GUARANTOR AND NON-GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION (Consolidating Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Total revenues	$ 849,140	$ 752,788	$ 1,598,918	$ 1,441,729
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	583,584	519,803	1,130,009	1,016,388
Selling, general and administrative expenses	125,995	112,294	241,083	224,515
Accretion of environmental liabilities	2,448	2,416	4,878	4,706
Depreciation and amortization	72,760	71,531	147,604	143,943
Income from operations	64,353	46,744	75,344	52,177
Other income (expense), net	846	(833)	547	(2,382)
Loss on early extinguishment of debt	0	(6,045)	0	(6,045)
Gain on sale of business	0	31,722	0	31,722
Interest (expense) income, net	(20,769)	(22,492)	(41,039)	(45,068)
Equity in earnings of subsidiaries, net of taxes	0	0	0	0
Intercompany interest income (expense)	0	0	0	0
Income before (benefit) provision for income taxes	44,430	49,096	34,852	30,404
(Benefit) provision for income taxes	13,683	23,216	16,736	25,917
Net income	30,747	25,880	18,116	4,487
Other comprehensive loss	(4,942)	15,098	(21,688)	21,149
Comprehensive income (loss)	25,805	40,978	(3,572)	25,636
Reportable Legal Entities | Clean Harbors, Inc.
Revenues:
Total revenues	0	0	0	0
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	0	0	0	0
Selling, general and administrative expenses	133	27	168	51
Accretion of environmental liabilities	0	0	0	0
Depreciation and amortization	0	0	0	0
Income from operations	(133)	(27)	(168)	(51)
Other income (expense), net	0	(76)	0	(222)
Loss on early extinguishment of debt		(6,045)		(6,045)
Gain on sale of business		0		0
Interest (expense) income, net	(21,216)	(22,614)	(42,215)	(45,273)
Equity in earnings of subsidiaries, net of taxes	46,118	43,167	48,632	35,530
Intercompany interest income (expense)	0	0	0	0
Income before (benefit) provision for income taxes	24,769	14,405	6,249	(16,061)
(Benefit) provision for income taxes	(5,978)	(11,475)	(11,867)	(20,548)
Net income	30,747	25,880	18,116	4,487
Other comprehensive loss	(4,942)	15,098	(21,688)	21,149
Comprehensive income (loss)	25,805	40,978	(3,572)	25,636
Reportable Legal Entities | Guarantor Subsidiaries
Revenues:
Total revenues	682,412	600,660	1,285,477	1,160,615
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	464,086	405,605	887,304	796,255
Selling, general and administrative expenses	105,022	92,504	198,865	184,675
Accretion of environmental liabilities	2,194	2,181	4,370	4,236
Depreciation and amortization	52,864	51,937	106,568	103,837
Income from operations	58,246	48,433	88,370	71,612
Other income (expense), net	269	(406)	184	(1,795)
Loss on early extinguishment of debt		0		0
Gain on sale of business		31,722		31,722
Interest (expense) income, net	238	240	743	359
Equity in earnings of subsidiaries, net of taxes	2,230	(5,332)	(17,832)	(27,156)
Intercompany interest income (expense)	1,084	1,268	2,445	2,565
Income before (benefit) provision for income taxes	62,067	75,925	73,910	77,307
(Benefit) provision for income taxes	18,228	31,981	27,329	41,618
Net income	43,839	43,944	46,581	35,689
Other comprehensive loss	(4,942)	15,098	(21,688)	21,149
Comprehensive income (loss)	38,897	59,042	24,893	56,838
Reportable Legal Entities | Non-Guarantor Subsidiaries
Revenues:
Total revenues	182,798	166,654	346,649	313,056
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	135,568	128,724	275,913	252,075
Selling, general and administrative expenses	20,840	19,763	42,050	39,789
Accretion of environmental liabilities	254	235	508	470
Depreciation and amortization	19,896	19,594	41,036	40,106
Income from operations	6,240	(1,662)	(12,858)	(19,384)
Other income (expense), net	577	(351)	363	(365)
Loss on early extinguishment of debt		0		0
Gain on sale of business		0		0
Interest (expense) income, net	209	(118)	433	(154)
Equity in earnings of subsidiaries, net of taxes	0	0	0	0
Intercompany interest income (expense)	(1,084)	(1,268)	(2,445)	(2,565)
Income before (benefit) provision for income taxes	5,942	(3,399)	(14,507)	(22,468)
(Benefit) provision for income taxes	1,433	2,710	1,274	4,847
Net income	4,509	(6,109)	(15,781)	(27,315)
Other comprehensive loss	(10,435)	12,837	(24,442)	17,869
Comprehensive income (loss)	(5,926)	6,728	(40,223)	(9,446)
Consolidating Adjustments
Revenues:
Total revenues	(16,070)	(14,526)	(33,208)	(31,942)
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	(16,070)	(14,526)	(33,208)	(31,942)
Selling, general and administrative expenses	0	0	0	0
Accretion of environmental liabilities	0	0	0	0
Depreciation and amortization	0	0	0	0
Income from operations	0	0	0	0
Other income (expense), net	0	0	0	0
Loss on early extinguishment of debt		0		0
Gain on sale of business		0		0
Interest (expense) income, net	0	0	0	0
Equity in earnings of subsidiaries, net of taxes	(48,348)	(37,835)	(30,800)	(8,374)
Intercompany interest income (expense)	0	0	0	0
Income before (benefit) provision for income taxes	(48,348)	(37,835)	(30,800)	(8,374)
(Benefit) provision for income taxes	0	0	0	0
Net income	(48,348)	(37,835)	(30,800)	(8,374)
Other comprehensive loss	15,377	(27,935)	46,130	(39,018)
Comprehensive income (loss)	(32,971)	(65,770)	15,330	(47,392)
Service
Revenues:
Total revenues	696,779	610,940	1,316,498	1,171,154
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	473,423	412,356	921,072	803,443
Service | Reportable Legal Entities | Clean Harbors, Inc.
Revenues:
Total revenues	0	0	0	0
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	0	0	0	0
Service | Reportable Legal Entities | Guarantor Subsidiaries
Revenues:
Total revenues	544,521	474,801	1,026,004	918,106
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	361,644	306,960	689,824	601,105
Service | Reportable Legal Entities | Non-Guarantor Subsidiaries
Revenues:
Total revenues	165,435	147,924	317,836	278,995
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	124,956	117,181	258,590	228,285
Service | Consolidating Adjustments
Revenues:
Total revenues	(13,177)	(11,785)	(27,342)	(25,947)
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	(13,177)	(11,785)	(27,342)	(25,947)
Product
Revenues:
Total revenues	152,361	141,848	282,420	270,575
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	110,161	107,447	208,937	212,945
Product | Reportable Legal Entities | Clean Harbors, Inc.
Revenues:
Total revenues	0	0	0	0
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	0	0	0	0
Product | Reportable Legal Entities | Guarantor Subsidiaries
Revenues:
Total revenues	137,891	125,859	259,473	242,509
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	102,442	98,645	197,480	195,150
Product | Reportable Legal Entities | Non-Guarantor Subsidiaries
Revenues:
Total revenues	17,363	18,730	28,813	34,061
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	10,612	11,543	17,323	23,790
Product | Consolidating Adjustments
Revenues:
Total revenues	(2,893)	(2,741)	(5,866)	(5,995)
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	$ (2,893)	$ (2,741)	$ (5,866)	$ (5,995)