Consolidated Balance Sheets (USD $)	Mar. 31, 2013	Dec. 31, 2012
Assets
Land	$ 58,869,000	$ 58,869,000
Buildings and improvements	637,043,000	636,994,000
Construction in progress	4,922,000	2,673,000
Real estate properties, gross	700,834,000	698,536,000
Less accumulated depreciation	(167,549,000)	(163,146,000)
Real estate properties, net	533,285,000	535,390,000
Mortgage notes receivable, net	80,059,000	84,250,000
Investment in preferred stock, at cost	38,132,000	38,132,000
Cash and cash equivalents	6,050,000	9,172,000
Marketable securities	14,845,000	12,884,000
Straight-line rent receivable	13,652,000	12,370,000
Deferred costs and other assets	12,507,000	12,172,000
Assets held for sale, net	1,611,000	1,611,000
Total Assets	700,141,000	705,981,000
Liabilities and Equity
Debt	203,250,000	203,250,000
Real estate purchase liabilities	4,256,000	4,256,000
Accounts payable and accrued expenses	3,590,000	4,301,000
Dividends Payable	19,375,000	24,793,000
Deferred income	1,294,000	1,334,000
Total Liabilities	231,765,000	237,934,000
Commitments and Contingencies
National Health Investors Stockholders' Equity:
Common stock, $.01 par value; 40,000,000 shares authorized; 27,857,217 and 27,751,208 shares issued and outstanding, respectively	279,000	279,000
Capital in excess of par value	469,569,000	467,843,000
Cumulative dividends in excess of net income	(22,127,000)	(18,495,000)
Accumulated other comprehensive income	9,786,000	7,555,000
Total National Health Investors Stockholders' Equity	457,507,000	457,182,000
Noncontrolling interest	10,869,000	10,865,000
Total Equity	468,376,000	468,047,000
Total Liabilities and Equity	700,141,000	705,981,000
Noncontrolling Interest [Member]
National Health Investors Stockholders' Equity:
Total Equity	$ 10,869,000	$ 10,865,000