GUARANTOR AND NON-GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION (Consolidating Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Service revenues	$ 612,352	$ 594,225	$ 1,783,506	$ 1,709,018
Product revenues	143,494	135,295	414,069	354,095
Total revenues	755,846	729,520	2,197,575	2,063,113
Cost of revenues (exclusive of items shown separately below)
Service cost of revenues	412,369	385,542	1,215,812	1,148,212
Product cost of revenues	107,226	106,373	320,171	287,984
Total cost of revenues	519,595	491,915	1,535,983	1,436,196
Selling, general and administrative expenses	113,252	110,954	337,767	322,501
Accretion of environmental liabilities	2,347	2,476	7,053	7,529
Depreciation and amortization	72,989	73,360	216,932	215,655
Goodwill impairment charge	0	34,013	0	34,013
Income from operations	47,663	16,802	99,840	47,219
Unrealized holding gains on available-for-sale investments	(432)	(198)	(2,814)	(737)
Loss on early extinguishment of debt	(1,846)	0	(7,891)	0
(Loss) gain on sale of businesses	(77)	16,431	31,645	16,431
Interest (expense) income	(20,675)	(21,565)	(65,743)	(62,192)
Equity in earnings of subsidiaries, net of taxes	0	0	0	0
Intercompany interest income (expense)	0	0	0	0
Income (loss) before (benefit) provision for income taxes	24,633	11,470	55,037	721
(Benefit) provision for income taxes	12,575	21,725	38,492	27,881
Net income (loss)	12,058	(10,255)	16,545	(27,160)
Other comprehensive income	23,709	(1,311)	44,858	43,348
Comprehensive income (loss)	35,767	(11,566)	61,403	16,188
Reportable Legal Entities | Clean Harbors, Inc.
Revenues:
Service revenues	0	0	0	0
Product revenues	0	0	0	0
Total revenues	0	0	0	0
Cost of revenues (exclusive of items shown separately below)
Service cost of revenues	0	(598)	0	(1,185)
Product cost of revenues	0	0	0	0
Total cost of revenues	0	(598)	0	(1,185)
Selling, general and administrative expenses	19	23	70	84
Accretion of environmental liabilities	0	0	0	0
Depreciation and amortization	0	0	0	0
Goodwill impairment charge		0		0
Income from operations	(19)	575	(70)	1,101
Unrealized holding gains on available-for-sale investments	0	0	(222)	0
Loss on early extinguishment of debt	(1,846)		(7,891)
(Loss) gain on sale of businesses	0	0	0	0
Interest (expense) income	(21,135)	(23,042)	(66,408)	(66,147)
Equity in earnings of subsidiaries, net of taxes	25,858	3,225	61,388	11,867
Intercompany interest income (expense)	0	0	0	0
Income (loss) before (benefit) provision for income taxes	2,858	(19,242)	(13,203)	(53,179)
(Benefit) provision for income taxes	(9,200)	(8,987)	(29,748)	(26,019)
Net income (loss)	12,058	(10,255)	16,545	(27,160)
Other comprehensive income	23,709	(1,311)	44,858	43,348
Comprehensive income (loss)	35,767	(11,566)	61,403	16,188
Reportable Legal Entities | Guarantor Subsidiaries
Revenues:
Service revenues	473,428	461,139	1,391,534	1,345,629
Product revenues	127,355	118,106	369,864	303,342
Total revenues	600,783	579,245	1,761,398	1,648,971
Cost of revenues (exclusive of items shown separately below)
Service cost of revenues	306,291	288,764	907,396	864,071
Product cost of revenues	97,353	94,050	292,503	252,512
Total cost of revenues	403,644	382,814	1,199,899	1,116,583
Selling, general and administrative expenses	92,299	88,652	276,974	253,189
Accretion of environmental liabilities	2,092	2,243	6,328	6,846
Depreciation and amortization	50,917	51,957	154,754	151,348
Goodwill impairment charge		0		0
