GUARANTOR AND NON-GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION (Details 4) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Condensed consolidating statement of cash flows
Net cash from operating activities	$ 175,774	$ 75,629
Cash flows from investing activities:
Additions to property, plant and equipment	(82,971)	(65,460)
Proceeds from slales of fixed assets	3,886	4,891
Acquisitions, net of cash acquired	(43,039)	(205,922)
Costs to obtain or renew permits	(953)	(1,066)
Proceeds from sales of marketable securities	0	388
Payments to Acquire Interest in Subsidiaries and Affiliates		0
Purchase of marketable securities	(10,517)	0
Other	5,120	0
Net cash used in investing activities	(128,474)	(267,169)
Cash flows from financing activities:
Change in uncashed checks	(9,496)	13,746
Proceeds from exercise of stock options	98	783
Proceeds from employee stock purchase plan	3,130	1,556
Remittance of shares, net	(1,216)	(1,807)
Excess tax benefit of stock-based compensation	1,122	1,617
Deferred financing costs paid	(21)	(8,099)
Payments on capital leases	(3,833)	(3,316)
Distribution of cash earned on employee participation plan	(38)	(189)
Issuance of senior secured notes, including premium	0	261,250
Dividends (paid) / received	0	0
Interest (payments) / received	0	0
Proceeds from Intercompany Debt		0
Net cash from financing activities	(10,254)	265,541
Effect of exchange rate change on cash	(1,011)	1,365
(Decrease) increase in cash and cash equivalents	36,035	75,366
Cash and cash equivalents, beginning of period	260,723	302,210
Cash and cash equivalents, end of period	296,758	377,576
Clean Harbors, Inc.
Condensed consolidating statement of cash flows
Net cash from operating activities	(9,706)	4,474
Cash flows from investing activities:
Additions to property, plant and equipment	0	0
Proceeds from slales of fixed assets	0	0
Acquisitions, net of cash acquired	0	0
Costs to obtain or renew permits	0	0
Proceeds from sales of marketable securities		0
Payments to Acquire Interest in Subsidiaries and Affiliates		(173,540)
Purchase of marketable securities	0
Other	0
Net cash used in investing activities	0	(173,540)
Cash flows from financing activities:
Change in uncashed checks	0	0
Proceeds from exercise of stock options	98	783
Proceeds from employee stock purchase plan	3,130	1,556
Remittance of shares, net	(1,216)	(1,807)
Excess tax benefit of stock-based compensation	1,122	1,617
Deferred financing costs paid	(21)	(8,099)
Payments on capital leases	0	0
Distribution of cash earned on employee participation plan	(38)	0
Issuance of senior secured notes, including premium		261,250
Dividends (paid) / received	10,010	10,186
Interest (payments) / received	0	0
Proceeds from Intercompany Debt		0
Net cash from financing activities	13,085	265,486
Effect of exchange rate change on cash	0	0
(Decrease) increase in cash and cash equivalents	3,379	96,420
Cash and cash equivalents, beginning of period	91,581	100,476
Cash and cash equivalents, end of period	94,960	196,896
U.S. Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash from operating activities	48,387	28,763
Cash flows from investing activities:
Additions to property, plant and equipment	(47,808)	(40,991)
Proceeds from slales of fixed assets	3,344	361
Acquisitions, net of cash acquired	(2,276)	0
Costs to obtain or renew permits	(262)	(298)
Proceeds from sales of marketable securities		0
Payments to Acquire Interest in Subsidiaries and Affiliates		115,784
Purchase of marketable securities	0
Other	603
Net cash used in investing activities	(46,399)	74,856
Cash flows from financing activities:
Change in uncashed checks	(4,167)	11,329
Proceeds from exercise of stock options	0	0
Proceeds from employee stock purchase plan	0	0
Remittance of shares, net	0	0
Excess tax benefit of stock-based compensation	0	0
Deferred financing costs paid	0	0
Payments on capital leases	(573)	(318)
Distribution of cash earned on employee participation plan	0	0
Issuance of senior secured notes, including premium		0
Dividends (paid) / received	(23,622)	(24,306)
Interest (payments) / received	36,785	24,132
Proceeds from Intercompany Debt		(120,475)
Net cash from financing activities	8,423	(109,638)
Effect of exchange rate change on cash	0	0
(Decrease) increase in cash and cash equivalents	10,411	(6,019)
Cash and cash equivalents, beginning of period	128,071	124,582
Cash and cash equivalents, end of period	138,482	118,563
Foreign Non-Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash from operating activities	137,093	42,392
Cash flows from investing activities:
Additions to property, plant and equipment	(35,163)	(24,469)
Proceeds from slales of fixed assets	542	4,530
Acquisitions, net of cash acquired	(40,763)	(205,922)
Costs to obtain or renew permits	(691)	(768)
Proceeds from sales of marketable securities		388
Payments to Acquire Interest in Subsidiaries and Affiliates		57,756
Purchase of marketable securities	(10,517)
Other	4,517
Net cash used in investing activities	(82,075)	(168,485)
Cash flows from financing activities:
Change in uncashed checks	(5,329)	2,417
Proceeds from exercise of stock options	0	0
Proceeds from employee stock purchase plan	0	0
Remittance of shares, net	0	0
Excess tax benefit of stock-based compensation	0	0
Deferred financing costs paid	0	0
Payments on capital leases	(3,260)	(2,998)
Distribution of cash earned on employee participation plan	0	(189)
Issuance of senior secured notes, including premium		0
Dividends (paid) / received	13,612	14,120
Interest (payments) / received	(36,785)	(24,132)
Proceeds from Intercompany Debt		120,475
Net cash from financing activities	(31,762)	109,693
Effect of exchange rate change on cash	(1,011)	1,365
(Decrease) increase in cash and cash equivalents	22,245	(15,035)
Cash and cash equivalents, beginning of period	41,071	77,152
Cash and cash equivalents, end of period	$ 63,316	$ 62,117