GUARANTOR AND NON-GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION (Consolidating Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues:
Total revenues	$ 780,839	$ 749,778
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	564,364	546,425
Selling, general and administrative expenses	114,812	115,088
Accretion of environmental liabilities	2,574	2,430
Depreciation and amortization	75,355	74,844
Income from operations	23,734	10,991
Other income (expense), net	2,983	(299)
Interest (expense) income, net	(19,764)	(20,270)
Equity in earnings of subsidiaries, net of taxes	0	0
Intercompany interest income (expense)	0	0
Income (loss) before provision for income taxes	6,953	(9,578)
(Benefit) provision for income taxes	5,977	3,053
Net income (loss)	976	(12,631)
Other comprehensive income	4,024	(16,746)
Comprehensive income (loss)	5,000	(29,377)
Reportable Legal Entities | Clean Harbors, Inc.
Revenues:
Total revenues	0	0
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	0	0
Selling, general and administrative expenses	57	35
Accretion of environmental liabilities	0	0
Depreciation and amortization	0	0
Income from operations	(57)	(35)
Other income (expense), net	50	0
Interest (expense) income, net	(20,374)	(20,999)
Equity in earnings of subsidiaries, net of taxes	15,636	2,514
Intercompany interest income (expense)	0	0
Income (loss) before provision for income taxes	(4,745)	(18,520)
(Benefit) provision for income taxes	(5,721)	(5,889)
Net income (loss)	976	(12,631)
Other comprehensive income	4,024	(16,746)
Comprehensive income (loss)	5,000	(29,377)
Reportable Legal Entities | Guarantor Subsidiaries
Revenues:
Total revenues	644,694	603,065
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	455,947	423,218
Selling, general and administrative expenses	93,526	93,843
Accretion of environmental liabilities	2,267	2,176
Depreciation and amortization	57,335	53,704
Income from operations	35,619	30,124
Other income (expense), net	2,962	(85)
Interest (expense) income, net	9	505
Equity in earnings of subsidiaries, net of taxes	(13,336)	(20,062)
Intercompany interest income (expense)	197	1,361
Income (loss) before provision for income taxes	25,451	11,843
(Benefit) provision for income taxes	11,418	9,101
Net income (loss)	14,033	2,742
Other comprehensive income	4,024	(16,746)
Comprehensive income (loss)	18,057	(14,004)
Reportable Legal Entities | Non-Guarantor Subsidiaries
Revenues:
Total revenues	156,523	163,851
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	128,795	140,345
Selling, general and administrative expenses	21,229	21,210
Accretion of environmental liabilities	307	254
Depreciation and amortization	18,020	21,140
Income from operations	(11,828)	(19,098)
Other income (expense), net	(29)	(214)
Interest (expense) income, net	601	224
Equity in earnings of subsidiaries, net of taxes	0	0
Intercompany interest income (expense)	(197)	(1,361)
Income (loss) before provision for income taxes	(11,453)	(20,449)
(Benefit) provision for income taxes	280	(159)
Net income (loss)	(11,733)	(20,290)
Other comprehensive income	8,328	(14,007)
Comprehensive income (loss)	(3,405)	(34,297)
Consolidating Adjustments
Revenues:
Total revenues	(20,378)	(17,138)
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	(20,378)	(17,138)
Selling, general and administrative expenses	0	0
Accretion of environmental liabilities	0	0
Depreciation and amortization	0	0
Income from operations	0	0
Other income (expense), net	0	0
Interest (expense) income, net	0	0
Equity in earnings of subsidiaries, net of taxes	(2,300)	17,548
Intercompany interest income (expense)	0	0
Income (loss) before provision for income taxes	(2,300)	17,548
(Benefit) provision for income taxes	0	0
Net income (loss)	(2,300)	17,548
Other comprehensive income	(12,352)	30,753
Comprehensive income (loss)	(14,652)	48,301
Service
Revenues:
Total revenues	656,658	619,719
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	463,483	447,649
Service | Reportable Legal Entities | Clean Harbors, Inc.
Revenues:
Total revenues	0	0
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	0	0
Service | Reportable Legal Entities | Guarantor Subsidiaries
Revenues:
Total revenues	529,656	481,483
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	356,590	328,180
Service | Reportable Legal Entities | Non-Guarantor Subsidiaries
Revenues:
Total revenues	144,139	152,401
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	124,030	133,634
Service | Consolidating Adjustments
Revenues:
Total revenues	(17,137)	(14,165)
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	(17,137)	(14,165)
Product
Revenues:
Total revenues	124,181	130,059
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	100,881	98,776
Product | Reportable Legal Entities | Clean Harbors, Inc.
Revenues:
Total revenues	0	0
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	0	0
Product | Reportable Legal Entities | Guarantor Subsidiaries
Revenues:
Total revenues	115,038	121,582
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	99,357	95,038
Product | Reportable Legal Entities | Non-Guarantor Subsidiaries
Revenues:
Total revenues	12,384	11,450
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	4,765	6,711
Product | Consolidating Adjustments
Revenues:
Total revenues	(3,241)	(2,973)
Cost of revenues: (exclusive of items shown separately below)
Total cost of revenues	$ (3,241)	$ (2,973)