Income from operations	51,831	53,579	123,443	121,005
Unrealized holding gains on available-for-sale investments	(305)	(188)	(2,100)	124
Loss on early extinguishment of debt	0		0
(Loss) gain on sale of businesses	(77)	1,288	31,645	1,288
Interest (expense) income	517	1,456	876	3,851
Equity in earnings of subsidiaries, net of taxes	(5,620)	(22,341)	(32,776)	(58,031)
Intercompany interest income (expense)	1,372	5,235	3,937	15,891
Income (loss) before (benefit) provision for income taxes	47,718	39,029	125,025	84,128
(Benefit) provision for income taxes	20,824	35,803	62,442	72,260
Net income (loss)	26,894	3,226	62,583	11,868
Other comprehensive income	23,709	(1,311)	44,858	43,348
Comprehensive income (loss)	50,603	1,915	107,441	55,216
Reportable Legal Entities | Non-Guarantor Subsidiaries
Revenues:
Service revenues	152,997	145,780	431,992	399,216
Product revenues	19,435	20,072	53,496	58,176
Total revenues	172,432	165,852	485,488	457,392
Cost of revenues (exclusive of items shown separately below)
Service cost of revenues	120,151	110,070	348,436	321,153
Product cost of revenues	13,169	15,206	36,959	42,895
Total cost of revenues	133,320	125,276	385,395	364,048
Selling, general and administrative expenses	20,934	22,279	60,723	69,228
Accretion of environmental liabilities	255	233	725	683
Depreciation and amortization	22,072	21,403	62,178	64,307
Goodwill impairment charge		34,013		34,013
Income from operations	(4,149)	(37,352)	(23,533)	(74,887)
Unrealized holding gains on available-for-sale investments	(127)	(10)	(492)	(861)
Loss on early extinguishment of debt	0		0
(Loss) gain on sale of businesses	0	15,143	0	15,143
Interest (expense) income	(57)	21	(211)	104
Equity in earnings of subsidiaries, net of taxes	0	0	0	0
Intercompany interest income (expense)	(1,372)	(5,235)	(3,937)	(15,891)
Income (loss) before (benefit) provision for income taxes	(5,705)	(27,433)	(28,173)	(76,392)
(Benefit) provision for income taxes	951	(5,091)	5,798	(18,360)
Net income (loss)	(6,656)	(22,342)	(33,971)	(58,032)
Other comprehensive income	20,263	(3,927)	38,132	24,403
Comprehensive income (loss)	13,607	(26,269)	4,161	(33,629)
Consolidating Adjustments
Revenues:
Service revenues	(14,073)	(12,694)	(40,020)	(35,827)
Product revenues	(3,296)	(2,883)	(9,291)	(7,423)
Total revenues	(17,369)	(15,577)	(49,311)	(43,250)
Cost of revenues (exclusive of items shown separately below)
Service cost of revenues	(14,073)	(12,694)	(40,020)	(35,827)
Product cost of revenues	(3,296)	(2,883)	(9,291)	(7,423)
Total cost of revenues	(17,369)	(15,577)	(49,311)	(43,250)
Selling, general and administrative expenses	0	0	0	0
Accretion of environmental liabilities	0	0	0	0
Depreciation and amortization	0	0	0	0
Goodwill impairment charge		0		0
Income from operations	0	0	0	0
Unrealized holding gains on available-for-sale investments	0	0	0	0
Loss on early extinguishment of debt	0		0
(Loss) gain on sale of businesses	0	0	0
Interest (expense) income	0	0	0	0
Equity in earnings of subsidiaries, net of taxes	(20,238)	19,116	(28,612)	46,164
Intercompany interest income (expense)	0	0	0	0
Income (loss) before (benefit) provision for income taxes	(20,238)	19,116	(28,612)	46,164
(Benefit) provision for income taxes	0	0	0	0
Net income (loss)	(20,238)	19,116	(28,612)	46,164
Other comprehensive income	(43,972)	5,238	(82,990)	(67,751)
Comprehensive income (loss)	$ (64,210)	$ 24,354	$ (111,602)	$ (21,587)