v3.25.2
Cover
Aug. 28, 2025
Cover [Abstract]  
Document Type 8-K
Document Period End Date Aug. 28, 2025
Entity Registrant Name TRI-STATE GENERATION AND TRANSMISSION ASSOCIATION, INC.
Entity Incorporation, State or Country Code CO
Entity File Number 333-212006
Entity Tax Identification Number 84-0464189
Entity Address, Address Line One 1100 W. 116th Avenue
Entity Address, City or Town Westminster
Entity Address, State or Province CO
Entity Address, Postal Zip Code 80234
City Area Code 303
Local Phone Number 452-6111
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Emerging Growth Company false
Amendment Flag false
Entity Central Index Key 0001637880