Commitment and Contingencies - Unfunded Commitments (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	$ 205,318	$ 324,010	$ 334,170
Fair Value of Unfunded Commitment Liability	2,961	5,463
Investment, Identifier [Axis]: Activehours, Inc. (d/b/a Earnin)
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	5,000	5,000
Fair Value of Unfunded Commitment Liability	68	68
Investment, Identifier [Axis]: Athletic Greens (USA), Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	20,000	20,000
Fair Value of Unfunded Commitment Liability	112	112
Investment, Identifier [Axis]: Avantstay, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	5,000	5,000
Fair Value of Unfunded Commitment Liability	0	0
Investment, Identifier [Axis]: Baby Generation, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	23	1,417
Fair Value of Unfunded Commitment Liability	1	47
Investment, Identifier [Axis]: Belong Home, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	9,718
Fair Value of Unfunded Commitment Liability	0	197
Investment, Identifier [Axis]: Corelight, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	22,857	22,857
Fair Value of Unfunded Commitment Liability	123	122
Investment, Identifier [Axis]: Dia Styling Co.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	5,000
Fair Value of Unfunded Commitment Liability	0	0
Investment, Identifier [Axis]: Don't Run Out, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	1,499	1,499
Fair Value of Unfunded Commitment Liability	95	95
Investment, Identifier [Axis]: FlashParking, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	1,000	1,000
Fair Value of Unfunded Commitment Liability	10	10
Investment, Identifier [Axis]: Flo Health, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	15,000
Fair Value of Unfunded Commitment Liability	0	422
Investment, Identifier [Axis]: Foodology Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	3,000	0
Fair Value of Unfunded Commitment Liability	0	0
Investment, Identifier [Axis]: Found Health, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	16,790	25,000
Fair Value of Unfunded Commitment Liability	392	585
Investment, Identifier [Axis]: Frubana Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	20,000	30,000
Fair Value of Unfunded Commitment Liability	415	603
Investment, Identifier [Axis]: Homeward, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	1,400	0
Fair Value of Unfunded Commitment Liability	9	0
Investment, Identifier [Axis]: JOKR S.à r.l.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	12,750
Fair Value of Unfunded Commitment Liability	0	487
Investment, Identifier [Axis]: Jerry Services, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	12,500	12,500
Fair Value of Unfunded Commitment Liability	574	573
Investment, Identifier [Axis]: Kalderos, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	10,000	10,000
Fair Value of Unfunded Commitment Liability	242	242
Investment, Identifier [Axis]: LeoLabs, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	12,000	12,000
Fair Value of Unfunded Commitment Liability	263	263
Investment, Identifier [Axis]: Loft Orbital Solutions Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	5,000	5,000
Fair Value of Unfunded Commitment Liability	0	0
Investment, Identifier [Axis]: Lower Holding Company
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	7,020	10,000
Fair Value of Unfunded Commitment Liability	176	250
Investment, Identifier [Axis]: McN Investments Ltd.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	3,000	8,000
Fair Value of Unfunded Commitment Liability	74	218
Investment, Identifier [Axis]: Medly Health Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	13,000
Fair Value of Unfunded Commitment Liability	0	214
Investment, Identifier [Axis]: Merama Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	3,720	7,976
Fair Value of Unfunded Commitment Liability	0	82
Investment, Identifier [Axis]: Minted, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	2,000	4,000
Fair Value of Unfunded Commitment Liability	94	94
Investment, Identifier [Axis]: Mynd Management, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	1,000	1,000
Fair Value of Unfunded Commitment Liability	16	16
Investment, Identifier [Axis]: Mystery Tackle Box, Inc. (d/b/a Catch Co.)
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	3,490
Fair Value of Unfunded Commitment Liability	0	98
Investment, Identifier [Axis]: NewStore Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	1,000	1,000
Fair Value of Unfunded Commitment Liability	16	16
Investment, Identifier [Axis]: Open Space Labs, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	2,500
Fair Value of Unfunded Commitment Liability	0	34
Investment, Identifier [Axis]: Overtime Sports, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	20,000	20,000
Fair Value of Unfunded Commitment Liability	185	185
Investment, Identifier [Axis]: Pair EyeWear, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	2,167
Fair Value of Unfunded Commitment Liability	0	38
Investment, Identifier [Axis]: Project 1920, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	1,000
Fair Value of Unfunded Commitment Liability	0	0
Investment, Identifier [Axis]: Quick Commerce Ltd
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	1,000	1,000
Fair Value of Unfunded Commitment Liability	13	13
Investment, Identifier [Axis]: RenoRun US Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	10,000	10,000
Fair Value of Unfunded Commitment Liability	83	83
Investment, Identifier [Axis]: Savage X, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	10,000	10,000
Fair Value of Unfunded Commitment Liability	0	0
Investment, Identifier [Axis]: Substack Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	2,036
Fair Value of Unfunded Commitment Liability	0	61
Investment, Identifier [Axis]: Tempo Interactive Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	1,000
Fair Value of Unfunded Commitment Liability	0	0
Investment, Identifier [Axis]: The Aligned Company (f/k/a Thingy Thing Inc.)
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	5,509	5,100
Fair Value of Unfunded Commitment Liability	0	0
Investment, Identifier [Axis]: The Pill Club Holdings, Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	0
Fair Value of Unfunded Commitment Liability	0	59
Investment, Identifier [Axis]: True Footage Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	0	12,000
Fair Value of Unfunded Commitment Liability	0	12
Investment, Identifier [Axis]: Vial Health Technology Inc.
Financial Support for Nonconsolidated Legal Entity [Line Items]
Unfunded Commitments	5,000	15,000
Fair Value of Unfunded Commitment Liability	$ 0	$ 164