GUARANTOR AND NON-GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION (Condensed Consolidating Balance Sheets) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
ASSETS
Cash and cash equivalents	$ 361,658	$ 306,997	$ 257,857	$ 184,708
Intercompany receivables	0	0
Accounts receivables, net	531,696	496,226
Other current assets	266,904	289,648
Property, plant and equipment, net	1,611,971	1,611,827
Investments in subsidiaries	0	0
Intercompany debt receivable	0	0
Goodwill	478,728	465,154
Permits and other intangibles, net	477,639	498,721
Other long-term assets	19,757	13,347
Total assets	3,748,353	3,681,920
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	529,540	504,668
Intercompany payables	0	0
Closure, post-closure and remedial liabilities, net	165,836	166,322
Long-term obligations, less current portion	1,625,971	1,633,272
Intercompany debt payable	0	0
Other long-term liabilities	298,659	293,417
Total liabilities	2,620,006	2,597,679
Stockholders’ equity	1,128,347	1,084,241
Total liabilities and stockholders’ equity	3,748,353	3,681,920
Reportable Legal Entities | Clean Harbors, Inc.
ASSETS
Cash and cash equivalents	51,514	51,417	51,334	11,017
Intercompany receivables	230,084	200,337
Accounts receivables, net	0	0
Other current assets	897	3,096
Property, plant and equipment, net	0	0
Investments in subsidiaries	2,933,843	2,851,571
Intercompany debt receivable	0	0
Goodwill	0	0
Permits and other intangibles, net	0	0
Other long-term assets	2,448	2,446
Total assets	3,218,786	3,108,867
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	22,595	21,805
Intercompany payables	441,873	365,848
Closure, post-closure and remedial liabilities, net	0	0
Long-term obligations, less current portion	1,625,971	1,633,272
Intercompany debt payable	0	3,701
Other long-term liabilities	0	0
Total liabilities	2,090,439	2,024,626
Stockholders’ equity	1,128,347	1,084,241
Total liabilities and stockholders’ equity	3,218,786	3,108,867
Reportable Legal Entities | Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	221,552	155,943	170,183	83,479
Intercompany receivables	451,146	354,836
Accounts receivables, net	435,058	417,029
Other current assets	215,847	234,408
Property, plant and equipment, net	1,182,922	1,211,210
Investments in subsidiaries	585,660	580,124
Intercompany debt receivable	92,938	86,409
Goodwill	415,056	412,638
Permits and other intangibles, net	415,708	435,594
Other long-term assets	13,312	7,582
Total assets	4,029,199	3,895,773
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	385,734	366,831
Intercompany payables	266,776	237,058
Closure, post-closure and remedial liabilities, net	148,791	150,682
Long-term obligations, less current portion	0	0
Intercompany debt payable	21,000	21,000
Other long-term liabilities	278,700	275,649
Total liabilities	1,101,001	1,051,220
Stockholders’ equity	2,928,198	2,844,553
Total liabilities and stockholders’ equity	4,029,199	3,895,773
Reportable Legal Entities | Non-Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	88,592	99,637	36,340	90,212
Intercompany receivables	38,451	49,055
Accounts receivables, net	96,638	79,197
Other current assets	51,871	69,257
Property, plant and equipment, net	429,049	400,617
Investments in subsidiaries	0	0
Intercompany debt receivable	21,000	24,701
Goodwill	63,672	52,516
Permits and other intangibles, net	61,931	63,127
Other long-term assets	5,065	4,387
Total assets	856,269	842,494
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	122,922	133,145
Intercompany payables	11,032	1,322
Closure, post-closure and remedial liabilities, net	17,045	15,640
Long-term obligations, less current portion	0	0
Intercompany debt payable	92,938	86,409
Other long-term liabilities	21,027	18,836
Total liabilities	264,964	255,352
Stockholders’ equity	591,305	587,142
Total liabilities and stockholders’ equity	856,269	842,494
Consolidating Adjustments
ASSETS
Cash and cash equivalents	0	0	$ 0	$ 0
Intercompany receivables	(719,681)	(604,228)
Accounts receivables, net	0	0
Other current assets	(1,711)	(17,113)
Property, plant and equipment, net	0	0
Investments in subsidiaries	(3,519,503)	(3,431,695)
Intercompany debt receivable	(113,938)	(111,110)
Goodwill	0	0
Permits and other intangibles, net	0	0
Other long-term assets	(1,068)	(1,068)
Total assets	(4,355,901)	(4,165,214)
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	(1,711)	(17,113)
Intercompany payables	(719,681)	(604,228)
Closure, post-closure and remedial liabilities, net	0	0
Long-term obligations, less current portion	0	0
Intercompany debt payable	(113,938)	(111,110)
Other long-term liabilities	(1,068)	(1,068)
Total liabilities	(836,398)	(733,519)
Stockholders’ equity	(3,519,503)	(3,431,695)
Total liabilities and stockholders’ equity	$ (4,355,901)	$ (4,165,214)