Significant Accounting Policies	9 Months Ended
Sep. 30, 2013
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES We, the management of National Health Investors, Inc., ("NHI" or the "Company") believe that the unaudited condensed consolidated financial statements of which these notes are an integral part include all normal, recurring adjustments which are necessary to fairly present the condensed consolidated financial position, results of operations and cash flows of NHI in all material respects. The Condensed Consolidated Balance Sheet at December 31, 2012 has been derived from the audited consolidated financial statements at that date. We assume that users of these condensed consolidated financial statements have read or have access to the audited December 31, 2012 consolidated financial statements and Management's Discussion and Analysis of Financial Condition and Results of Operations and that the adequacy of additional disclosure needed for a fair presentation, except in regard to material contingencies, may be determined in that context. Accordingly, footnotes and other disclosures which would substantially duplicate those contained in our most recent Annual Report on Form 10-K for the year ended December 31, 2012 have been omitted. This condensed consolidated financial information is not necessarily indicative of the results that may be expected for a full year for a variety of reasons including, but not limited to, acquisitions and dispositions, changes in interest rates, rents and the timing of debt and equity financings. For a better understanding of NHI and its condensed consolidated financial statements, we recommend reading these condensed consolidated financial statements in conjunction with the audited consolidated financial statements for the year ended December 31, 2012, which are included in our 2012 Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission, a copy of which is available at our web site: www.nhireit.com. Principles of Consolidation - The accompanying condensed consolidated financial statements include our accounts and the accounts of our wholly-owned subsidiaries and the joint venture entity over which we exercise control. All inter-company transactions and balances have been eliminated in consolidation. Net income is reduced by the portion of net income attributable to noncontrolling interests. We apply Financial Accounting Standards Board ("FASB") guidance for our arrangements with variable interest entities ("VIEs") which requires us to identify entities for which control is achieved through means other than voting rights and to determine which business enterprise is the primary beneficiary of the VIE. A VIE is broadly defined as an entity with one or more of the following characteristics: (a) the total equity investment at risk is insufficient to finance the entity's activities without additional subordinated financial support; (b) as a group, the holders of the equity investment at risk lack (i) the ability to make decisions about the entity's activities through voting or similar rights, (ii) the obligation to absorb the expected losses of the entity, or (iii) the right to receive the expected residual returns of the entity; or (c) the equity investors have voting rights that are not proportional to their economic interests, and substantially all of the entity's activities either involve, or are conducted on behalf of, an investor that has disproportionately few voting rights. We consolidate investments in VIEs when we are determined to be the primary beneficiary of the VIE. We may change our original assessment of a VIE due to events such as modifications of contractual arrangements that affect the characteristics or adequacy of the entity's equity investments at risk and the disposal of all or a portion of an interest held by the primary beneficiary. We identify the primary beneficiary of a VIE as the enterprise that has both: (i) the power to direct the activities of the VIE that most significantly impact the entity's economic performance; and (ii) the obligation to absorb losses or the right to receive benefits of the VIE that could be significant to the entity. We perform this analysis on an ongoing basis. At September 30, 2013, we held an interest in one unconsolidated VIE, of which we were not the primary beneficiary. We also apply FASB guidance related to investments in joint ventures based on the type of controlling rights held by the members' interests in limited liability companies that may preclude consolidation by the majority equity owner in certain circumstances in which the majority equity owner would otherwise consolidate the joint venture. We structure our joint ventures to be compliant with the provisions of the REIT Investment Diversification and Empowerment Act of 2007 ("RIDEA") which permits NHI to receive rent payments through a triple-net lease between a property company and an operating company, and is designed to give NHI the opportunity to capture additional value on the improving performance of the operating company through distributions to a taxable REIT subsidiary ("TRS"). Accordingly, the TRS holds our equity interest in an unconsolidated operating company, which we do not control, and provides an organizational structure that will allow the TRS to engage in a broad range of activities and share in revenues that would otherwise be non-qualifying income under the REIT gross income tests. Equity-Method Investment - We report our TRS investment in an unconsolidated entity, over whose operating and financial policies we have the ability to exercise significant influence but not control, under the equity method of accounting. Under this method of accounting, our pro rata share of the entity's earnings or losses is included in our Condensed Consolidated Statements of Income. Additionally, we adjust our investment carrying amount to reflect our share of changes in an equity-method investee's capital resulting from its capital transactions. The initial carrying value of our equity-method investments is based on the fair value of the net assets of the entity at the time we acquired our interest. We estimate fair values of the net assets of our equity-method investees based on discounted cash flow models. The inputs we use in these models are based on assumptions that we believe to be within a reasonable range of current market rates for the respective investments. We evaluate our equity-method investments for impairment whenever events or changes in circumstances indicate that the carrying value of our investment may exceed the fair value. If it is determined that a decline in the fair value of our investment is not temporary, and if such reduced fair value is below its carrying value, an impairment is recorded. The determination of the fair value of our equity-method investments