Document and Entity Information - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Feb. 28, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Entity Registrant Name	Goldman Sachs BDC, Inc.
Entity Central Index Key	0001572694
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	true
Title of 12(b) Security	Common Stock, par value$0.001 per share
Trading Symbol	GSBD
Security Exchange Name	NYSE
Entity File Number	814-00998
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-2176593
Entity Address, Address Line One	200 West Street
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10282
City Area Code	312
Local Phone Number	655-4419
Document Annual Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		109,682,711
Entity Public Float			$ 1,425,180
Documents Incorporated by Reference	Portions of Goldman Sachs BDC, Inc.’s Proxy Statement for its 2024 Annual Meeting of Stockholders are incorporated by reference in this Annual Report on Form 10-K in response to Part III, Items 10, 11, 12, 13 and 14.
Auditor Name	PricewaterhouseCoopers LLP
Auditor Firm ID	238
Auditor Location	Boston, Massachusetts
Document Financial Statement Restatement Recovery Analysis [Flag]	false