Investment Valuations and Fair Value Measurements - Summary of Reconciliation of Balances for Total Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Investment Valuations And Fair Value Measurements [Line Items]
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Realized Investment Gains (Losses)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Unrealized Gain (Loss) on Investments	Unrealized Gain (Loss) on Investments
Fair Value, Inputs, Level 3
Investment Valuations And Fair Value Measurements [Line Items]
Beginning Balance	$ 280,352	$ 371,796
Purchases, including payments received in-kind	2,730	9,608
Sales and paydowns of investments	(392)	(208)
Amortization of premium and accretion of discount, net	(29)	223
Net realized losses	(32,894)
Net change in unrealized appreciation/(depreciation)	41,070	(8,636)
Ending Balance	290,837	372,783
Change in net unrealized appreciation/(depreciation) in investments held	21,736	(8,636)
Debt \| Fair Value, Inputs, Level 3
Investment Valuations And Fair Value Measurements [Line Items]
Beginning Balance	172,216	276,377
Purchases, including payments received in-kind	2,730	9,608
Sales and paydowns of investments	(392)	(208)
Amortization of premium and accretion of discount, net	(29)	223
Net realized losses	(32,894)
Net change in unrealized appreciation/(depreciation)	24,402	(1,149)
Ending Balance	166,033	284,851
Change in net unrealized appreciation/(depreciation) in investments held	5,067	(1,149)
Equity \| Fair Value, Inputs, Level 3
Investment Valuations And Fair Value Measurements [Line Items]
Beginning Balance	108,136	95,419
Purchases, including payments received in-kind	0	0
Sales and paydowns of investments	0	0
Amortization of premium and accretion of discount, net	0	0
Net realized losses	0
Net change in unrealized appreciation/(depreciation)	16,668	(7,487)
Ending Balance	124,804	87,932
Change in net unrealized appreciation/(depreciation) in investments held	$ 16,669	$ (7,487)

TCW Direct Lending LLC 10-Q