involve significant judgment. Our estimates consider all available evidence including the present value of the expected future cash flows discounted at market rates, general economic conditions and other relevant factors. Noncontrolling Interests - We present the portion of any equity that we do not own in entities that we control (and thus consolidate) as noncontrolling interests and classify such interests as a component of consolidated equity, separate from total NHI stockholders' equity, in our Condensed Consolidated Balance Sheets. In addition, we include net income attributable to the noncontrolling interests in net income in our Condensed Consolidated Statements of Income. Use of Estimates - The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Fair Value Measurements - Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. A three-level fair value hierarchy is required to prioritize the inputs used to measure fair value. This hierarchy requires entities to maximize the use of observable inputs and minimize the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: Level 1 - Quoted prices in active markets for identical assets or liabilities. Level 2 - Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data. Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. This includes certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs. If the fair value measurement is based on inputs from different levels of the hierarchy, the level within which the entire fair value measurement falls is the lowest level input that is significant to the fair value measurement in its entirety. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. When an event or circumstance alters our assessment of the observability and thus the appropriate classification of an input to a fair value measurement which we deem to be significant to the fair value measurement as a whole, we will transfer that fair value measurement to the appropriate level within the fair value hierarchy. Real Estate Properties - Real estate properties are recorded at cost or, if acquired through business combination, at fair value. Cost or fair value at the time of acquisition is allocated among land, buildings, tenant improvements, lease and other intangibles, and personal property. For properties acquired in transactions accounted for as asset purchases, the purchase price allocation is based on the relative fair values of the assets acquired. Cost includes capitalized interest during construction periods. We use the straight-line method of depreciation for buildings over their estimated useful lives of 40 years, and improvements over their estimated useful lives ranging from 3 to 25 years. We evaluate the recoverability of the carrying value of our real estate properties on a property-by-property basis. On a quarterly basis, we review our properties for recoverability when events or circumstances, including significant physical changes in the property, significant adverse changes in general economic conditions and significant deteriorations of the underlying cash flows of the property, indicate that the carrying amount of the property may not be recoverable. The need to recognize an impairment charge is based on estimated undiscounted future cash flows from a property compared to the carrying value of that property. If recognition of an impairment charge is necessary, it is measured as the amount by which the carrying amount of the property exceeds the fair value of the property. We have reclassified for all periods presented the operations of facilities meeting the accounting criteria as either being sold or held for sale as discontinued operations in the Condensed Consolidated Statements of Income. Long-lived assets classified as held for sale are reported separately in the Condensed Consolidated Balance Sheets. When assets previously classified as being held for sale no longer meet the accounting criteria for such classification, we reclassify those assets as held and used, measured at the lower of their carrying amount before the assets were classified as held for sale (adjusted in the period in which the decision not to sell was made for any depreciation expense that would have been recognized had the assets been continuously classified as held and used) or their fair value at the date of the subsequent decision not to sell. Results of operations of the facilities previously disclosed in our Condensed Consolidated Statements of Income as discontinued operations which no longer meet the accounting criteria as held for sale are reclassified into continuing operations for all periods presented. There is no change to reported net income for the prior periods as a result of this reclassification. Mortgage and Other Notes Receivable - Each quarter, we evaluate the carrying values of our notes receivable on an instrument-by-instrument basis for recoverability when events or circumstances, including the non-receipt of contractual principal and interest payments, significant deteriorations of the financial condition of the borrower and significant adverse changes in general economic conditions, indicate that the carrying amount of the note receivable may not be recoverable. If a note receivable becomes more than 30 days delinquent as to contractual principal or interest payments, the loan is classified as non-performing, and thereafter we recognize all amounts due when received. If necessary, an impairment is measured as the amount by which the carrying amount exceeds the discounted cash flows expected to be received under the note receivable or, if foreclosure is probable, the fair value of the collateral securing the note receivable. New Accounting Pronouncements - In February 2013, the FASB issued ASU 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income, which amends FASB Topic 220, Comprehensive Income, which requires entities to provide information about amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the income statement or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income. ASU 2013-02 was effective prospectively for reporting periods beginning after December 15, 2012. The adoption of ASU 2013-02 did not have a material impact on our condensed consolidated financial statements. In July 2013 the FASB issued ASU 2013-10, Derivatives and Hedging, which amends Topic 815. ASU 2013-10 permits the Fed Funds Effective Swap Rate (OIS) to be used as a U.S. benchmark interest rate for hedge accounting purposes under Topic 815, in addition to U.S. Treasury and LIBOR. ASU 2013-10 also removes the restriction on using different benchmark rates for similar hedges. ASU 2013-10 is effective prospectively for qualifying new or redesignated hedging relationships entered into on or after July 17, 2013. The adoption of ASU 2013-10 did not have a material impact on our financial statements.

