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								12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Net earnings attributable to NNN	$ 44,241	$ 40,663	$ 44,352	$ 37,486	$ 34,066	$ 38,015	$ 33,505	$ 29,832	$ 160,145		$ 142,015		$ 92,325
Less: Excess of redemption value over carrying value of Series C preferred shares redeemed									0		(3,098)		0
Net earnings attributable to common stockholders									132,222		121,489		85,540
Less: Earnings attributable to unvested restricted shares									(503)		(741)		(622)
Net earnings used in basic and diluted earnings per share									131,719		120,748		84,918
Weighted average number of shares outstanding									118,969,771		107,873,577		88,972,723
Less: Unvested restricted shares									(448,590)		(654,127)		(630,102)
Less: Unvested contingent shares									(317,033)		(254,294)		(242,545)
Weighted average number of shares outstanding used in basic earnings per share									118,204,148		106,965,156		88,100,076
Convertible debt (in shares)									1,468,559		1,987,842		512,024
Other (in shares)									192,117		164,517		224,957
Weighted average number of shares outstanding used in diluted earnings per share									119,864,824		109,117,515		88,837,057
Series C Depositary Share
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Less: Preferred stock dividends									0	[1]	(1,979)	[1]	(6,785)	[1]
Series D Depositary Share
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Less: Preferred stock dividends									(19,047)	[2]	(15,449)	[2]	0	[2]
Series E Depositary Share
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Less: Preferred stock dividends									$ (8,876)	[3]	$ 0	[3]	$ 0	[3]

[1] The Series C Preferred Stock was redeemed in March 2012. The dividends paid during the quarter ended March 31, 2012 include accumulated and unpaid dividends through the redemption date.

[2] The Series D Preferred Stock dividends paid during the quarter ended June 30, 2012 include accumulated and unpaid dividends from the issuance date through the declaration date. The Series D Preferred Stock has no maturity date and will remain outstanding unless redeemed.

[3] 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.