Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Earnings including noncontrolling interests	$ 141,937	$ 92,416	$ 73,353
Adjustments to reconcile net earnings to net cash provided by operating activities:
Performance incentive plan expense	10,136	8,283	5,756
Stock options expense – tax effect	0	0	122
Depreciation and amortization	75,334	58,817	49,084
Impairment losses and other charges	10,114	2,115	7,458
Impairment – commercial mortgage residual interests valuation	2,812	1,024	3,995
Amortization of notes payable discount	4,976	6,191	6,360
Amortization of debt costs	2,584	0	0
Amortization of mortgages payable premium	(29)	0	0
Amortization of deferred interest rate hedges	231	9	(166)
Equity in earnings of unconsolidated affiliate	(4,074)	(474)	(428)
Distributions received from unconsolidated affiliate	7,019	593	578
Gain on disposition of real estate	(10,956)	(721)	(2,075)
Deferred income taxes	732	884	(2,544)
Income tax valuation allowance	7,671	0	(3,121)
Change in operating assets and liabilities, net of assets acquired and liabilities assumed in business combinations:
Additions to held for sale real estate	(6,616)	(1,025)	(478)
Proceeds from disposition of held for sale real estate	0	1,993	42,817
Decrease in real estate leased to others using the direct financing method	1,624	1,595	1,544
Increase in work in process	(1,561)	(1,213)	(755)
Increase in mortgages, notes and accrued interest receivable	(187)	(96)	(467)
Decrease (increase) in receivables	(264)	1,108	(219)
Decrease (increase) in commercial mortgage residual interests	523	(654)	1,516
Decrease (increase) in accrued rental income	(456)	253	124
Decrease (increase) in other assets	1,657	746	(53)
Increase (decrease) in accrued interest payable	2,419	7,766	(129)
Increase (decrease) in other liabilities	(2,002)	2,682	(431)
Increase (decrease) in current tax liability	(152)	654	(169)
Net cash provided by operating activities	228,130	182,946	187,914
Cash flows from investing activities:
Proceeds from the disposition of real estate	81,402	10,696	10,312
Additions to real estate:
Accounted for using the operating method	(684,925)	(756,633)	(230,928)
Accounted for using the direct financing method	0	(1,747)	0
Increase in mortgages and notes receivable	(8,768)	(9,838)	(8,564)
Principal payments on mortgages and notes receivable	12,804	6,837	13,818
Payment of lease costs	(2,594)	(1,589)	(1,324)
Return of investment from unconsolidated affiliate	1,220	0	0
Other	(898)	206	(3,574)
Net cash used in investing activities	(601,759)	(752,068)	(220,260)
Cash flows from financing activities:
Proceeds from line of credit payable	1,184,900	805,300	278,900
Repayment of line of credit payable	(1,076,300)	(900,700)	(117,900)
Payment of interest rate hedge	0	(5,218)	0
Repayment of mortgages payable	(19,390)	(1,098)	(6,453)
Proceeds from notes payable	320,011	295,731	0
Repayment of notes payable	(50,000)	0	(20,000)
Repayment of notes payable - convertible	(164,649)	0	0
Payment of debt costs	(4,512)	(5,582)	(75)
Proceeds from issuance of common stock	185,223	540,560	17,692
Proceeds from issuance of preferred stock	287,500	0	0
Redemption of preferred stock	(92,000)	0	0
Payment of common stock dividends	(167,495)	(133,720)	(125,391)
Noncontrolling interest distributions	0	(45)	(861)
Noncontrolling interest contributions	0	41	43
Stock issuance costs	(12,237)	(19,328)	(1)
Net cash provided by financing activities	373,623	569,156	19,169
Net increase (decrease) in cash and cash equivalents	(6)	34	(13,177)
Cash and cash equivalents at beginning of year	2,082	2,048	15,225
Cash and cash equivalents at end of year	2,076	2,082	2,048
Supplemental disclosure of cash flow information:
Interest paid, net of amount capitalized	75,283	63,474	62,386
Taxes paid (received)	201	(561)	472
Supplemental disclosure of noncash investing and financing activities:
Issued 398,578, 141,351 and 392,474 shares of restricted and unrestricted common stock in 2012, 2011 and 2010, respectively, pursuant to NNN’s performance incentive plan	8,638	3,456	6,889
Issued 16,078, 9,632 and 10,092 shares of common stock in 2012, 2011 and 2010, respectively, to directors pursuant to NNN’s performance incentive plan	463	250	236
Issued 19,212, 26,023 and 25,066 shares of common stock in 2012, 2011 and 2010, respectively, pursuant to NNN’s Deferred Director Fee Plan	298	449	401
Surrender of 15,286 and 5,215 shares of restricted common stock in 2012 and 2011, respectively	357	109	0
Change in other comprehensive income	1,448	(5,491)	1,150
Change in lease classification (direct financing lease to operating lease)	1,678	3,407	0
Note and mortgage receivable accepted in connection with real estate transactions	0	0	5,950
Mortgages payable assumed in connection with real estate transactions	6,634	0	5,432
Real estate acquired in connection with mortgage receivable foreclosure	490	0	6,250
Real estate received in note receivable foreclosure	1,595	0	0
Series C Preferred Stock [Member]
Cash flows from financing activities:
Payment of preferred stock dividends	(1,979)	(6,785)	(6,785)
Series D Preferred Stock [Member]
Cash flows from financing activities:
Payment of preferred stock dividends	$ (15,449)	$ 0	$ 0