SIGNIFICANT ACCOUNTING POLICIES

We, the management of National Health Investors, Inc., ("NHI" or the "Company") believe that the unaudited condensed consolidated financial statements of which these notes are an integral part include all normal, recurring adjustments which are necessary to fairly present the condensed consolidated financial position, results of operations and cash flows of NHI in all material respects. The Condensed Consolidated Balance Sheet at December 31, 2012 has been derived from the audited consolidated financial statements at that date. We assume that users of these condensed consolidated financial statements have read or have access to the audited December 31, 2012 consolidated financial statements and Management's Discussion and Analysis of Financial Condition and Results of Operations and that the adequacy of additional disclosure needed for a fair presentation, except in regard to material contingencies, may be determined in that context. Accordingly, footnotes and other disclosures which would substantially duplicate those contained in our most recent Annual Report on Form 10-K for the year ended December 31, 2012 have been omitted. This condensed consolidated financial information is not necessarily indicative of the results that may be expected for a full year for a variety of reasons including, but not limited to, acquisitions and dispositions, changes in interest rates, rents and the timing of debt and equity financings. For a better understanding of NHI and its condensed consolidated financial statements, we recommend reading these condensed consolidated financial statements in conjunction with the audited consolidated financial statements for the year ended December 31, 2012, which are included in our 2012 Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission, a copy of which is available at our web site: www.nhireit.com.

Principles of Consolidation - The accompanying condensed consolidated financial statements include our accounts and the accounts of our wholly-owned subsidiaries and the joint venture entity over which we exercise control. All inter-company transactions and balances have been eliminated in consolidation. Net income is reduced by the portion of net income attributable to noncontrolling interests.

