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, 2013	Mar. 31, 2012
Condensed consolidating statement of cash flows
Net cash from operating activities	$ 39,589	$ 29,553
Cash flows from investing activities:
Additions to property, plant and equipment	(72,249)	(27,661)
Proceeds from slales of fixed assets	921	425
Acquisitions, net of cash acquired	(197)	(8,751)
Costs to obtain or renew permits	(725)	(425)
Purchase of marketable securities	0	(4,468)
Other	0	5,120
Net cash used in investing activities	(72,250)	(35,760)
Cash flows from financing activities:
Change in uncashed checks	26,419	(13,576)
Proceeds from exercise of stock options	397	30
Proceeds from employee stock purchase plan	1,546	1,238
Remittance of shares, net	(41)	0
Excess tax benefit of stock-based compensation	1,227	713
Deferred financing costs paid	(2,318)	0
Payments on capital leases	(1,346)	(2,166)
Issuance costs related to 2012 issuance of common stock	(250)	0
Distribution of cash earned on employee participation plan	0	(38)
Dividends (paid) / received	0	0
Interest (payments) / received	0	0
Net cash from financing activities	25,634	(13,799)
Effect of exchange rate change on cash	(705)	810
Decrease in cash and cash equivalents	(7,732)	(19,196)
Cash and cash equivalents, beginning of period	229,836	260,723
Cash and cash equivalents, end of period	222,104	241,527
Clean Harbors, Inc.
Condensed consolidating statement of cash flows
Net cash from operating activities	(32,042)	(18,010)
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	(197)	0
Costs to obtain or renew permits	0	0
Purchase of marketable securities		0
Net cash used in investing activities	(197)	0
Cash flows from financing activities:
Change in uncashed checks	0	0
Proceeds from exercise of stock options	397	30
Proceeds from employee stock purchase plan	1,546	1,238
Remittance of shares, net	(41)
Excess tax benefit of stock-based compensation	1,227	713
Deferred financing costs paid	(2,318)
Payments on capital leases	0	0
Issuance costs related to 2012 issuance of common stock	(250)
Distribution of cash earned on employee participation plan		(38)
Dividends (paid) / received	0	10,010
Interest (payments) / received	0	0
Net cash from financing activities	561	11,953
Effect of exchange rate change on cash	0	0
Decrease in cash and cash equivalents	(31,678)	(6,057)
Cash and cash equivalents, beginning of period	35,214	91,581
Cash and cash equivalents, end of period	3,536	85,524
U.S. Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash from operating activities	33,154	10,827
Cash flows from investing activities:
Additions to property, plant and equipment	(36,962)	(14,678)
Proceeds from slales of fixed assets	250	146
Acquisitions, net of cash acquired	0	(2,276)
Costs to obtain or renew permits	(113)	(106)
Purchase of marketable securities		0
Other		603
Net cash used in investing activities	(36,825)	(16,311)
Cash flows from financing activities:
Change in uncashed checks	20,562	(7,125)
Proceeds from exercise of stock options	0	0
Proceeds from employee stock purchase plan	0	0
Remittance of shares, net	0
Excess tax benefit of stock-based compensation	0	0
Deferred financing costs paid	0
Payments on capital leases	(80)	(361)
Distribution of cash earned on employee participation plan		0
Dividends (paid) / received	(3,645)	(13,428)
Interest (payments) / received	11,307	16,783
Net cash from financing activities	28,144	(4,131)
Effect of exchange rate change on cash	0	0
Decrease in cash and cash equivalents	24,473	(9,615)
Cash and cash equivalents, beginning of period	140,683	128,071
Cash and cash equivalents, end of period	165,156	118,456
Foreign Non-Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash from operating activities	38,477	36,736
Cash flows from investing activities:
Additions to property, plant and equipment	(35,287)	(12,983)
Proceeds from slales of fixed assets	671	279
Acquisitions, net of cash acquired	0	(6,475)
Costs to obtain or renew permits	(612)	(319)
Purchase of marketable securities		(4,468)
Other		4,517
Net cash used in investing activities	(35,228)	(19,449)
Cash flows from financing activities:
Change in uncashed checks	5,857	(6,451)
Proceeds from exercise of stock options	0	0
Proceeds from employee stock purchase plan	0	0
Remittance of shares, net	0
Excess tax benefit of stock-based compensation	0	0
Deferred financing costs paid	0
Payments on capital leases	(1,266)	(1,805)
Distribution of cash earned on employee participation plan		0
Dividends (paid) / received	3,645	3,418
Interest (payments) / received	(11,307)	(16,783)
Net cash from financing activities	(3,071)	(21,621)
Effect of exchange rate change on cash	(705)	810
Decrease in cash and cash equivalents	(527)	(3,524)
Cash and cash equivalents, beginning of period	53,939	41,071
Cash and cash equivalents, end of period	$ 53,412	$ 37,547