GUARANTOR AND NON-GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION (Condensed Consolidating Statements of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Condensed consolidating statement of cash flows
Net cash from operating activities	$ 4,596	$ 39,589
Cash flows from investing activities:
Additions to property, plant and equipment	(75,005)	(72,249)
Proceeds from sales of fixed assets	876	921
Acquisitions, net of cash acquired	0	(197)
Costs to obtain or renew permits	(1,075)	(725)
Proceeds from sales of marketable securities	12,870	0
Net cash used in investing activities	(62,334)	(72,250)
Cash flows from financing activities:
Change in uncashed checks	21	26,419
Proceeds from exercise of stock options	0	397
Proceeds from employee stock purchase plan	2,141	1,546
Remittance of shares, net	(750)	(41)
Repurchases of common stock	(1,225)	0
Excess tax benefit of stock-based compensation	117	1,227
Deferred financing costs paid	0	(2,318)
Payments on capital leases	(638)	(1,346)
Issuance costs related to 2012 issuance of common stock	0	(250)
Dividends (paid) / received	0	0
Interest (payments) / received	0	0
Net cash from financing activities	(334)	25,634
Effect of exchange rate change on cash	(2,994)	(705)
Decrease in cash and cash equivalents	(61,066)	(7,732)
Cash and cash equivalents, beginning of period	310,073	229,836
Cash and cash equivalents, end of period	249,007	222,104
Clean Harbors, Inc.
Condensed consolidating statement of cash flows
Net cash from operating activities	(283)	(32,042)
Cash flows from investing activities:
Additions to property, plant and equipment	0	0
Proceeds from sales of fixed assets	0	0
Acquisitions, net of cash acquired		(197)
Costs to obtain or renew permits	0	0
Proceeds from sales of marketable securities	0
Net cash used in investing activities	0	(197)
Cash flows from financing activities:
Change in uncashed checks	0	0
Proceeds from exercise of stock options		397
Proceeds from employee stock purchase plan	2,141	1,546
Remittance of shares, net	(750)	(41)
Repurchases of common stock	(1,225)
Excess tax benefit of stock-based compensation	117	1,227
Deferred financing costs paid		(2,318)
Payments on capital leases	0	0
Issuance costs related to 2012 issuance of common stock		(250)
Dividends (paid) / received	0	0
Interest (payments) / received	0	0
Net cash from financing activities	283	561
Effect of exchange rate change on cash	0	0
Decrease in cash and cash equivalents	0	(31,678)
Cash and cash equivalents, beginning of period	1,006	35,214
Cash and cash equivalents, end of period	1,006	3,536
U.S. Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash from operating activities	2,808	33,154
Cash flows from investing activities:
Additions to property, plant and equipment	(46,287)	(36,962)
Proceeds from sales of fixed assets	228	250
Acquisitions, net of cash acquired		0
Costs to obtain or renew permits	(111)	(113)
Proceeds from sales of marketable securities	0
Net cash used in investing activities	(46,170)	(36,825)
Cash flows from financing activities:
Change in uncashed checks	60	20,562
Proceeds from exercise of stock options		0
Proceeds from employee stock purchase plan	0	0
Remittance of shares, net	0	0
Repurchases of common stock	0
Excess tax benefit of stock-based compensation	0	0
Deferred financing costs paid		0
Payments on capital leases	(41)	(80)
Issuance costs related to 2012 issuance of common stock		0
Dividends (paid) / received	(4,275)	(3,645)
Interest (payments) / received	12,864	11,307
Net cash from financing activities	8,608	28,144
Effect of exchange rate change on cash	0	0
Decrease in cash and cash equivalents	(34,754)	24,473
Cash and cash equivalents, beginning of period	235,445	140,683
Cash and cash equivalents, end of period	200,691	165,156
Foreign Non-Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash from operating activities	2,071	38,477
Cash flows from investing activities:
Additions to property, plant and equipment	(28,718)	(35,287)
Proceeds from sales of fixed assets	648	671
Acquisitions, net of cash acquired		0
Costs to obtain or renew permits	(964)	(612)
Proceeds from sales of marketable securities	12,870
Net cash used in investing activities	(16,164)	(35,228)
Cash flows from financing activities:
Change in uncashed checks	(39)	5,857
Proceeds from exercise of stock options		0
Proceeds from employee stock purchase plan	0	0
Remittance of shares, net	0	0
Repurchases of common stock	0
Excess tax benefit of stock-based compensation	0	0
Deferred financing costs paid		0
Payments on capital leases	(597)	(1,266)
Issuance costs related to 2012 issuance of common stock		0
Dividends (paid) / received	4,275	3,645
Interest (payments) / received	(12,864)	(11,307)
Net cash from financing activities	(9,225)	(3,071)
Effect of exchange rate change on cash	(2,994)	(705)
Decrease in cash and cash equivalents	(26,312)	(527)
Cash and cash equivalents, beginning of period	73,622	53,939
Cash and cash equivalents, end of period	$ 47,310	$ 53,412