Organization And Summary Of Significant Accounting Policies (Computation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Net earnings attributable to NNN	$ 44,352	$ 38,015	$ 115,904		$ 101,353
Less: Excess of redemption value over carrying value of Series C preferred shares redeemed	0	0	0		(3,098)
Net earnings attributable to common stockholders	34,810	33,253	96,839		85,588
Less: Earnings attributable to unvested restricted shares	(135)	(215)	(366)		(525)
Net earnings used in basic earnings per share	34,675	33,038	96,473		85,063
Reallocated undistributed loss	0	(1)	(3)		(4)
Net earnings used in diluted earnings per share	34,675	33,037	96,470		85,059
Weighted average number of shares outstanding (in shares)	121,096,076	108,461,120	117,973,443		107,039,590
Less: Unvested restricted stock (in shares)	(469,370)	(696,270)	(441,588)		(652,890)
Less: Contingent shares (in shares)	(338,816)	(276,915)	(309,692)		(246,698)
Weighted average number of shares outstanding used in basic earnings per share (in shares)	120,287,890	107,487,935	117,222,163		106,140,002
Contingent shares (in shares)	0	0	0		8,459
Convertible notes payable (in shares)	768,843	2,692,153	1,963,457		1,787,275
Common stock options (in shares)	0	0	0		1,287
Directors' deferred fee plan (in shares)	173,499	159,617	170,574		154,886
Weighted average number of shares outstanding used in diluted earnings per share	121,230,232	110,339,705	119,356,194		108,091,909
Series C Depositary Share [Member]
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Less: Series C preferred stock dividends and Series D preferred stock dividends	0	0	0	[1]	(1,979)	[1]
Series D Depositary Share [Member]
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Less: Series C preferred stock dividends and Series D preferred stock dividends	(4,762)	(4,762)	(14,285)	[2]	(10,688)	[2]
Series E Depositary Share [Member]
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Less: Series C preferred stock dividends and Series D preferred stock dividends	$ (4,780)	$ 0	$ (4,780)	[2],[3]	$ 0	[2],[3]

[1] The Series C preferred stock was redeemed in March 2012. The dividends paid during the nine months ended September 30, 2012 include accumulated and unpaid dividends through the redemption date.

[2] The Series E preferred stock dividends paid during the quarter ended September 30, 2013 include accumulated and unpaid dividends from the issuance date through the declaration date.

[3] The Series D and E preferred stock have no maturity date and will remain outstanding unless redeemed.