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
	Mar. 31, 2013		Mar. 31, 2012
Earnings Per Share, Basic and Diluted, by Common Class, Including Two Class Method [Line Items]
Net earnings attributable to NNN	$ 34,066		$ 29,832
Less: Excess of redemption value over carrying value of preferred shares redeemed	0		(3,098)
Net earnings attributable to common stockholders	29,304		24,755
Less: Earnings attributable to unvested restricted shares	(102)		(566)
Net earnings used in basic earnings per share	29,202		24,189
Reallocated undistributed loss	0		0
Net earnings used in diluted earnings per share	29,202		24,189
Weighted average number of shares outstanding (in shares)	114,126,832		105,635,630
Less: Unvested restricted stock (in shares)	(385,258)		(568,163)
Less: Contingent shares (in shares)	(250,473)		(226,600)
Weighted average number of shares outstanding used in basic earnings per share (in shares)	113,491,101		104,840,867
Contingent shares (in shares)	0		25,471
Convertible notes payable (in shares)	2,191,512		1,192,706
Common stock options (in shares)	0		2,286
Directors' deferred fee plan (in shares)	167,640		150,036
Weighted average number of shares outstanding used in diluted earnings per share (in shares)	115,850,253		106,211,366
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	[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)	[2]	$ 0	[2]

[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 has no maturity date and will remain outstanding unless redeemed.