GUARANTOR AND NON-GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
ASSETS
Cash and cash equivalents	$ 260,723	$ 302,210	$ 233,546	$ 249,524
Intercompany receivables	0	0
Other current assets	631,145	450,327
Property, plant and equipment, net	903,947	655,394
Investments in subsidiaries	0	0
Intercompany debt receivable	0	0
Other long-term assets	289,988	194,544
Total assets	2,085,803	1,602,475
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	381,742	306,284
Intercompany payables	0	0
Closure, post-closure and remedial liabilities, net	155,142	161,774
Long-term obligations	524,203	264,007
Capital lease obligations, net	6,375	6,839
Intercompany debt payable	0	0
Other long-term liabilities	117,354	82,744
Total liabilities	1,184,816	821,648
Stockholders' equity	900,987	780,827	613,825	429,045
Total liabilities and stockholders' equity	2,085,803	1,602,475
Clean Harbors, Inc.
ASSETS
Cash and cash equivalents	91,581	100,476	141,338	121,894
Intercompany receivables	319,444	371,559
Other current assets	43,687	15,521
Property, plant and equipment, net	0	0
Investments in subsidiaries	1,064,966	628,723
Intercompany debt receivable	0	0
Other long-term assets	13,228	7,768
Total assets	1,532,906	1,124,047
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	15,612	13,935
Intercompany payables	0	0
Closure, post-closure and remedial liabilities, net	0	0
Long-term obligations	524,203	264,007
Capital lease obligations, net	0	0
Intercompany debt payable	3,701	3,701
Other long-term liabilities	88,403	61,577
Total liabilities	631,919	343,220
Stockholders' equity	900,987	780,827
Total liabilities and stockholders' equity	1,532,906	1,124,047
U.S. Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	128,071	124,582	50,408	67,934
Intercompany receivables	0	0
Other current assets	324,607	279,895
Property, plant and equipment, net	392,566	302,028
Investments in subsidiaries	421,648	259,294
Intercompany debt receivable	472,929	368,804
Other long-term assets	111,104	87,888
Total assets	1,850,925	1,422,491
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	220,968	201,384
Intercompany payables	446,267	222,750
Closure, post-closure and remedial liabilities, net	133,773	141,280
Long-term obligations	0	0
Capital lease obligations, net	475	249
Intercompany debt payable	0	0
Other long-term liabilities	7,588	2,531
Total liabilities	809,071	568,194
Stockholders' equity	1,041,854	854,297
Total liabilities and stockholders' equity	1,850,925	1,422,491
Foreign Non-Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	41,071	77,152	41,800	59,696
Intercompany receivables	126,823	0
Other current assets	262,851	154,911
Property, plant and equipment, net	511,381	353,366
Investments in subsidiaries	91,654	91,654
Intercompany debt receivable	3,701	3,701
Other long-term assets	165,656	98,888
Total assets	1,203,137	779,672
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	145,162	90,965
Intercompany payables	0	148,809
Closure, post-closure and remedial liabilities, net	21,369	20,494
Long-term obligations	0	0
Capital lease obligations, net	5,900	6,590
Intercompany debt payable	472,929	368,804
Other long-term liabilities	21,363	18,636
Total liabilities	666,723	654,298
Stockholders' equity	536,414	125,374
Total liabilities and stockholders' equity	1,203,137	779,672
Consolidating Adjustments
ASSETS
Cash and cash equivalents	0	0
Intercompany receivables	(446,267)	(371,559)
Other current assets	0	0
Property, plant and equipment, net	0	0
Investments in subsidiaries	(1,578,268)	(979,671)
Intercompany debt receivable	(476,630)	(372,505)
Other long-term assets	0	0
Total assets	(2,501,165)	(1,723,735)
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	0	0
Intercompany payables	(446,267)	(371,559)
Closure, post-closure and remedial liabilities, net	0	0
Long-term obligations	0	0
Capital lease obligations, net	0	0
Intercompany debt payable	(476,630)	(372,505)
Other long-term liabilities	0	0
Total liabilities	(922,897)	(744,064)
Stockholders' equity	(1,578,268)	(979,671)
Total liabilities and stockholders' equity	$ (2,501,165)	$ (1,723,735)