Schedule IV - Mortgage Loans on Real Estate (Summary Schedule) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate	$ 68,214	$ 78,672	$ 75,465	$ 94,588
Mortgage Loans on Real Estate, New Mortgage Loans	0	6,566	12,422
Mortgage Loans on Real Estate, Other Additions	0	1,082	298
Mortgage Loans On Real Estate Total Additions	0	7,648	12,720
Settlement of mortgage note by real estate acquisition	0	0	22,936
Mortgage Loans On Real Estate, Impairment	2,300	0	0
Mortgage Loans on Real Estate, Collections of Principal	8,158	4,441	8,907
Mortgage Loans On Real Estate, Total Deductions	$ 10,458	$ 4,441	$ 31,843

This element represents the total amount of other than temporary impairment charges taken during the current period.

No definition available.

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

- Definition

This element represents the total amount of additions to mortgage loans during the reporting period.

+ References

No definition available.

+ Details

Name:	nhi_MortgageLoansOnRealEstateTotalAdditions
Namespace Prefix:	nhi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The total amount of reductions in principal on mortgage loans.

+ References

No definition available.

+ Details

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

- Definition

Settlement Of Mortgage Note By Real Estate Acquisition

+ References

No definition available.

+ Details

Name:	nhi_SettlementOfMortgageNoteByRealEstateAcquisition
Namespace Prefix:	nhi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Total carrying amount of mortgage loans as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 310

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-29.6)

-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule IV)

-URI http://asc.fasb.org/extlink&oid=6882300&loc=d3e5864-122674

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 29

-Article 12

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule IV

-Article 5

+ Details

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

- Details

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

- Definition

The amount of principal collected on mortgage loans on real estate during the reporting period.

+ References

+ Details

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

- Definition

Total amount of new mortgage loans on real estate during the reporting period.

+ References

+ Details

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

- Definition

Total amount of additions to mortgage loans other than new loans during the reporting period.

+ References

+ Details

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