Common stock reserved for issuance under the Company's ESPP.

No definition available.

Name:	cmg_CommonStockAuthorizedAndReservedForIssuanceEspp
Namespace Prefix:	cmg_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Common stock authorized for issuance but not yet issued for ESPP

+ References

No definition available.

+ Details

Name:	cmg_CommonStockAuthorizedForIssuanceButNotYetIssuedForEspp
Namespace Prefix:	cmg_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Compensation Related Costs [Line Items]

+ References

No definition available.

+ Details

Name:	cmg_CompensationRelatedCostsLineItems
Namespace Prefix:	cmg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Conditional Target Number Of Shares Earned, Percentage

+ References

No definition available.

+ Details

Name:	cmg_ConditionalTargetNumberOfSharesEarnedPercentage
Namespace Prefix:	cmg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Deferred Compensation Arrangement With Individual Employer Contribution Percentage On First 3 Percent

+ References

No definition available.

+ Details

Name:	cmg_DeferredCompensationArrangementWithIndividualEmployerContributionPercentageOnFirst3Percent
Namespace Prefix:	cmg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Deferred Compensation Arrangement With Individual Employer Contribution Percentage On Next 2 Percent

+ References

No definition available.

+ Details

Name:	cmg_DeferredCompensationArrangementWithIndividualEmployerContributionPercentageOnNext2Percent
Namespace Prefix:	cmg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Deferred compensation arrangement with individual, employer matching contribution of 100 percent

+ References

No definition available.

+ Details

Name:	cmg_DeferredCompensationArrangementWithIndividualEmployerMatchingContributionOf100Percent
Namespace Prefix:	cmg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Deferred compensation arrangement with individual, employer matching contribution of 50 percent

+ References

No definition available.

+ Details

Name:	cmg_DeferredCompensationArrangementWithIndividualEmployerMatchingContributionOf50Percent
Namespace Prefix:	cmg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay, at Which Employer Matches 100 Percent

+ References

No definition available.

+ Details

Name:	cmg_DefinedContributionPlanEmployerMatchingContributionPercentOfEmployeesGrossPayAtWhichEmployerMatches100Percent
Namespace Prefix:	cmg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay, at Which Employer Matches 50 Percent

+ References

No definition available.

+ Details

Name:	cmg_DefinedContributionPlanEmployerMatchingContributionPercentOfEmployeesGrossPayAtWhichEmployerMatches50Percent
Namespace Prefix:	cmg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Defined Contribution Plan, Employer Matching Contribution, Percent of Match On First 3%

+ References

No definition available.

+ Details

Name:	cmg_DefinedContributionPlanEmployerMatchingContributionPercentOfMatchOnFirst3
Namespace Prefix:	cmg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Defined Contribution Plan, Employer Matching Contribution, Percent of Match On Next 2 Percent

+ References

No definition available.

+ Details

Name:	cmg_DefinedContributionPlanEmployerMatchingContributionPercentOfMatchOnNext2Percent
Namespace Prefix:	cmg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum percent an employee may contribute after one year of service with the Company.

+ References

No definition available.

+ Details

Name:	cmg_EsppPercentOfBaseEarnings
Namespace Prefix:	cmg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Eligibility period to contribute to the ESPP.

+ References

No definition available.

+ Details

Name:	cmg_EsppRequisiteServicePeriod
Namespace Prefix:	cmg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Incremental Share-based Compensation, Number of Installments

+ References

No definition available.

+ Details

Name:	cmg_IncrementalShareBasedCompensationNumberOfInstallments
Namespace Prefix:	cmg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Eligibility period to receive matching contributions

+ References

No definition available.

+ Details

Name:	cmg_MatchingContributions401k
Namespace Prefix:	cmg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Employees Terminated Employment

+ References

No definition available.

+ Details

Name:	cmg_NumberOfEmployeesTerminatedEmployment
Namespace Prefix:	cmg_
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	duration

- Definition

Performance and Market Measurement Period

+ References

No definition available.

+ Details

Name:	cmg_PerformanceAndMarketMeasurePeriod
Namespace Prefix:	cmg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Purchase Price Percentage Of Lower Of Fair Market Value Of Stock On First And Last Trading Days Of Each Offering Period

+ References

No definition available.

+ Details

Name:	cmg_PurchasePricePercentageOfLowerOfFairMarketValueOfStockOnFirstAndLastTradingDaysOfEachOfferingPeriod
Namespace Prefix:	cmg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Share-based Payment Arrangement, Plan Modification, Incremental Cost, Unamortized

+ References

No definition available.

+ Details

Name:	cmg_ShareBasedPaymentArrangementPlanModificationIncrementalCostUnamortized
Namespace Prefix:	cmg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479830/718-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

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

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

No definition available.

+ Details

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

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480794/715-70-50-1

+ Details

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

- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(02)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

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

- Definition

Number of shares authorized for issuance under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

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

- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

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

- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

+ Details

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

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

An excess of the fair value of the modified award over the fair value of the award immediately before the modification.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

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

- Definition

Number of grantees affected by modification of award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

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

- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Per share or per unit amount of equity securities issued.

+ References

No definition available.

