This item represents the total estimated future development costs for a specified development project.

No definition available.

Name:	nhi_EstimatedFutureDevelopmentCost
Namespace Prefix:	nhi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The inital lease amount charged under a lease entered into in connection with the purchase of property.

+ References

No definition available.

+ Details

Name:	nhi_InitialLeaseAmount
Namespace Prefix:	nhi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

This item represents the percentage of ownership interest which is retained subsequent to contribution into a joint venture.

+ References

No definition available.

+ Details

Name:	nhi_JointVentureContributedPropertiesOwnershipInterestRetained
Namespace Prefix:	nhi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This item represents the percentage of ownership interest which is surrendered subsequent to contribution into a joint venture.

+ References

No definition available.

+ Details

Name:	nhi_JointVentureContributedPropertiesOwnershipInterestSurrendered
Namespace Prefix:	nhi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The initial escalator rate charged from lease year 3 through the end of the lease term under a lease entered into in connection with the purchase of a property.

+ References

No definition available.

+ Details

Name:	nhi_LeaseEscalatorRateAfterLeaseYear3
Namespace Prefix:	nhi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The initial lease escalator to be charged starting after lease year 4 under a lease entered into in connection with the purchase of a property.

+ References

No definition available.

+ Details

Name:	nhi_LeaseEscalatorRateafterLeaseYear4
Namespace Prefix:	nhi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The initial escalator rate charged from lease year 1 and through lease year 3 under a lease entered into in connection with the purchase of a property.

+ References

No definition available.

+ Details

Name:	nhi_LeaseEscalatorRateFromLeaseYear1toLeaseYear3
Namespace Prefix:	nhi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The initial lease escalator rate charged from lease year 2 through lease year 4 under a lease entered into in connection with the purchase of a property.

+ References

No definition available.

+ Details

Name:	nhi_LeaseEscalatorRateLeaseYear2toLeaseYear4
Namespace Prefix:	nhi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the minimum annual lease income to be received.

+ References

No definition available.

+ Details

Name:	nhi_MinimumAnnualLeaseIncome
Namespace Prefix:	nhi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This item represents the original cost of corporate assets that are not part of the investment portfolio.

+ References

No definition available.

+ Details

Name:	nhi_NonportfolioAssetsOriginalCost
Namespace Prefix:	nhi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number Of Additional Lease Renewal Options

+ References

No definition available.

+ Details

Name:	nhi_NumberOfAdditionalLeaseRenewalOptions
Namespace Prefix:	nhi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of lessees of real estate property at the end of the period.

+ References

No definition available.

+ Details

Name:	nhi_NumberOfLessees
Namespace Prefix:	nhi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of Master Leases

+ References

No definition available.

+ Details

Name:	nhi_NumberofMasterLeases
Namespace Prefix:	nhi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number Of Real Estate Properties Acquired

+ References

No definition available.

+ Details

Name:	nhi_NumberOfRealEstatePropertiesAcquired
Namespace Prefix:	nhi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the number of real estate properties to be constructed, based on an agreement or commitment.

+ References

No definition available.

+ Details

Name:	nhi_NumberOfRealEstatePropertiesToBeConstructed
Namespace Prefix:	nhi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the percentage of income recognized from a lease tenant.

+ References

No definition available.

+ Details

Name:	nhi_PercentageOfContinuingRevenue
Namespace Prefix:	nhi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the rental revenue rate earned during the period from lessee-operators based on revenues generated in their operations, generally in excess of a base amount. Generally stipulated in the lease agreement, it usually will provide for a fixed percentage of revenue to be paid as additional (or possibly only) rent due the lessor, and may be based on gross revenues, net revenues, or multiple variations thereof.

+ References

No definition available.

+ Details

Name:	nhi_PercentageRentRate
Namespace Prefix:	nhi_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

This item represents the amount of an outstanding purchase option.

+ References

No definition available.

+ Details

Name:	nhi_PurchaseOptionAmount
Namespace Prefix:	nhi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The element represents the original cost of all portfolio leased assets.

+ References

No definition available.

+ Details

Name:	nhi_RealEstateInvestmentPropertyPortfolioAssets
Namespace Prefix:	nhi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

+ Details

Name:	us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The current amount of expenditures for a real estate project that has not yet been completed.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.10)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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

- Definition

Term of the lessor's leasing arrangement renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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

- Definition

Term of the lessor's leasing arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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

- Definition

The number of real estate properties owned as of the balance sheet date.

+ References

No definition available.

+ Details

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

- Definition

The number of states the entity operates in as of the balance sheet date.

+ References

No definition available.

+ Details

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

- Definition

The number of units in a real estate property owned as of the balance sheet date.

+ References

No definition available.

+ Details

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

- Definition

Future rental payments receivable within one year of the balance sheet date under an operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718

+ Details

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

- Definition

The total amount of revenue recognized for the period from operating leases, including minimum lease revenue, contingent revenue, percentage revenue and sublease revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 20

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=7501430&loc=d3e39896-112707

+ Details

Name:	us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents the rental revenue earned during the period from lessee-operators based on revenues generated in their operations, generally in excess of a base amount. Such rental revenue is generally stipulated in the lease agreement, usually will provide for a fixed percentage of revenue to be paid as additional (or possibly only) rent due the lessor, and may be based on gross revenues, net revenues, or multiple variations thereof. Percentage rent is often required under leases with retail outlets located on premises owned by hoteliers, cruise lines, others in the hospitality industry, and shopping mall operators, among others.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1(e))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

