GUARANTOR AND NON-GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION (Condensed Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	$ 39,289	$ 84,777
Cash flows from (used in) investing activities:
Additions to property, plant and equipment	(75,781)	(52,949)
Proceeds from sales of fixed assets	1,273	760
Acquisitions, net of cash acquired	(34,993)	0
Costs to obtain or renew permits	(512)	(1,171)
Investment in subsidiaries	0
Intercompany	0	0
Net cash used in investing activities	(110,013)	(53,360)
Cash flows from (used in) financing activities:
Change in uncashed checks	(5,218)	(20,268)
Issuance of restricted shares, net of shares remitted	(1,425)	(1,154)
Repurchases of common stock	(4,998)	(15,379)
Deferred financing costs paid	(2,190)	0
Excess tax benefit of stock-based compensation	0	5
Payments of capital leases	0	(398)
Issuance of senior secured notes, including premium	250,625
Intercompany	0	0
Net cash from financing activities	236,794	(37,194)
Effect of exchange rate change on cash	4,567	(7,363)
Increase (decrease) in cash and cash equivalents	170,637	(13,140)
Cash and cash equivalents, beginning of period	184,708	246,879
Cash and cash equivalents, end of period	355,345	233,739
Consolidating Adjustments
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities		0
Cash flows from (used in) investing activities:
Investment in subsidiaries	250,625
Intercompany	6,423	108,435
Net cash used in investing activities	257,048	108,435
Cash flows from (used in) financing activities:
Issuance of senior secured notes, including premium	(250,625)
Intercompany	(6,423)	(108,435)
Net cash from financing activities	(257,048)	(108,435)
Clean Harbors, Inc.
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	47,201	(8,032)
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
Costs to obtain or renew permits	0	0
Investment in subsidiaries	(250,625)
Intercompany	0	0
Net cash used in investing activities	(250,625)	0
Cash flows from (used in) financing activities:
Change in uncashed checks	0	0
Issuance of restricted shares, net of shares remitted	(1,425)	(1,154)
Repurchases of common stock	(4,998)	(15,379)
Deferred financing costs paid	(2,190)
Excess tax benefit of stock-based compensation		5
Payments of capital leases		0
Issuance of senior secured notes, including premium	250,625
Intercompany	6,423	108,435
Net cash from financing activities	248,435	91,907
Effect of exchange rate change on cash	0	0
Increase (decrease) in cash and cash equivalents	45,011	83,875
Cash and cash equivalents, beginning of period	11,017	1,006
Cash and cash equivalents, end of period	56,028	84,881
U.S. Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	(3,361)	85,311
Cash flows from (used in) investing activities:
Additions to property, plant and equipment	(64,754)	(37,670)
Proceeds from sales of fixed assets	277	113
Acquisitions, net of cash acquired	(34,993)
Costs to obtain or renew permits	(465)	0
Investment in subsidiaries	0
Intercompany	(6,423)	(108,435)
Net cash used in investing activities	(106,358)	(145,992)
Cash flows from (used in) financing activities:
Change in uncashed checks	(4,529)	(14,694)
Issuance of restricted shares, net of shares remitted	0	0
Repurchases of common stock	0	0
Deferred financing costs paid	0
Excess tax benefit of stock-based compensation		0
Payments of capital leases		(164)
Issuance of senior secured notes, including premium	250,625
Intercompany	0	0
Net cash from financing activities	246,096	(14,858)
Effect of exchange rate change on cash	0	0
Increase (decrease) in cash and cash equivalents	136,377	(75,539)
Cash and cash equivalents, beginning of period	83,479	154,147
Cash and cash equivalents, end of period	219,856	78,608
Foreign Non-Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	(4,551)	7,498
Cash flows from (used in) investing activities:
Additions to property, plant and equipment	(11,027)	(15,279)
Proceeds from sales of fixed assets	996	647
Acquisitions, net of cash acquired	0
Costs to obtain or renew permits	(47)	(1,171)
Investment in subsidiaries	0
Intercompany	0	0
Net cash used in investing activities	(10,078)	(15,803)
Cash flows from (used in) financing activities:
Change in uncashed checks	(689)	(5,574)
Issuance of restricted shares, net of shares remitted	0	0
Repurchases of common stock	0	0
Deferred financing costs paid	0
Excess tax benefit of stock-based compensation		0
Payments of capital leases		(234)
Issuance of senior secured notes, including premium	0
Intercompany	0	0
Net cash from financing activities	(689)	(5,808)
Effect of exchange rate change on cash	4,567	(7,363)
Increase (decrease) in cash and cash equivalents	(10,751)	(21,476)
Cash and cash equivalents, beginning of period	90,212	91,726
Cash and cash equivalents, end of period	$ 79,461	$ 70,250