v3.25.4

Cover Page - USD ($) $ in Billions	12 Months Ended
Cover Page - USD ($) $ in Billions	Dec. 31, 2025	Jan. 31, 2026	Jun. 30, 2025
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2025
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	000-23211
Entity Registrant Name	CASELLA WASTE SYSTEMS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	03-0338873
Entity Address, Address Line One	25 Greens Hill Lane
Entity Address, City or Town	Rutland
Entity Address, State or Province	VT
Entity Address, Postal Zip Code	05701
City Area Code	(802
Local Phone Number	775-0325
Title of 12(b) Security	Class A common stock, $0.01 par value per share
Trading Symbol	CWST
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	true
Document Financial Statement Restatement Recovery Analysis [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 7.2
Documents Incorporated by Reference	Part III of this Annual Report on Form 10-K incorporates by reference information from the definitive Proxy Statement for the registrant’s 2026 Annual Meeting of Stockholders or a Form10-K/A to be filed with the Securities and Exchange Commission not later than 120 days after the registrant’s fiscal year ended December 31, 2025
Entity Central Index Key	0000911177
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Amendment Flag	false
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		62,526,567
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		988,200

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CASELLA WASTE SYSTEMS INC 10-K