Major Customer - NHC (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2011 properties	Dec. 31, 2010 properties	Dec. 31, 2009
Number of Real Estate Properties	97	88
Rental income	$ 76,050	$ 71,289	$ 53,648
Common Stock Shares Held by NHC	1,630,462
National HealthCare Corporation [Member]
Number of Real Estate Properties	41
Rental income	35,996	35,212	34,782
Percent of rental income recognized from tenants	47.00%	49.00%	65.00%
Number of additional lease renewal options	3
Term of the lease renewal option period in years	5
Lease Extension Period in Years	15
Base rent revenue	33,700
Percentage Rent Rate	4
Skilled Nursing Facility [Member]
Number of Real Estate Properties	55	51
Skilled Nursing Facility [Member] \| National HealthCare Corporation [Member]
Number of Real Estate Properties	38
Independent Living Facility [Member]
Number of Real Estate Properties	4	4
Independent Living Facility [Member] \| National HealthCare Corporation [Member]
Number of Real Estate Properties	3
Subleased Facilities [Member] \| Skilled Nursing Facility [Member] \| National HealthCare Corporation [Member]
Number of Real Estate Properties	4
W. Andrew Adams [Member]
Officers' Compensation	$ 144	$ 1,071	$ 722

This element represents the number of entity shares held by NHC.

No definition available.

Name:	nhi_CommonStockSharesHeldByNhc
Namespace Prefix:	nhi_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the number of years involved in a lease extension period.

+ References

No definition available.

+ Details

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

- Definition

Lease renewal period in years

+ References

No definition available.

+ Details

Name:	nhi_LeaseRenewalPeriodInYears
Namespace Prefix:	nhi_
Data Type:	xbrli:integerItemType
Balance Type:	na
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

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 percent of NHI's total rental income recognized from tenants.

+ References

No definition available.

+ Details

Name:	nhi_PercentOfRentalIncomeRecognizedFromTenants
Namespace Prefix:	nhi_
Data Type:	num:percentItemType
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

Expenditures for salaries of officers. Does not include allocated share-based compensation, pension and post-retirement benefit expense or other labor-related non-salary expense. For commercial and industrial companies, excludes any direct and overhead labor that is included in cost of goods sold.

+ 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 210.5-03.4)

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

+ Details

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

- 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 Statement of Financial Accounting Standard (FAS)

-Number 13

-Paragraph 19

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: 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=6453417&loc=d3e39896-112707

+ Details

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

- Definition

The total amount of lease revenue recognized for the period for which the lessee was obligated under leasing arrangements regardless of any other events or conditions. This amount excludes contingent revenue and sublease revenue.

+ References

+ Details

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