Commitments And Contingencies Commitments and Contingencies (Schedule of Loan Commitments) (Details) - USD ($)	9 Months Ended
Sep. 30, 2018	Dec. 31, 2017
Loans and Leases Receivable, Commitments, Fixed Rates	$ 131,700,000
Loans and Leases Receivable, Net Amount	(155,461,000)	$ (141,486,000)
Notes Receivable Funding Commitment	45,423,000
Life Care Services [Member]
Loans and Leases Receivable, Commitments, Fixed Rates	60,000,000
Loans and Leases Receivable, Net Amount	(57,536,000)
Notes Receivable Funding Commitment	2,464,000
Bickford Senior Living [Member]
Loans and Leases Receivable, Commitments, Fixed Rates	56,700,000
Loans and Leases Receivable, Net Amount	(27,744,000)
Notes Receivable Funding Commitment	28,956,000
Senior Living Communities [Member]
Loans and Leases Receivable, Commitments, Fixed Rates	14,000,000
Revolving Credit Facility [Member] \| Senior Living Communities [Member]
Loans and Leases Receivable, Commitments, Fixed Rates	15,000,000
Loans and Leases Receivable, Net Amount	(997,000)
Notes Receivable Funding Commitment	14,003,000
Notes Receivable Remain Unfunded [Member]
Loans and Leases Receivable, Net Amount	$ (86,277,000)

This item represents the remaining funding commitment for a currently outstanding note receivable.

No definition available.

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

- 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

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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

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- Details

Name:	us-gaap_MajorCustomersAxis=nhi_BickfordSeniorLivingMember
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- Details

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- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_RevolvingCreditFacilityMember
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- Details

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