Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 31, 2016
Document Information [Line Items]
Entity Registrant Name	CASELLA WASTE SYSTEMS INC
Entity Central Index Key	0000911177
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q3
Amendment Flag	false
Trading Symbol	CWST
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		40,500,202
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		988,200