GUARANTOR AND NON-GUARANTOR SUBSIDIARIES Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed consolidating statement of cash flows
Net cash from operating activities	$ 415,839	$ 324,365	$ 179,531
Cash flows from investing activities:
Additions to property, plant and equipment	(280,207)	(197,397)	(148,513)
Proceeds from sales of fixed assets	4,699	8,125	6,794
Acquisitions, net of cash acquired	(63,264)	(1,373,921)	(336,960)
Additions to intangible assets including costs to obtain or renew permits	(6,740)	(4,046)	(2,927)
Purchase of marketable securities	0	(10,517)	0
Proceeds from sales of marketable securities	0	0	425
Proceeds from sale of long-term investments	0	0	1,000
Other	0	5,120	0
Net cash used in investing activities	(345,512)	(1,572,636)	(480,181)
Cash flows from financing activities:
Change in uncashed checks	12,268	(12,070)	9,822
Proceeds from exercise of stock options	400	288	1,350
Remittance of shares, net	(731)	(2,912)	(4,061)
Excess tax benefit of stock-based compensation	1,409	2,556	3,352
Deferred financing costs paid	(2,504)	(19,056)	(8,463)
Proceeds from employee stock purchase plan	7,425	6,196	3,516
Payments on capital leases	(4,891)	(6,599)	(7,837)
Issuance costs related to issuances of common stock	(250)	0	0
Proceeds from issuance of common stock, net	0	369,520	0
Principal payments on debt	0	(520,000)	0
Distribution of cash earned on employee participation plan	0	(55)	(189)
Issuance of senior unsecured notes, at par	0	1,400,000	0
Issuance of senior secured notes, including premium	0	0	261,250
Net cash from financing activities	13,126	1,217,868	258,740
Effect of exchange rate change on cash	(3,216)	(484)	423
Increase (decrease) in cash and cash equivalents	80,237	(30,887)	(41,487)
Cash and cash equivalents, beginning of year	229,836	260,723	302,210
Cash and cash equivalents, end of year	310,073	229,836	260,723
Clean Harbors, Inc.
Condensed consolidating statement of cash flows
Net cash from operating activities	(33,932)	(45,655)	(17,428)
Cash flows from investing activities:
Additions to property, plant and equipment	0	0	0
Proceeds from sales of fixed assets	0	0	0
Acquisitions, net of cash acquired	(6,025)	(1,257,259)	0
Additions to intangible assets including costs to obtain or renew permits	0	0	0
Purchase of marketable securities		0
Proceeds from sales of marketable securities			0
Proceeds from sale of long-term investments			0
Other		0
Investment in subsidiaries			(258,597)
Net cash used in investing activities	(6,025)	(1,257,259)	(258,597)
Cash flows from financing activities:
Change in uncashed checks	0	0	0
Proceeds from exercise of stock options	400	288	1,350
Remittance of shares, net	(731)	(2,912)	(4,061)
Excess tax benefit of stock-based compensation	1,409	2,556	3,352
Deferred financing costs paid	(2,504)	(19,056)	(8,463)
Proceeds from employee stock purchase plan	7,425	6,196	3,516
Payments on capital leases	0	0	0
Issuance costs related to issuances of common stock	(250)
Proceeds from issuance of common stock, net		369,520
Principal payments on debt		(520,000)
Distribution of cash earned on employee participation plan		(55)	0
Issuance of senior unsecured notes, at par		1,400,000
Issuance of senior secured notes, including premium			261,250
Interest (payments) / received	0	10,010	10,186
Interest (payments) / received	0	0	0
Intercompany debt			0
Net cash from financing activities	5,749	1,246,547	267,130
Effect of exchange rate change on cash	0	0	0
Increase (decrease) in cash and cash equivalents	(34,208)	(56,367)	(8,895)
Cash and cash equivalents, beginning of year	35,214	91,581	100,476
Cash and cash equivalents, end of year	1,006	35,214	91,581
U.S. Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash from operating activities	264,491	179,425	90,015
Cash flows from investing activities:
Additions to property, plant and equipment	(145,395)	(117,344)	(92,531)
Proceeds from sales of fixed assets	1,078	3,810	657
Acquisitions, net of cash acquired	(57,239)	(63,351)	(50,166)
Additions to intangible assets including costs to obtain or renew permits	(5,247)	(712)	(465)
Purchase of marketable securities		0
Proceeds from sales of marketable securities			0
Proceeds from sale of long-term investments			1,000
Other		500
Investment in subsidiaries			178,884
Net cash used in investing activities	(206,803)	(177,097)	37,379
Cash flows from financing activities:
Change in uncashed checks	9,922	(6,761)	6,558
Proceeds from exercise of stock options	0	0	0
Remittance of shares, net	0	0	0
Excess tax benefit of stock-based compensation	0	0	0
