GUARANTOR AND NON-GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION (Condensed Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	$ 57,119	$ 39,289
Cash flows from (used in) investing activities:
Additions to property, plant and equipment	(42,462)	(75,781)
Proceeds from sales of fixed assets	1,030	1,273
Acquisitions, net of cash acquired	(11,946)	(34,993)
Proceeds on sale of business	2,018	0
Costs to obtain or renew permits	(751)	(512)
Proceeds from sale of investments	243	0
Intercompany	0	0
Investment in subsidiaries		0
Net cash used in investing activities	(51,868)	(110,013)
Cash flows used in financing activities:
Change in uncashed checks	(7,557)	(5,218)
Proceeds from exercise of stock options	46	0
Issuance of restricted shares, net of shares remitted	(1,021)	(1,425)
Repurchases of common stock	(6,796)	(4,998)
Deferred financing costs paid	(108)	(2,190)
Issuance of senior secured notes, including premium	0	250,625
Intercompany	0	0
Net cash (used in) from financing activities	(15,436)	236,794
Effect of exchange rate change on cash	554	4,567
Increase (decrease) in cash and cash equivalents	(9,631)	170,637
Cash and cash equivalents, beginning of period	306,997	184,708
Cash and cash equivalents, end of period	297,366	355,345
Consolidating Adjustments
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	0	0
Cash flows from (used in) investing activities:
Additions to property, plant and equipment	0	0
Proceeds from sales of fixed assets	0	0
Acquisitions, net of cash acquired	0	0
Proceeds on sale of business	0
Costs to obtain or renew permits	0	0
Proceeds from sale of investments	0
Intercompany	7,771	6,423
Investment in subsidiaries		250,625
Net cash used in investing activities	7,771	257,048
Cash flows used in financing activities:
Change in uncashed checks	0	0
Proceeds from exercise of stock options	0
Issuance of restricted shares, net of shares remitted	0	0
Repurchases of common stock	0	0
Deferred financing costs paid	0	0
Issuance of senior secured notes, including premium		(250,625)
Intercompany	(7,771)	(6,423)
Net cash (used in) from financing activities	(7,771)	(257,048)
Effect of exchange rate change on cash	0	0
Increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of period	0	0
Cash and cash equivalents, end of period	0	0
Clean Harbors, Inc. | Reportable Legal Entities
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	(1,663)	47,201
Cash flows from (used in) investing activities:
Additions to property, plant and equipment	0	0
Proceeds from sales of fixed assets	0	0
Acquisitions, net of cash acquired	0	0
Proceeds on sale of business	1,837
Costs to obtain or renew permits	0	0
Proceeds from sale of investments	243
Intercompany	0	0
Investment in subsidiaries		(250,625)
Net cash used in investing activities	2,080	(250,625)
Cash flows used in financing activities:
Change in uncashed checks	0	0
Proceeds from exercise of stock options	46
Issuance of restricted shares, net of shares remitted	(1,021)	(1,425)
Repurchases of common stock	(6,796)	(4,998)
Deferred financing costs paid	(108)	(2,190)
Issuance of senior secured notes, including premium		250,625
Intercompany	7,771	6,423
Net cash (used in) from financing activities	(108)	248,435
Effect of exchange rate change on cash	0	0
Increase (decrease) in cash and cash equivalents	309	45,011
Cash and cash equivalents, beginning of period	51,417	11,017
Cash and cash equivalents, end of period	51,726	56,028
Guarantor Subsidiaries | Reportable Legal Entities
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	41,144	(3,361)
Cash flows from (used in) investing activities:
Additions to property, plant and equipment	(33,136)	(64,754)
Proceeds from sales of fixed assets	664	277
Acquisitions, net of cash acquired	(11,946)	(34,993)
Proceeds on sale of business	0
Costs to obtain or renew permits	(573)	(465)
Proceeds from sale of investments	0
Intercompany	(7,771)	(6,423)
Investment in subsidiaries		0
Net cash used in investing activities	(52,762)	(106,358)
Cash flows used in financing activities:
Change in uncashed checks	(5,165)	(4,529)
Proceeds from exercise of stock options	0
Issuance of restricted shares, net of shares remitted	0	0
Repurchases of common stock	0	0
Deferred financing costs paid	0	0
Issuance of senior secured notes, including premium		250,625
Intercompany	0	0
Net cash (used in) from financing activities	(5,165)	246,096
Effect of exchange rate change on cash	0	0
Increase (decrease) in cash and cash equivalents	(16,783)	136,377
Cash and cash equivalents, beginning of period	155,943	83,479
Cash and cash equivalents, end of period	139,160	219,856
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	17,638	(4,551)
Cash flows from (used in) investing activities:
Additions to property, plant and equipment	(9,326)	(11,027)
Proceeds from sales of fixed assets	366	996
Acquisitions, net of cash acquired	0	0
Proceeds on sale of business	181
Costs to obtain or renew permits	(178)	(47)
Proceeds from sale of investments	0
Intercompany	0	0
Investment in subsidiaries		0
Net cash used in investing activities	(8,957)	(10,078)
Cash flows used in financing activities:
Change in uncashed checks	(2,392)	(689)
Proceeds from exercise of stock options	0
Issuance of restricted shares, net of shares remitted	0	0
Repurchases of common stock	0	0
Deferred financing costs paid	0	0
Issuance of senior secured notes, including premium		0
Intercompany	0	0
Net cash (used in) from financing activities	(2,392)	(689)
Effect of exchange rate change on cash	554	4,567
Increase (decrease) in cash and cash equivalents	6,843	(10,751)
Cash and cash equivalents, beginning of period	99,637	90,212
Cash and cash equivalents, end of period	$ 106,480	$ 79,461