed to “control” a portfolio company if it owns more than 25% of the portfolio company’s voting securities or it has the power to exercise control over the management or policies of such portfolio company. As of December 31, 2022, the Company held investments in portfolio companies of which it is deemed to be an “affiliated person” but is not deemed to “control”. The following table presents certain information with respect to investments in portfolio companies of which the Company was deemed to be an affiliated person as of December 31, 2022: Portfolio Company Fair Value at December 31, 2021 Gross Additions(1) Gross Reductions(2) Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation) Fair Value at December 31, 2022 Interest Income(3) PIK Income(3) Fee Income(3) Dividend Income(3) Senior Secured Loans—First LienLimetree Bay Energy, LLC$3,166 $— $(1,587)$(12,756)$11,177 $— $— $— $— $— Permian Production Holdings, LLC7,889 697 (3,674)551 (696)4,767 570 105 — — Senior Secured BondsGreat Western Petroleum, LLC58,055 96 (55,096)1,087 (4,142)— 2,649 — 7,268 — Equity/OtherGreat Western Petroleum, LLC, Common Equity40,731 — (84,871)54,081 (9,941)— — — — — GWP Midstream Holdco, LLC, Common Equity— 6,681 — — (1,637)5,044 — — — — Harvest Oil & Gas Corp., Common Equity2,836 — (743)— (1,283)810 — — — — Limetree Bay Energy, LLC, Class A Units6,046 1,795 — — (5,956)1,885 — — — — Permian Production Holdings, LLC, Common Equity8,829 4 — — 2,587 11,420 — — — 1,726 Ridgeback Resources Inc., Common Equity48,356 — (12,559)173 5,881 41,851 — — — 3,691 Telpico, LLC, Common Equity— — — — — — — — — — $175,908 $9,273 $(158,530)$43,136 $(4,010)$65,777 $3,219 $105 $7,268 $5,417  _____________ (1)    Gross additions may include increases in the cost basis of investments resulting from new portfolio investments, PIK interest, the amortization of unearned income, the exchange of one or more existing securities for one or more new securities and/or the movement of an existing portfolio company into this category from a different category. (2)    Gross reductions may include decreases in the cost basis of investments resulting from principal collections related to investment repayments or sales, the exchange of one or more existing securities for one or more new securities and/or the movement of an existing portfolio company out of this category into a different category. (3)    Interest, PIK, fee and dividend income presented for the year ended December 31, 2022.

[32] Security was on non-accrual status as of June 30, 2023.

[33] Investment denominated in Canadian dollars. Amortized cost and fair value are converted into U.S. dollars as of December 31, 2022.

[34] Investment denominated in Canadian dollars. Amortized cost and fair value are converted into U.S. dollars as of June 30, 2023.

[35] Includes the effect of swap contracts.

[36] Investment denominated in British pounds. Amortized cost and fair value are converted into U.S. dollars as of December 31, 2022.