Deferred financing costs paid	0	0	0
Proceeds from employee stock purchase plan	0	0	0
Payments on capital leases	(227)	(850)	(820)
Issuance costs related to issuances of common stock	0
Proceeds from issuance of common stock, net		0
Principal payments on debt		0
Distribution of cash earned on employee participation plan		0	0
Issuance of senior unsecured notes, at par		0
Issuance of senior secured notes, including premium			0
Interest (payments) / received	(13,545)	(23,815)	(24,306)
Interest (payments) / received	40,924	41,710	35,088
Intercompany debt			(140,425)
Net cash from financing activities	37,074	10,284	(123,905)
Effect of exchange rate change on cash	0	0	0
Increase (decrease) in cash and cash equivalents	94,762	12,612	3,489
Cash and cash equivalents, beginning of year	140,683	128,071	124,582
Cash and cash equivalents, end of year	235,445	140,683	128,071
Foreign Non-Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash from operating activities	185,280	190,595	106,944
Cash flows from investing activities:
Additions to property, plant and equipment	(134,812)	(80,053)	(55,982)
Proceeds from sales of fixed assets	3,621	4,315	6,137
Acquisitions, net of cash acquired	0	(53,311)	(286,794)
Additions to intangible assets including costs to obtain or renew permits	(1,493)	(3,334)	(2,462)
Purchase of marketable securities		(10,517)
Proceeds from sales of marketable securities			425
Proceeds from sale of long-term investments			0
Other		4,620
Investment in subsidiaries			79,713
Net cash used in investing activities	(132,684)	(138,280)	(258,963)
Cash flows from financing activities:
Change in uncashed checks	2,346	(5,309)	3,264
Proceeds from exercise of stock options	0	0	0
Remittance of shares, net	0	0	0
Excess tax benefit of stock-based compensation	0	0	0
Deferred financing costs paid	0	0	0
Proceeds from employee stock purchase plan	0	0	0
Payments on capital leases	(4,664)	(5,749)	(7,017)
Issuance costs related to issuances of common stock	0
Proceeds from issuance of common stock, net		0
Principal payments on debt		0
Distribution of cash earned on employee participation plan		0	(189)
Issuance of senior unsecured notes, at par		0
Issuance of senior secured notes, including premium			0
Interest (payments) / received	13,545	13,805	14,120
Interest (payments) / received	(40,924)	(41,710)	(35,088)
Intercompany debt			140,425
Net cash from financing activities	(29,697)	(38,963)	115,515
Effect of exchange rate change on cash	(3,216)	(484)	423
Increase (decrease) in cash and cash equivalents	19,683	12,868	(36,081)
Cash and cash equivalents, beginning of year	53,939	41,071	77,152
Cash and cash equivalents, end of year	73,622	53,939	41,071
Parent
Condensed consolidating statement of cash flows
Net cash from operating activities	415,839	324,365	179,531
Cash flows from investing activities:
Additions to property, plant and equipment	(280,207)	(197,397)	(148,513)
Proceeds from sales of fixed assets	4,699	8,125	6,794
Acquisitions, net of cash acquired	(63,264)	(1,373,921)	(336,960)
Additions to intangible assets including costs to obtain or renew permits	(6,740)	(4,046)	(2,927)
Purchase of marketable securities		(10,517)
Proceeds from sales of marketable securities			425
Proceeds from sale of long-term investments			1,000
Other		5,120
Investment in subsidiaries			0
Net cash used in investing activities	(345,512)	(1,572,636)	(480,181)
Cash flows from financing activities:
Change in uncashed checks	12,268	(12,070)	9,822
Proceeds from exercise of stock options	400	288	1,350
Remittance of shares, net	(731)	(2,912)	(4,061)
Excess tax benefit of stock-based compensation	1,409	2,556	3,352
Deferred financing costs paid	(2,504)	(19,056)	(8,463)
Proceeds from employee stock purchase plan	7,425	6,196	3,516
Payments on capital leases	(4,891)	(6,599)	(7,837)
Issuance costs related to issuances of common stock	(250)
Proceeds from issuance of common stock, net		369,520
Principal payments on debt		(520,000)
Distribution of cash earned on employee participation plan		(55)	(189)
Issuance of senior unsecured notes, at par		1,400,000
Issuance of senior secured notes, including premium			261,250
Interest (payments) / received	0	0	0
Interest (payments) / received	0	0	0
Intercompany debt			0
Net cash from financing activities	13,126	1,217,868	258,740
Effect of exchange rate change on cash	(3,216)	(484)	423
Increase (decrease) in cash and cash equivalents	80,237	(30,887)	(41,487)
Cash and cash equivalents, beginning of year	229,836	260,723	302,210
Cash and cash equivalents, end of year	$ 310,073	$ 229,836	$ 260,723