-- None. No documentation exists for this element. --

No definition available.

Name:	clh_LegalAndAdministrativeProceedingsAbstract
Namespace Prefix:	clh_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount as of the balance sheet date of potential needed increase in the loss contingency reserves.

+ References

No definition available.

+ Details

Name:	clh_LossContingencyAccrualAtCarryingValuePotentialAdditionalLiability
Namespace Prefix:	clh_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Loss Contingency, General Damages Sought, Value

+ References

No definition available.

+ Details

Name:	clh_LossContingencyGeneralDamagesSoughtValue
Namespace Prefix:	clh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Loss Contingency, Number of Customers Filing Complaint.

+ References

No definition available.

+ Details

Name:	clh_LossContingencyNumberofCustomersFilingComplaint
Namespace Prefix:	clh_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Loss Contingency, Punitive Damages Sought, Value

+ References

No definition available.

+ Details

Name:	clh_LossContingencyPunitiveDamagesSoughtValue
Namespace Prefix:	clh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The estimated minimum amount of possible loss from the federal and state enforcement actions.

+ References

No definition available.

+ Details

Name:	clh_LossContingencyRangeOfLoss
Namespace Prefix:	clh_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

This element represents the number of municipalities other than Ville Mercier that filed legal proceedings against the Mercier Subsidiary.

+ References

No definition available.

+ Details

Name:	clh_NumberOfNeighboringMunicipalitiesFilingSeparateLegalProceedings
Namespace Prefix:	clh_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of permits that are granted by the government in relation to environmental liabilities.

+ References

No definition available.

+ Details

Name:	clh_NumberOfPermitsIssuedByGovernmentToDumpOrganicLiquid
Namespace Prefix:	clh_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Total costs accrued as of the balance sheet date for environmental loss contingencies.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 25
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6395460&loc=d3e13647-108346

+ Details

Name:	us-gaap_AccrualForEnvironmentalLossContingencies
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of loss contingency liability.

+ References

+ Details

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The number of claims settled and dismissed during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of pending claims pertaining to a loss contingency.

+ References

+ Details

Name:	us-gaap_LossContingencyPendingClaimsNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_BusinessAcquisitionAxis=clh_SafetyKleenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	clh_ContingenciesByNatureOfContingencyAxis=clh_FederalAndStateEnforcementActionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	clh_ContingenciesByNatureOfContingencyAxis=clh_LegalAndAdministrativeProceedingsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	clh_ContingenciesByNatureOfContingencyAxis=clh_VilleMercierMember
Namespace Prefix:
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COMMITMENTS AND CONTINGENCIES (Legal and Administrative Proceedings) (Details) $ in Thousands, CAD in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2010 customer	Dec. 31, 2015 USD ($) claim proceeding	Dec. 31, 2012 CAD	Dec. 31, 1999 municipality	Dec. 31, 1968 permit	Dec. 31, 2014 USD ($) proceeding	Dec. 31, 2013 USD ($)
Legal and Administrative Proceedings
Loss contingency accrual, at carrying value		$ 21,900				$ 33,600
Accrued remedial liabilities		$ 131,992				155,121	$ 172,498
Safety-Kleen
Legal and Administrative Proceedings
Number of proceedings \| proceeding		58
Loss contingency, claims settled and dismissed, claims \| claim		30
Number of customers filing a complaint \| customer	2
Federal and State enforcement actions
Legal and Administrative Proceedings
Reserves relating to legal and administrative proceedings		$ 3,000				$ 5,900
Number of proceedings \| proceeding		6				4
Legal and administrative proceedings
Legal and Administrative Proceedings
Loss contingency accrual, at carrying value		$ 18,900				$ 27,700
Possible increase in legal and administrative proceedings		1,900				$ 2,900
Accrued remedial liabilities		$ 18,900
Ville Mercier
Legal and Administrative Proceedings
Number of permits issued by government, for dumping organic liquid \| permit					2
Number of neighboring municipalities filing separate legal proceedings against the Mercier subsidiary and the government of Quebec \| municipality				3
General damages sought \| CAD			CAD 2.9
Punitive damages sought \| CAD			CAD 10.0