Commitments and Contingencies - Summary of Unfunded Commitments by Investment Types (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Loss Contingencies [Line Items]
Unfunded commitment balances	$ 162,039	$ 5,139
Adelaide Borrower LLC [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	May 08, 2030
Unfunded commitment balances	$ 5,353
Adelaide Borrower LLC [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	May 08, 2030
Unfunded commitment balances	$ 3,332
Alert SRC Newco LLC [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Dec. 11, 2030
Unfunded commitment balances	$ 7,247
Alert SRC Newco LLC [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Dec. 11, 2030
Unfunded commitment balances	$ 2,174
AMI Buyer Inc [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Oct. 17, 2031
Unfunded commitment balances	$ 4,009
Ascend Partners Services LLC [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Aug. 11, 2031
Unfunded commitment balances	$ 10,401
Ascend Partners Services LLC [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Aug. 11, 2031
Unfunded commitment balances	$ 832
Azurite Intermediate Holdings, Inc. [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Mar. 19, 2031
Unfunded commitment balances	$ 2,076
Baxter Planning Systems, LLC [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	May 20, 2031
Unfunded commitment balances	$ 1,497
Baxter Planning Systems, LLC [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	May 20, 2031
Unfunded commitment balances	$ 1,475
CB Buyer Inc [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Jul. 01, 2031
Unfunded commitment balances	$ 6,037
CB Buyer Inc [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Jul. 01, 2031
Unfunded commitment balances	$ 2,354
CData Software Inc [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Jul. 18, 2030
Unfunded commitment balances	$ 3,083
CData Software Inc [Member] \| First Lien Senior Secured Delayed Draw Term Loan One [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Jul. 18, 2030
Unfunded commitment balances	$ 2,620
CData Software Inc [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Jul. 18, 2030
Unfunded commitment balances	$ 3,699
Coding Solutions Acquisition Inc [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Aug. 07, 2031
Unfunded commitment balances	$ 4,764
Coding Solutions Acquisition Inc [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Aug. 07, 2031
Unfunded commitment balances	$ 372
Cpex Purchaser, LLC [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Mar. 01, 2030
Unfunded commitment balances	$ 1,749
Cpex Purchaser, LLC [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Mar. 01, 2030
Unfunded commitment balances	$ 9,818
FH DMI Buyer Inc [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Oct. 11, 2030
Unfunded commitment balances	$ 6,807
FH DMI Buyer Inc [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Oct. 11, 2030
Unfunded commitment balances	$ 2,042
Guardian Restoration Partners Buyer [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Nov. 03, 2031
Unfunded commitment balances	$ 5,262
Guardian Restoration Partners Buyer [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Nov. 03, 2031
Unfunded commitment balances	$ 1,192
Icefall Parent, Inc. [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Jan. 25, 2030
Unfunded commitment balances	$ 2,375
LogRhythm Inc [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Jul. 02, 2029
Unfunded commitment balances	$ 5,482
Penn TRGRP Holdings LLC [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Sep. 27, 2030
Unfunded commitment balances	$ 1,537	1,258
Penn TRGRP Holdings LLC [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Sep. 27, 2030
Unfunded commitment balances	$ 3,881	$ 3,881
Runway Bidco LLC [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Dec. 17, 2031
Unfunded commitment balances	$ 5,033
Runway Bidco LLC [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Dec. 17, 2031
Unfunded commitment balances	$ 2,517
Sapphire Software Buyer Inc [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Sep. 30, 2031
Unfunded commitment balances	$ 3,656
Thunder Buyer Inc [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Oct. 17, 2030
Unfunded commitment balances	$ 7,319
Thunder Buyer Inc [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Oct. 17, 2030
Unfunded commitment balances	$ 3,904
United Flow Technologies Intermediate HoldCo II, LLC [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Jun. 23, 2031
Unfunded commitment balances	$ 13,902
United Flow Technologies Intermediate HoldCo II, LLC [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Jun. 21, 2030
Unfunded commitment balances	$ 3,083
Xactly Corporation [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Jul. 30, 2027
Unfunded commitment balances	$ 1,575
Zone Company Software Consulting LLC [Member] \| First Lien Senior Secured Delayed Draw Term Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Sep. 13, 2030
Unfunded commitment balances	$ 11,860
Zone Company Software Consulting LLC [Member] \| First Lien Senior Secured Delayed Draw Term Loan One [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Sep. 13, 2030
Unfunded commitment balances	$ 1,366
Zone Company Software Consulting LLC [Member] \| First Lien Senior Secured Revolving Loan [Member]
Loss Contingencies [Line Items]
Commitment expiration date	Sep. 13, 2030
Unfunded commitment balances	$ 6,354

26North BDC, Inc. 10-K