Name:	us-gaap_PercentageRent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of an asset, typically cash, provided to a counterparty to provide certain assurance of performance by the entity pursuant to the terms of a written or oral agreement, such as a lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.8,17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Difference between actual rental income due and rental income recognized on a straight-line basis.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

+ Details

Name:	us-gaap_StraightLineRent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=nhi_RIDEAJVOperatingEntityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	invest_InvestmentAxis=nhi_A2015BickfordDevelopmentPropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	invest_InvestmentAxis=nhi_BickfordDevelopmentPropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	nhi_FacilityTypeAxis=nhi_SeniorHousingCommunityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorCustomersAxis=nhi_BickfordSeniorLivingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorCustomersAxis=nhi_HolidayAcquisitionHoldingsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorCustomersAxis=nhi_NationalHealthcareCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=nhi_HospitalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=nhi_IndependentLivingFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=nhi_MedicalOfficeBuildingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=nhi_SeniorHousingCommunityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=nhi_SkilledNursingFacilityMember
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Real Estate (Narrative) (Details) (USD $)	3 Months Ended
Real Estate (Narrative) (Details) (USD $)	Mar. 31, 2015 properties	Mar. 31, 2014	Dec. 31, 2014
Number of Real Estate Properties	172us-gaap_NumberOfRealEstateProperties
Number of States in which Entity Operates	31
Nonportfolio Assets, Original Cost	$ 910,000nhi_NonportfolioAssetsOriginalCost
Real Estate Investment Property, Portfolio Assets	1,991,266,000
Number of Lessees	24nhi_NumberOfLessees
Security Deposit	21,275,000us-gaap_SecurityDeposit		21,648,000us-gaap_SecurityDeposit
Operating Leases, Income Statement, Lease Revenue	52,495,000	40,313,000
Percentage of Continuing Revenue	18.00%nhi_PercentageOfContinuingRevenue
Straight Line Rent	6,089,000us-gaap_StraightLineRent	4,195,000us-gaap_StraightLineRent
Lease Renewal Period In Years	5 years 0 months 0 days
Bickford Development Properties [Member]
Number of Units in Real Estate Property	60
Number of Real Estate Properties To Be Constructed	8
2015 Bickford Development Properties [Member]
Number of Units in Real Estate Property	60
Estimated Future Development Cost	55,000,000
Number of Real Estate Properties To Be Constructed	5
Holiday Acquisition Holdings [Member]
Number of Real Estate Properties	25
Lessor Leasing Arrangements, Operating Leases, Term of Contract	17 years 0 months 0 days
Lease Escalator Rate, From Lease Year 1 to Lease Year 3	4.50%
Lease Escalator Rate, After Lease Year 3	3.50%
Operating Leases, Income Statement, Lease Revenue	10,954,000	10,954,000
Percentage of Continuing Revenue	20.00%	25.00%
Straight Line Rent	2,616,000	2,975,000
Minimum Annual Lease Income	33,351,000
National Healthcare Corporation [Member]
Number of Real Estate Properties	42
Number of Master Leases	2
Operating Leases, Income Statement, Lease Revenue	9,227,000	9,118,000
Percentage of Continuing Revenue	17.00%	21.00%
Percentage rent	690,000	581,000
National Healthcare Corporation [Member] \| NHC - 1991 Lease [Member]
Number of Real Estate Properties	35
Number of additional lease renewal options	2
Lease Renewal Period In Years	5 years 0 months 0 days
Percentage Rent Rate	0.04
Minimum Annual Lease Income	30,750,000
National Healthcare Corporation [Member] \| NHC - 2013 Lease [Member]
Number Of Real Estate Properties Acquired	7
Minimum Annual Lease Income	3,450,000
Purchase Option Amount	49,000,000
Bickford Senior Living [Member]
Number of Real Estate Properties	36
Development in Process	941,000
Operating Leases, Future Minimum Payments Receivable, Current	23,195,000
Number of States in which Entity Operates	8
Operating Leases, Income Statement, Lease Revenue	5,804,000	5,263,000
Percentage of Continuing Revenue	10.00%	12.00%
Joint Venture Contributed Properties Ownership Interest Retained	85.00%
Joint Venture Contributed Properties Ownership Interest Surrendered	15.00%
Senior Housing Community [Member]
Number of Real Estate Properties	103
Skilled Nursing Facility [Member]
Number of Real Estate Properties	64
Skilled Nursing Facility [Member] \| National Healthcare Corporation [Member]
Number of Real Estate Properties	39
Skilled Nursing Facility [Member] \| National Healthcare Corporation [Member] \| Subleased Facilities [Member]
Number of Real Estate Properties	4
Hospital [Member]
Number of Real Estate Properties	3
Medical Office Building [Member]
Number of Real Estate Properties	2
Independent Living Facility [Member] \| National Healthcare Corporation [Member]
Number of Real Estate Properties	3
RIDEA JV Operating Entity [Member] \| Bickford Senior Living [Member]
Joint Venture Contributed Properties Ownership Interest Retained	85.00%
Senior Housing Community [Member] \| Senior Living Communities [Member]
Number of Units in Real Estate Property	1,671
Lessor Leasing Arrangements, Operating Leases, Term of Contract	15 years 0 months 0 days
Security Deposit	10,000,000
Initial Lease Amount	31,000,000
Lease Escalator Rate Lease Year 2 to Lease Year 4	4.00%
Lease Escalator Rate after Lease Year 4	3.00%
Number Of Real Estate Properties Acquired	8
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	9,855,000
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual	$ 4,596,000
Number of additional lease renewal options	2