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

No definition available.

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

- Definition

This item represents the maximum rate by which a lease will annually increase.

+ References

No definition available.

+ Details

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

- Definition

This item represents the minimum rate by which a lease will annually increase.

+ References

No definition available.

+ Details

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

- Definition

This item represents the value received in a modification of a real estate lease.

+ References

No definition available.

+ Details

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

- Definition

The cumulative difference between the rental payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property, expected to be recognized in income or expense over the term of the leased property, by the lessor or lessee, respectively. Such receivable is reduced by allowances attributable to, for instance, credit risk associated with a lessee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 35
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=77913719&loc=d3e40879-112712

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 25
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=77902458&loc=d3e39927-112707

Reference 3: 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)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: 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=77902458&loc=d3e39896-112707

+ Details

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

- Definition

The designation of funds furnished by a borrower to a lender to assure future payments of the borrower's real estate taxes and insurance obligations with respect to a mortgaged property. Escrow deposits may be made for a variety of other purposes such as earnest money and contingent payments. This element excludes replacement reserves which are an escrow separately provided for within the US GAAP taxonomy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- 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 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=77902458&loc=d3e39896-112707

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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

- Details

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

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
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:

Subsequent Events Subsequent Events (Narrative) (Details)		3 Months Ended		9 Months Ended
	Nov. 04, 2018 USD ($)	Sep. 30, 2018 USD ($) properties	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) properties	Sep. 30, 2017 USD ($)	Nov. 05, 2018 USD ($) properties	Oct. 01, 2018 USD ($)	Dec. 31, 2017 USD ($)
Subsequent Event [Line Items]
Number of Real Estate Properties \| properties		219		219
Escrow Deposit		$ 8,208,000		$ 8,208,000				$ 8,208,000
Minimum Annual Lease Income		71,688,000	$ 68,204,000	210,809,000	$ 197,077,000
Deferred Rent Receivables, Net		$ 114,397,000		$ 114,397,000				$ 97,359,000
SH Regency Leasing LLC [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Deferred Rent Receivables, Net							$ 1,820,000
Holiday Acquisition Holdings [Member]
Subsequent Event [Line Items]
Number of Real Estate Properties \| properties		25		25
Minimum Annual Lease Income		$ 10,954,000	$ 10,954,000	$ 32,863,000	$ 32,863,000
Deferred Rent Receivables, Net		$ 43,614,000		$ 43,614,000
Holiday Acquisition Holdings [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Value Received in Real Estate Lease Modification						$ 65,762,000
Initial Lease Amount						$ 31,500,000
Number of Real Estate Properties \| properties						25
Lease Escalator Rate, Minimum						2.00%
Lease Escalator Rate, Maximum						3.00%
Escrow Deposit						$ 21,275,000
Minimum Annual Lease Income	$ 39,014,000