v3.25.2
Cover
Jun. 30, 2025
Document Information [Line Items]  
Document Type 8-K
Amendment Flag false
Document Period End Date Jun. 30, 2025
Entity Registrant Name BAIN CAPITAL SPECIALTY FINANCE, INC.
Entity Central Index Key 0001655050
Entity Emerging Growth Company false
Securities Act File Number 814-01175
Entity Incorporation, State or Country Code DE
Entity Tax Identification Number 81-2878769
Entity Address, Address Line One 200 Clarendon Street
Entity Address, Address Line Two 37th Floor
Entity Address, City or Town Boston
Entity Address, State or Province MA
Entity Address, Postal Zip Code 02116
City Area Code 617
Local Phone Number 516-2000
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Common Stock, par value $0.001 per share
Trading Symbol BCSF
Security Exchange Name NYSE