Document and Entity Information	3 Months Ended
	Mar. 31, 2020 shares
Document and Entity Information
Document Type	10-Q
Document Period End Date	Mar. 31, 2020
Entity Registrant Name	Tri-State Generation & Transmission Association, Inc.
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	0
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001637880
Amendment Flag	false