Represents the percent of cash balance benefits related to participation in the plan.

No definition available.

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Namespace Prefix:	ecl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of eligible compensation by employee before tax contribution, 100% matched by employer.

+ References

No definition available.

+ Details

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- Definition

Percentage of eligible compensation by employee before tax contribution, 50% matched by employer.

+ References

No definition available.

+ Details

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Namespace Prefix:	ecl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of matching contribution by company vested immediately under a 401(k) savings plan.

+ References

No definition available.

+ Details

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Namespace Prefix:	ecl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employer matching contribution when employee before tax contribution is up to 3% of eligible compensation.

+ References

No definition available.

+ Details

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Namespace Prefix:	ecl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employer matching contribution when employee before tax contribution is between 3% to 5% of eligible compensation.

+ References

No definition available.

+ Details

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Namespace Prefix:	ecl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employer matching contribution when employee before tax contribution is between 4% to 8% of eligible compensation.

+ References

No definition available.

+ Details

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Namespace Prefix:	ecl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employer matching contribution when employee before tax contribution is up to 4% of eligible compensation.

+ References

No definition available.

+ Details

Name:	ecl_PercentageOfMatchingContributionMadeByCompanyUpTo4Percent
Namespace Prefix:	ecl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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

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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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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- Details

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- Details

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Balance Type:
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- Details

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Namespace Prefix:
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RETIREMENT PLANS - Savings Plan and ESOP (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Contribution Plan Disclosure [Line Items]
Percentage of matching contribution by company vested immediately	100.00%
Employer matching contribution expense	$ 72	$ 76	$ 72
Traditional Plan
Defined Contribution Plan Disclosure [Line Items]
Cash balance benefits percentage	5.00%
Percentage of matching contribution made by company, up to 3% eligible compensation	100.00%
Percentage of matching contribution made by company for employee contributions between 3% and 5%	50.00%
Ecolab Plan
Defined Contribution Plan Disclosure [Line Items]
Cash balance benefits percentage	3.00%
Percentage of matching contribution made by company, up to 4% eligible compensation	100.00%
Percentage of matching contribution made by company for employee contributions between 4% and 8%	50.00%
Minimum \| Traditional Plan
Defined Contribution Plan Disclosure [Line Items]
Percentage of eligible compensation, matched 50%	3.00%
Minimum \| Ecolab Plan
Defined Contribution Plan Disclosure [Line Items]
Percentage of eligible compensation, matched 50%	4.00%
Maximum \| Traditional Plan
Defined Contribution Plan Disclosure [Line Items]
Percentage of eligible compensation, matched 100%	3.00%
Percentage of eligible compensation, matched 50%	5.00%
Maximum \| Ecolab Plan
Defined Contribution Plan Disclosure [Line Items]
Percentage of eligible compensation, matched 100%	4.00%
Percentage of eligible compensation, matched 50%	8.00%