Represents the number of multi-employer defined benefit pension plans in which reporting entity is a participant.

No definition available.

Name:	ecol_NumberOfMultiemployerPlans
Namespace Prefix:	ecol_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cost for employer contribution to multiemployer pension plan determined to be individually insignificant.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 9
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-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450691-114947

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-Publisher FASB
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+ Details

Name:	us-gaap_MultiemployerPlanPensionInsignificantEmployerContributionCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cost for employer contribution to multiemployer pension plan determined to be individually significant.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 5
-Subparagraph (e)(1)
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+ Details

Name:	us-gaap_MultiemployerPlanPensionSignificantEmployerContributionCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_RetirementPlanNameAxis=ecol_SavingsAndRetirementPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanNameAxis=ecol_NrcSavingsAndRetirementPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanNameAxis=ecol_MultiEmployerDefinedBenefitPensionPlansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanNameAxis=ecol_OperatingEngineersLocal324PensionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollectiveBargainingArrangementAxis=ecol_CommunicationsEnergyAndPaperworkersUnionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollectiveBargainingArrangementAxis=us-gaap_LaborForceConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanNameAxis=ecol_SimplifiedPensionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

EMPLOYEE BENEFIT PLANS (Details)	12 Months Ended
EMPLOYEE BENEFIT PLANS (Details)	Dec. 31, 2021 USD ($) plan	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Defined contribution plans
Individually insignificant contributions made	$ 157,000	$ 205,000
The Plan
Defined contribution plans
Entity's matching contribution (as a percent)	55.00%
Company's contribution as a percentage of eligible compensation	6.00%
Entity's matching contributions to the Plan	$ 6,400,000	3,300,000	$ 3,000,000.0
The NRC Plans
Defined contribution plans
Entity's matching contributions to the Plan		2,300,000	325,000
Multi-employer Defined Benefit Pension Plans
Defined contribution plans
Number of multi-employer plans \| plan	4
Operating Engineers Local 324 Pension Plan
Defined contribution plans
Significant contribution made	$ 1,100,000	1,000,000.0
Communications, Energy and Paperworkers Union of Canada \| Minimum
Defined contribution plans
Company's contribution as a percentage of eligible compensation	5.00%
Communications, Energy and Paperworkers Union of Canada \| Maximum
Defined contribution plans
Company's contribution as a percentage of eligible compensation	9.50%
Non-unionized employees \| The SPP
Defined contribution plans
Entity's matching contributions to the Plan	$ 858,000	$ 782,000	$ 719,000