Retirement Programs - Narrative (Details) $ in Millions	12 Months Ended
Dec. 31, 2020 USD ($) employee multiemployerPlan shares	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Retirement Benefits [Abstract]
Number of multiemployer plans participated in \| multiemployerPlan	8
Estimated number of union employees in multiemployer plans \| employee	200
Multiemployer plan contributions \| $	$ 2	$ 2	$ 2
Multiemployer plan, contributions by employer, percentage of employee contributions		1.00%	1.00%
Number of plans in red zone \| multiemployerPlan	4
Number of plans in green zone \| multiemployerPlan	4
Praxair U.S. Defined Contribution Savings Plans
Retirement Programs - Defined Contribution Plans [Line Items]
Maximum amount employees may contribute to the respective plan subject to IRS limitations	40.00%
Defined contribution plan contributions \| $	$ 46	$ 47	$ 33
Shares of common stock in esops (in shares) \| shares	1,872,450
Praxair International Defined Contribution Savings Plans
Retirement Programs - Defined Contribution Plans [Line Items]
Defined contribution plan contributions \| $	$ 106	$ 95	$ 32

Multiemployer Plan, Contributions By Employer, Percentage Of Employee Contributions

No definition available.

Name:	lin_MultiemployerPlanContributionsByEmployerPercentageOfEmployeeContributions
Namespace Prefix:	lin_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Multiemployer Plans, Certified Zone Status, Number Of Plans, Green Zone

+ References

No definition available.

+ Details

Name:	lin_MultiemployerPlansCertifiedZoneStatusNumberOfPlansGreenZone
Namespace Prefix:	lin_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Multiemployer Plans, Certified Zone Status, Number Of Plans, Red Zone

+ References

No definition available.

+ Details

Name:	lin_MultiemployerPlansCertifiedZoneStatusNumberOfPlansRedZone
Namespace Prefix:	lin_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of employees within multiemployer plans

+ References

No definition available.

+ Details

Name:	lin_NumberOfEmployeeInMultiemployerPlan
Namespace Prefix:	lin_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of multiemployer plans that Praxair participates in.

+ References

No definition available.

+ Details

Name:	lin_NumberOfMultiemployerPlansParticipatedIn
Namespace Prefix:	lin_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

Name:	lin_RetirementProgramsDefinedContributionPlansLineItems
Namespace Prefix:	lin_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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

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

- Definition

Sum of the allocated, committed-to-be-released and suspense shares of the entity held by the plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 40
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109244661&loc=d3e17540-113929

+ Details

Name:	us-gaap_EmployeeStockOwnershipPlanESOPSharesInESOP
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of cost for employer contribution to multiemployer plan. Multiemployer plan includes, but is not limited to, pension plan determined to be individually significant and insignificant and other postretirement benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=35742348&loc=SL14450788-114948

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 35
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=29639808&loc=d3e29008-114946

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 9
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450691-114947

+ Details

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

- Details

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

- Details

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