We apply Financial Accounting Standards Board ("FASB") guidance for our arrangements with variable interest entities ("VIEs") which requires us to identify entities for which control is achieved through means other than voting rights and to determine which business enterprise is the primary beneficiary of the VIE. A VIE is broadly defined as an entity with one or more of the following characteristics: (a) the total equity investment at risk is insufficient to finance the entity's activities without additional subordinated financial support; (b) as a group, the holders of the equity investment at risk lack (i) the ability to make decisions about the entity's activities through voting or similar rights, (ii) the obligation to absorb the expected losses of the entity, or (iii) the right to receive the expected residual returns of the entity; or (c) the equity investors have voting rights that are not proportional to their economic interests, and substantially all of the entity's activities either involve, or are conducted on behalf of, an investor that has disproportionately few voting rights. We consolidate investments in VIEs when we are determined to be the primary beneficiary of the VIE. We may change our original assessment of a VIE due to events such as modifications of contractual arrangements that affect the characteristics or adequacy of the entity's equity investments at risk and the disposal of all or a portion of an interest held by the primary beneficiary.

We identify the primary beneficiary of a VIE as the enterprise that has both: (i) the power to direct the activities of the VIE that most significantly impact the entity's economic performance; and (ii) the obligation to absorb losses or the right to receive benefits of the VIE that could be significant to the entity. We perform this analysis on an ongoing basis. At September 30, 2013, we held an interest in one unconsolidated VIE, of which we were not the primary beneficiary.

We also apply FASB guidance related to investments in joint ventures based on the type of controlling rights held by the members' interests in limited liability companies that may preclude consolidation by the majority equity owner in certain circumstances in which the majority equity owner would otherwise consolidate the joint venture.

We structure our joint ventures to be compliant with the provisions of the REIT Investment Diversification and Empowerment Act of 2007 ("RIDEA") which permits NHI to receive rent payments through a triple-net lease between a property company and an operating company, and is designed to give NHI the opportunity to capture additional value on the improving performance of the operating company through distributions to a taxable REIT subsidiary ("TRS"). Accordingly, the TRS holds our equity interest in an unconsolidated operating company, which we do not control, and provides an organizational structure that will allow the TRS to engage in a broad range of activities and share in revenues that would otherwise be non-qualifying income under the REIT gross income tests.

Equity-Method Investment - We report our TRS investment in an unconsolidated entity, over whose operating and financial policies we have the ability to exercise significant influence but not control, under the equity method of accounting. Under this method of accounting, our pro rata share of the entity's earnings or losses is included in our Condensed Consolidated Statements of Income. Additionally, we adjust our investment carrying amount to reflect our share of changes in an equity-method investee's capital resulting from its capital transactions.

The initial carrying value of our equity-method investments is based on the fair value of the net assets of the entity at the time we acquired our interest. We estimate fair values of the net assets of our equity-method investees based on discounted cash flow models. The inputs we use in these models are based on assumptions that we believe to be within a reasonable range of current market rates for the respective investments.

We evaluate our equity-method investments for impairment whenever events or changes in circumstances indicate that the carrying value of our investment may exceed the fair value. If it is determined that a decline in the fair value of our investment is not temporary, and if such reduced fair value is below its carrying value, an impairment is recorded. The determination of the fair value of our equity-method investments involve significant judgment. Our estimates consider all available evidence including the present value of the expected future cash flows discounted at market rates, general economic conditions and other relevant factors.

Noncontrolling Interests - We present the portion of any equity that we do not own in entities that we control (and thus consolidate) as noncontrolling interests and classify such interests as a component of consolidated equity, separate from total NHI stockholders' equity, in our Condensed Consolidated Balance Sheets. In addition, we include net income attributable to the noncontrolling interests in net income in our Condensed Consolidated Statements of Income.

Use of Estimates - The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Fair Value Measurements - Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. A three-level fair value hierarchy is required to prioritize the inputs used to measure fair value. This hierarchy requires entities to maximize the use of observable inputs and minimize the use of unobservable inputs.

The three levels of inputs used to measure fair value are as follows:

Level 1 - Quoted prices in active markets for identical assets or liabilities.

Level 2 - Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data.

Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. This includes certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs.