+ Details

Name:	us-gaap_SharesIssuedPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares issued during the period as a result of an employee stock purchase plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_PlanNameAxis=cmg_StockIncentivePlan2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=cmg_StockOptionsStockAppreciationRightsSosarsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=cmg_StockAwards2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=cmg_FirstHalfVestedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=cmg_SecondHalfVestedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=cmg_DefinedMinimumTargetsNotMetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=cmg_CertainEquityAwardsOfEmployeeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=cmg_SeparationVestingPeriodMember
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:	us-gaap_VestingAxis=cmg_VestingPeriod1Member
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_DeferredCompensationArrangementWithIndividualPostretirementBenefitsByTypeOfDeferredCompensationAxis=us-gaap_EmployeeStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsByTypeOfDeferredCompensationAxis=us-gaap_DomesticPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanNameAxis=cmg_Plan401kMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stock-Based Compensation and Employee Benefit Plans (Narrative) (Details) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Jul. 31, 2022 USD ($) employee shares	Dec. 31, 2023 USD ($) item $ / shares shares	Dec. 31, 2022 USD ($) item $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) employee	Dec. 30, 2020 $ / shares
Compensation Related Costs [Line Items]
Grant date fair value \| $ / shares		$ 530.22	$ 456.44	$ 403.01
Vesting period		3 years
Total liabilities under Deferred Plan		$ 27,178
2022 Stock Incentive Plan [Member]
Compensation Related Costs [Line Items]
Common stock authorized and reserved for issuances \| shares		2,431,000
Common stock remaining available for future issuance \| shares		2,165,000
SOSARs [Member]
Compensation Related Costs [Line Items]
Total intrinsic value of SOSARs exercised		$ 142,830	$ 77,124	$ 498,399
Unearned compensation		$ 28,196
Weighted average period		1 year 6 months
Expiration period of SOSARs		7 years
Restricted Stock Units (RSUs) [Member]
Compensation Related Costs [Line Items]
Unearned compensation		$ 33,680
Weighted average period		1 year 7 months 6 days
Grant date fair value \| $ / shares		$ 1,666.18	$ 1,559.73	$ 1,492.15
Shares vested, fair value		$ 39,464	$ 33,959	$ 73,540
Units vested \| shares		23,000
Units forfeited \| shares		9,000
Performance Shares [Member]
Compensation Related Costs [Line Items]
Unearned compensation		$ 69,610
Weighted average period		1 year 10 months 24 days
Grant date fair value \| $ / shares		$ 1,606.91	$ 1,569.39	$ 1,479.55
Shares vested, fair value		$ 110,794	$ 177,293	$ 97,496
Vesting period		3 years	3 years	3 years
Units vested \| shares		33,000
Performance and market measurement period		3 years	3 years	3 years
Performance Shares [Member] \| 2018 Stock Awards [Member]
Compensation Related Costs [Line Items]
Number of installments \| item			4
Number of employees affected by modified service requirements \| employee					7
Modified service requirements expense					$ 71,441
Stock-based compensation expense			$ 7,255
Modified service requirements expense, unamortized			$ 0
Stock price \| $ / shares						$ 1,374.17
Performance Shares [Member] \| First Half Vested [Member] \| 2018 Stock Awards [Member]
Compensation Related Costs [Line Items]
Units vested \| shares			33,000
Number of installments \| item			2
Performance Shares [Member] \| Second Half Vested [Member] \| 2018 Stock Awards [Member]
Compensation Related Costs [Line Items]
Units vested \| shares		16,000
Number of installments \| item		2
Performance Shares [Member] \| Defined Minimum Targets Not Met [Member]
Compensation Related Costs [Line Items]
Units vested \| shares			0	0
Certain Equity Awards of an Employee [Member]
Compensation Related Costs [Line Items]
Units forfeited \| shares	1,000
Number of employees terminated employment \| employee	1
Number of employees affected by modified service requirements \| employee	1
Modified service requirements expense	$ 6,701
Certain Equity Awards of an Employee [Member] \| Separation Vesting Period [Member]
Compensation Related Costs [Line Items]
Vesting period	8 months
Minimum [Member] \| Performance Shares [Member] \| Vesting Period 1 [Member]
Compensation Related Costs [Line Items]
Percentage of target number of shares to be earned if certain criteria is met		0.00%	0.00%	0.00%
Maximum [Member] \| Performance Shares [Member]
Compensation Related Costs [Line Items]
Percentage of target number of shares to be earned if certain criteria is met				100.00%
Maximum [Member] \| Performance Shares [Member] \| Vesting Period 1 [Member]
Compensation Related Costs [Line Items]
Percentage of target number of shares to be earned if certain criteria is met		300.00%	300.00%	300.00%
Maximum [Member] \| Performance Shares [Member] \| Defined Minimum Targets Not Met [Member]
Compensation Related Costs [Line Items]
Percentage of target number of shares to be earned if certain criteria is met		100.00%	100.00%
Employee Stock Purchase Plan (ESPP) [Member]
Compensation Related Costs [Line Items]
Purchase price percentage of lower of fair market value on first and last trading days of each offering period		92.50%
Common stock authorized and reserved for ESPP \| shares		250,000
Common stock authorized for issuance but not yet issued for ESPP \| shares		248,000
Shares issued under ESPP \| shares		1,000	1,000	1,000
ESPP employee contribution, percentage		15.00%
Period of service before an employee is eligible for contribution		1 year
Deferred Plan [Member]
Compensation Related Costs [Line Items]
Employer matching contribution, percentage on first 3%		100.00%
Employer matching contribution, percentage on next 2%		50.00%
Percentage of employees' gross pay for which the employer contributes a matching contribution of 100% under the Deferred Plan		3.00%
Percentage of employees' gross pay for which the employer contributes a matching contribution of 50% under the Deferred Plan		2.00%
Total liabilities under Deferred Plan		$ 27,178	$ 21,140
401(k) Plan [Member]
Compensation Related Costs [Line Items]
Employer matching contribution, percentage on first 3%		100.00%
Employer matching contribution, percentage on next 2%		50.00%
Percentage of employees' gross pay for which the employer contributes a matching contribution of 100%		3.00%
Percentage of employees' gross pay for which the employer contributes a matching contribution of 50%		2.00%
Period of service before an employee is eligible for contribution		1 year
Company matching contributions		$ 13,821	$ 12,923	$ 10,527