GUARANTOR AND NON-GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION (Consolidating Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Total revenues	$ 843,181	$ 755,846	$ 2,442,099	$ 2,197,575
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	580,685	519,595	1,710,694	1,535,983
Selling, general and administrative expenses	121,219	113,252	362,302	337,767
Accretion of environmental liabilities	2,450	2,347	7,328	7,053
Depreciation and amortization	73,082	72,989	220,686	216,932
Income from operations	65,745	47,663	141,089	99,840
Other expense, net	(996)	(432)	(449)	(2,814)
Loss on early extinguishment of debt	(2,469)	(1,846)	(2,469)	(7,891)
Loss on sale of business	0	(77)	0	31,645
Interest (expense) income, net	(19,916)	(20,675)	(60,955)	(65,743)
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	42,364	24,633	77,216	55,037
(Benefit) provision for income taxes	11,275	12,575	28,011	38,492
Net income	31,089	12,058	49,205	16,545
Other comprehensive income	8,590	23,709	(13,098)	44,858
Comprehensive income	39,679	35,767	36,107	61,403
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	118	19	286	70
Accretion of environmental liabilities	0	0	0	0
Depreciation and amortization	0	0	0	0
Income from operations	(118)	(19)	(286)	(70)
Other expense, net	0	0	0	(222)
Loss on early extinguishment of debt	(2,469)	(1,846)	(2,469)	(7,891)
Loss on sale of business		0		0
Interest (expense) income, net	(20,303)	(21,135)	(62,518)	(66,408)
Equity in earnings of subsidiaries, net of taxes	47,570	25,858	96,202	61,388
Intercompany interest income (expense)	0	0	0	0
Income before (benefit) provision for income taxes	24,680	2,858	30,929	(13,203)
(Benefit) provision for income taxes	(6,409)	(9,200)	(18,276)	(29,748)
Net income	31,089	12,058	49,205	16,545
Other comprehensive income	8,590	23,709	(13,098)	44,858
Comprehensive income	39,679	35,767	36,107	61,403
Reportable Legal Entities | Guarantor Subsidiaries
Revenues:
Total revenues	688,754	600,783	1,974,231	1,761,398
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	468,712	403,644	1,356,016	1,199,899
Selling, general and administrative expenses	101,703	92,299	300,568	276,974
Accretion of environmental liabilities	2,199	2,092	6,569	6,328
Depreciation and amortization	53,764	50,917	160,332	154,754
Income from operations	62,376	51,831	150,746	123,443
Other expense, net	(609)	(305)	(425)	(2,100)
Loss on early extinguishment of debt	0	0	0	0
Loss on sale of business		(77)		31,645
Interest (expense) income, net	195	517	938	876
Equity in earnings of subsidiaries, net of taxes	260	(5,620)	(17,572)	(32,776)
Intercompany interest income (expense)	199	1,372	2,644	3,937
Income before (benefit) provision for income taxes	62,421	47,718	136,331	125,025
(Benefit) provision for income taxes	15,543	20,824	42,872	62,442
Net income	46,878	26,894	93,459	62,583
Other comprehensive income	8,590	23,709	(13,098)	44,858
Comprehensive income	55,468	50,603	80,361	107,441
Reportable Legal Entities | Non-Guarantor Subsidiaries
Revenues:
Total revenues	172,659	172,432	519,308	485,488
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	130,205	133,320	406,118	385,395
Selling, general and administrative expenses	19,398	20,934	61,448	60,723
Accretion of environmental liabilities	251	255	759	725
Depreciation and amortization	19,318	22,072	60,354	62,178
Income from operations	3,487	(4,149)	(9,371)	(23,533)
Other expense, net	(387)	(127)	(24)	(492)
Loss on early extinguishment of debt	0	0	0	0
Loss on sale of business		0		0
Interest (expense) income, net	192	(57)	625	(211)
Equity in earnings of subsidiaries, net of taxes	0	0	0	0
Intercompany interest income (expense)	(199)	(1,372)	(2,644)	(3,937)
Income before (benefit) provision for income taxes	3,093	(5,705)	(11,414)	(28,173)
(Benefit) provision for income taxes	2,141	951	3,415	5,798
Net income	952	(6,656)	(14,829)	(33,971)
Other comprehensive income	0	20,263	(24,442)	38,132
Comprehensive income	952	13,607	(39,271)	4,161
Consolidating Adjustments
Revenues:
Total revenues	(18,232)	(17,369)	(51,440)	(49,311)
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	(18,232)	(17,369)	(51,440)	(49,311)
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 expense, net	0	0	0	0
Loss on early extinguishment of debt	0	0	0	0
Loss on sale of business		0		0
Interest (expense) income, net	0	0	0	0
Equity in earnings of subsidiaries, net of taxes	(47,830)	(20,238)	(78,630)	(28,612)
Intercompany interest income (expense)	0	0	0	0
Income before (benefit) provision for income taxes	(47,830)	(20,238)	(78,630)	(28,612)
(Benefit) provision for income taxes	0	0	0	0
Net income	(47,830)	(20,238)	(78,630)	(28,612)
Other comprehensive income	(8,590)	(43,972)	37,540	(82,990)
Comprehensive income	(56,420)	(64,210)	(41,090)	(111,602)
Service
Revenues:
Total revenues	685,183	612,352	2,001,681	1,783,506
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	464,612	412,369	1,385,684	1,215,812
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	547,997	473,428	1,574,001	1,391,534
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	359,703	306,291	1,049,527	907,396
Service | Reportable Legal Entities | Non-Guarantor Subsidiaries
Revenues:
Total revenues	152,007	152,997	469,843	431,992
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	119,730	120,151	378,320	348,436
Service | Consolidating Adjustments
Revenues:
Total revenues	(14,821)	(14,073)	(42,163)	(40,020)
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	(14,821)	(14,073)	(42,163)	(40,020)
Product
Revenues:
Total revenues	157,998	143,494	440,418	414,069
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	116,073	107,226	325,010	320,171
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	140,757	127,355	400,230	369,864
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	109,009	97,353	306,489	292,503
Product | Reportable Legal Entities | Non-Guarantor Subsidiaries
Revenues:
Total revenues	20,652	19,435	49,465	53,496
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	10,475	13,169	27,798	36,959
Product | Consolidating Adjustments
Revenues:
Total revenues	(3,411)	(3,296)	(9,277)	(9,291)
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	$ (3,411)	$ (3,296)	$ (9,277)	$ (9,291)