If the fair value measurement is based on inputs from different levels of the hierarchy, the level within which the entire fair value measurement falls is the lowest level input that is significant to the fair value measurement in its entirety. Our assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. When an event or circumstance alters our assessment of the observability and thus the appropriate classification of an input to a fair value measurement which we deem to be significant to the fair value measurement as a whole, we will transfer that fair value measurement to the appropriate level within the fair value hierarchy.

Real Estate Properties - Real estate properties are recorded at cost or, if acquired through business combination, at fair value. Cost or fair value at the time of acquisition is allocated among land, buildings, tenant improvements, lease and other intangibles, and personal property. For properties acquired in transactions accounted for as asset purchases, the purchase price allocation is based on the relative fair values of the assets acquired. Cost includes capitalized interest during construction periods. We use the straight-line method of depreciation for buildings over their estimated useful lives of 40 years, and improvements over their estimated useful lives ranging from 3 to 25 years.

We evaluate the recoverability of the carrying value of our real estate properties on a property-by-property basis. On a quarterly basis, we review our properties for recoverability when events or circumstances, including significant physical changes in the property, significant adverse changes in general economic conditions and significant deteriorations of the underlying cash flows of the property, indicate that the carrying amount of the property may not be recoverable. The need to recognize an impairment charge is based on estimated undiscounted future cash flows from a property compared to the carrying value of that property. If recognition of an impairment charge is necessary, it is measured as the amount by which the carrying amount of the property exceeds the fair value of the property.

We have reclassified for all periods presented the operations of facilities meeting the accounting criteria as either being sold or held for sale as discontinued operations in the Condensed Consolidated Statements of Income. Long-lived assets classified as held for sale are reported separately in the Condensed Consolidated Balance Sheets. When assets previously classified as being held for sale no longer meet the accounting criteria for such classification, we reclassify those assets as held and used, measured at the lower of their carrying amount before the assets were classified as held for sale (adjusted in the period in which the decision not to sell was made for any depreciation expense that would have been recognized had the assets been continuously classified as held and used) or their fair value at the date of the subsequent decision not to sell. Results of operations of the facilities previously disclosed in our Condensed Consolidated Statements of Income as discontinued operations which no longer meet the accounting criteria as held for sale are reclassified into continuing operations for all periods presented. There is no change to reported net income for the prior periods as a result of this reclassification.

Mortgage and Other Notes Receivable - Each quarter, we evaluate the carrying values of our notes receivable on an instrument-by-instrument basis for recoverability when events or circumstances, including the non-receipt of contractual principal and interest payments, significant deteriorations of the financial condition of the borrower and significant adverse changes in general economic conditions, indicate that the carrying amount of the note receivable may not be recoverable. If a note receivable becomes more than 30 days delinquent as to contractual principal or interest payments, the loan is classified as non-performing, and thereafter we recognize all amounts due when received. If necessary, an impairment is measured as the amount by which the carrying amount exceeds the discounted cash flows expected to be received under the note receivable or, if foreclosure is probable, the fair value of the collateral securing the note receivable.

New Accounting Pronouncements - In February 2013, the FASB issued ASU 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income, which amends FASB Topic 220, Comprehensive Income, which requires entities to provide information about amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the income statement or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income. ASU 2013-02 was effective prospectively for reporting periods beginning after December 15, 2012. The adoption of ASU 2013-02 did not have a material impact on our condensed consolidated financial statements.

In July 2013 the FASB issued ASU 2013-10, Derivatives and Hedging, which amends Topic 815. ASU 2013-10 permits the Fed Funds Effective Swap Rate (OIS) to be used as a U.S. benchmark interest rate for hedge accounting purposes under Topic 815, in addition to U.S. Treasury and LIBOR. ASU 2013-10 also removes the restriction on using different benchmark rates for similar hedges. ASU 2013-10 is effective prospectively for qualifying new or redesignated hedging relationships entered into on or after July 17, 2013. The adoption of ASU 2013-10 did not have a material impact on our financial statements.