Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
ASSETS
Accounted for using the operating method, net of accumulated depreciation and amortization	$ 3,565,782	$ 3,211,022
Accounted for using the direct financing method	24,539	26,518
Real estate, held for sale	53,361	50,202
Investment in unconsolidated affiliate	0	4,358
Mortgages, notes and accrued interest receivable, net of allowance	29,682	33,428
Commercial mortgage residual interests	12,508	15,299
Cash and cash equivalents	141,446	2,082
Receivables, net of allowance of $1,057 and $1,403, respectively	1,220	2,149
Accrued rental income, net of allowance of $3,086 and $4,870, respectively	25,806	25,187
Debt costs, net of accumulated amortization of $17,887 and $15,381, respectively	11,318	10,832
Other assets	68,536	53,352
Total assets	3,934,198	3,434,429
LIABILITIES AND EQUITY
Line of credit payable	0	65,600
Mortgages payable, including unamortized premium of $202 and $0, respectively	10,873	23,171
Notes payable – convertible, net of unamortized discount of $3,174 and $6,363, respectively	358,561	355,371
Notes payable, net of unamortized discount of $9,571 and $5,033, respectively	1,165,429	894,967
Accrued interest payable	22,112	15,108
Other liabilities	99,145	76,336
Total liabilities	1,656,120	1,430,553
Stockholders' equity:
Common stock, $0.01 par value. Authorized 375,000,000 shares; 109,421,774 and 104,754,859 shares issued and outstanding, respectively	1,096	1,049
Excess stock, $0.01 par value. Authorized 390,000,000 shares; none issued or outstanding	0	0
Capital in excess of par value	2,075,112	1,958,225
Retained earnings (loss)	(83,497)	(44,946)
Accumulated other comprehensive income (loss)	(3,448)	(3,830)
Total stockholders' equity of NNN	2,276,763	2,002,498
Noncontrolling interests	1,315	1,378
Total equity	2,278,078	2,003,876
Total liabilities and equity	3,934,198	3,434,429
Series D Depositary Share [Member]
Stockholders' equity:
Series D, 11,500,000 depositary shares issued and outstanding, at stated liquidation value of $25 per share	287,500	0
Series C, 3,680,000 depositary shares issued and outstanding, at stated liquidation value of $25 per share	287,500	0
Series C Depositary Share [Member]
Stockholders' equity:
Series D, 11,500,000 depositary shares issued and outstanding, at stated liquidation value of $25 per share	0	92,000
Series C, 3,680,000 depositary shares issued and outstanding, at stated liquidation value of $25 per share	$ 0	$ 92,000