Organization and Summary of Significant Accounting Policies (Computation of Basic and Diluted Earnings per Share) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Basic and Diluted Earnings:
Net earnings attributable to NNN		$ 73,657	$ 70,683
Net earnings attributable to common stockholders		51,622	61,824
Less: Earnings allocated to unvested restricted shares		(130)	(151)
Net earnings used in basic and diluted earnings per share		$ 51,492	$ 61,673
Basic and Diluted Weighted Average Shares Outstanding:
Weighted average number of shares outstanding (in shares)		147,581,522	141,577,504
Less: Unvested restricted stock (in shares)		(285,887)	(343,466)
Less: Unvested contingent restricted shares (in shares)		(365,957)	(393,667)
Weighted average number of shares outstanding used in basic earnings per share (in shares)		146,929,678	140,840,371
Other dilutive securities (in shares)		349,859	485,632
Weighted average number of shares outstanding used in diluted earnings per share (in shares)		147,279,537	141,326,003
Series D Preferred Stock
Basic and Diluted Earnings:
Less: preferred stock dividends	[1]	$ (3,598)	$ (4,762)
Less: Excess of redemption value over carrying value of Series D preferred shares redeemed		(9,855)	0
Series E Preferred Stock
Basic and Diluted Earnings:
Less: preferred stock dividends	[2]	(4,097)	(4,097)
Series F Preferred Stock
Basic and Diluted Earnings:
Less: preferred stock dividends		$ (4,485)	$ 0

[1] The Series D preferred stock was redeemed in February 2017. The dividends paid during the quarter ended March 31, 2017 included accumulated and unpaid dividends through the redemption date.

[2] The Series E preferred stock has no maturity date and will remain outstanding unless redeemed by NNN. The earliest redemption date for the Series E Preferred Stock is May 2018.