GUARANTOR AND NON-GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION (Details 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010
ASSETS
Cash and cash equivalents	$ 241,527	$ 260,723	$ 531,763	$ 302,210
Intercompany receivables	0	0
Other current assets	640,358	631,145
Property, plant and equipment, net	918,684	903,947
Investments in subsidiaries	0	0
Intercompany debt receivable	0	0
Other long-term assets	292,326	289,988
Total assets	2,092,895	2,085,803
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	342,227	381,742
Intercompany payables	0	0
Closure, post-closure and remedial liabilities, net	150,445	155,142
Long-term obligations	523,833	524,203
Capital lease obligations, net	5,406	6,375
Intercompany debt payable	0	0
Other long-term liabilities	119,706	117,354
Total liabilities	1,141,617	1,184,816
Stockholders' equity	951,278	900,987
Total liabilities and stockholders' equity	2,092,895	2,085,803
Clean Harbors, Inc.
ASSETS
Cash and cash equivalents	85,524	91,581	369,241	100,476
Intercompany receivables	321,849	319,444
Other current assets	36,339	43,687
Property, plant and equipment, net	0	0
Investments in subsidiaries	1,117,420	1,064,966
Intercompany debt receivable	0	0
Other long-term assets	12,766	13,228
Total assets	1,573,898	1,532,906
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	6,014	15,612
Intercompany payables	0	0
Closure, post-closure and remedial liabilities, net	0	0
Long-term obligations	523,833	524,203
Capital lease obligations, net	0	0
Intercompany debt payable	3,701	3,701
Other long-term liabilities	89,072	88,403
Total liabilities	622,620	631,919
Stockholders' equity	951,278	900,987
Total liabilities and stockholders' equity	1,573,898	1,532,906
U.S. Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	118,456	128,071	111,038	124,582
Intercompany receivables	0	0
Other current assets	313,765	324,607
Property, plant and equipment, net	400,336	392,566
Investments in subsidiaries	453,810	421,648
Intercompany debt receivable	481,838	472,929
Other long-term assets	111,200	111,104
Total assets	1,879,405	1,850,925
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	206,381	220,968
Intercompany payables	425,899	446,267
Closure, post-closure and remedial liabilities, net	128,953	133,773
Long-term obligations	0	0
Capital lease obligations, net	416	475
Intercompany debt payable	0	0
Other long-term liabilities	7,592	7,588
Total liabilities	769,241	809,071
Stockholders' equity	1,110,164	1,041,854
Total liabilities and stockholders' equity	1,879,405	1,850,925
Foreign Non-Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	37,547	41,071	51,484	77,152
Intercompany receivables	104,050	126,823
Other current assets	290,254	262,851
Property, plant and equipment, net	518,348	511,381
Investments in subsidiaries	91,754	91,654
Intercompany debt receivable	3,701	3,701
Other long-term assets	168,360	165,656
Total assets	1,214,014	1,203,137
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	129,832	145,162
Intercompany payables	0	0
Closure, post-closure and remedial liabilities, net	21,492	21,369
Long-term obligations	0	0
Capital lease obligations, net	4,990	5,900
Intercompany debt payable	481,838	472,929
Other long-term liabilities	23,042	21,363
Total liabilities	661,194	666,723
Stockholders' equity	552,820	536,414
Total liabilities and stockholders' equity	1,214,014	1,203,137
Consolidating Adjustments
ASSETS
Cash and cash equivalents	0	0
Intercompany receivables	(425,899)	(446,267)
Other current assets	0	0
Property, plant and equipment, net	0	0
Investments in subsidiaries	(1,662,984)	(1,578,268)
Intercompany debt receivable	(485,539)	(476,630)
Other long-term assets	0	0
Total assets	(2,574,422)	(2,501,165)
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	0	0
Intercompany payables	(425,899)	(446,267)
Closure, post-closure and remedial liabilities, net	0	0
Long-term obligations	0	0
Capital lease obligations, net	0	0
Intercompany debt payable	(485,539)	(476,630)
Other long-term liabilities	0	0
Total liabilities	(911,438)	(922,897)
Stockholders' equity	(1,662,984)	(1,578,268)
Total liabilities and stockholders' equity	$ (2,574,422)	$ (2,501,165)