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, 2015	Mar. 31, 2014
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	$ 84,777	$ 4,596
Cash flows from investing activities:
Additions to property, plant and equipment	(52,949)	(75,005)
Proceeds from sales of fixed assets	760	876
Costs to obtain or renew permits	(1,171)	(1,075)
Proceeds from sale of long term investments		12,870
Intercompany	0
Net cash used in investing activities	(53,360)	(62,334)
Cash flows from financing activities:
Change in uncashed checks	(20,268)	21
Proceeds from employee stock purchase plan	0	2,141
Issuance of restricted shares, net of shares remitted	(1,154)	(750)
Repurchases of common stock	(15,379)	(1,225)
Excess tax benefit of stock-based compensation	5	117
Payments on capital leases	(398)	(638)
Dividends (paid) / received		0
Intercompany	0	0
Net cash from financing activities	(37,194)	(334)
Effect of exchange rate change on cash	(7,363)	(2,994)
Decrease in cash and cash equivalents	(13,140)	(61,066)
Cash and cash equivalents, beginning of period	246,879	310,073
Cash and cash equivalents, end of period	233,739	249,007
Clean Harbors, Inc.
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	(8,032)	(49,377)
Cash flows from investing activities:
Additions to property, plant and equipment	0	0
Proceeds from sales of fixed assets	0	0
Costs to obtain or renew permits	0	0
Proceeds from sale of long term investments		0
Intercompany	0	0
Net cash used in investing activities	0	0
Cash flows from financing activities:
Change in uncashed checks	0	0
Proceeds from employee stock purchase plan		2,141
Issuance of restricted shares, net of shares remitted	(1,154)	(750)
Repurchases of common stock	(15,379)	(1,225)
Excess tax benefit of stock-based compensation	5	117
Payments on capital leases	0	0
Dividends (paid) / received		0
Intercompany	108,435	49,094
Net cash from financing activities	91,907	49,377
Effect of exchange rate change on cash	0	0
Decrease in cash and cash equivalents	83,875	0
Cash and cash equivalents, beginning of period	1,006	1,006
Cash and cash equivalents, end of period	84,881	1,006
U.S. Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	85,311	72,813
Cash flows from investing activities:
Additions to property, plant and equipment	(37,670)	(46,287)
Proceeds from sales of fixed assets	113	228
Costs to obtain or renew permits	0	(111)
Proceeds from sale of long term investments		0
Intercompany	(108,435)	(49,094)
Net cash used in investing activities	(145,992)	(95,264)
Cash flows from financing activities:
Change in uncashed checks	(14,694)	60
Proceeds from employee stock purchase plan		0
Issuance of restricted shares, net of shares remitted	0	0
Repurchases of common stock	0	0
Excess tax benefit of stock-based compensation	0	0
Payments on capital leases	(164)	(42)
Dividends (paid) / received		(12,321)
Intercompany	0	0
Net cash from financing activities	(14,858)	(12,303)
Effect of exchange rate change on cash	0	0
Decrease in cash and cash equivalents	(75,539)	(34,754)
Cash and cash equivalents, beginning of period	154,147	235,505
Cash and cash equivalents, end of period	78,608	200,751
Foreign Non-Guarantor Subsidiaries
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities	7,498	(6,519)
Cash flows from investing activities:
Additions to property, plant and equipment	(15,279)	(28,718)
Proceeds from sales of fixed assets	647	648
Costs to obtain or renew permits	(1,171)	(964)
Proceeds from sale of long term investments		12,870
Intercompany	0	0
Net cash used in investing activities	(15,803)	(16,164)
Cash flows from financing activities:
Change in uncashed checks	(5,574)	(39)
Proceeds from employee stock purchase plan		0
Issuance of restricted shares, net of shares remitted	0	0
Repurchases of common stock	0	0
Excess tax benefit of stock-based compensation	0	0
Payments on capital leases	(234)	(596)
Dividends (paid) / received		0
Intercompany	0	0
Net cash from financing activities	(5,808)	(635)
Effect of exchange rate change on cash	(7,363)	(2,994)
Decrease in cash and cash equivalents	(21,476)	(26,312)
Cash and cash equivalents, beginning of period	91,726	73,562
Cash and cash equivalents, end of period	70,250	47,250
Consolidating Adjustments
Condensed consolidating statement of cash flows
Net cash (used in) from operating activities		(12,321)
Cash flows from investing activities:
Intercompany	(108,435)	49,094
Net cash used in investing activities	108,435	49,094
Cash flows from financing activities:
Dividends (paid) / received		12,321
Intercompany	(108,435)	(49,094)
Net cash from financing activities	$ (108,435)	$ (36,773)