Mortgage And Other Notes Receivable Mortgage and Other Notes Receivable (Schedule of Bickford Construction Loans) (Details) - USD ($)	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Commitments, Fixed Rates	$ 103,000,000
Loans and Leases Receivable, Net Amount	$ 141,486,000	$ 133,493,000
July 2016 [Member] \| Bickford Note Investment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Note Receivable Interest Rate	9.00%
Loan Term	5 years
Loans and Leases Receivable, Commitments, Fixed Rates	$ 14,000,000
Loans and Leases Receivable, Net Amount	$ 11,096,000
January 2017 [Member] \| Bickford Note Investment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Note Receivable Interest Rate	9.00%
Loan Term	5 years
Loans and Leases Receivable, Commitments, Fixed Rates	$ 14,000,000
Loans and Leases Receivable, Net Amount	$ 4,462,000

The concept represents a total loan term in number of years

No definition available.

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Namespace Prefix:	nhi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

This concept reflects the interest rate to be received on a loan receivable.

+ References

No definition available.

+ Details

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

- 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

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

- Definition

Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at stated interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=75032840&loc=d3e61044-112788

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=75032840&loc=d3e61082-112788

+ Details

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

- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Details

Name:	us-gaap_InvestmentTypeAxis=nhi_July2016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_InvestmentTypeAxis=nhi_January2017Member
Namespace Prefix:
Data Type:	na
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Period Type: