Organization and Summary of Significant Accounting Policies (Computation of Basic and Diluted Earnings per Share) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Basic and Diluted Earnings:
Net earnings attributable to NNN		$ 50,784	$ 55,198	$ 173,409	$ 155,365
Net earnings attributable to common stockholders		41,925	46,339	146,833	128,789
Less: Earnings allocated to unvested restricted shares		(184)	(183)	(510)	(523)
Net earnings used in basic and diluted earnings per share		$ 41,741	$ 46,156	$ 146,323	$ 128,266
Basic and Diluted Weighted Average Shares Outstanding:
Weighted average number of shares outstanding (in shares)		146,982,759	134,789,572	144,301,606	133,810,946
Less: Unvested restricted stock (in shares)		(406,170)	(420,417)	(385,267)	(409,839)
Less: Unvested contingent shares (in shares)		(465,548)	(476,250)	(441,675)	(451,129)
Weighted average number of shares outstanding used in basic earnings per share (in shares)		146,111,041	133,892,905	143,474,664	132,949,978
Other dilutive securities (in shares)		570,551	353,193	561,501	356,290
Weighted average number of shares outstanding used in diluted earnings per share (in shares)		146,681,592	134,246,098	144,036,165	133,306,268
Series D Preferred Stock
Basic and Diluted Earnings:
Less: preferred stock dividends	[1]	$ (4,762)	$ (4,762)	$ (14,285)	$ (14,285)
Series E Preferred Stock
Basic and Diluted Earnings:
Less: preferred stock dividends	[1]	$ (4,097)	$ (4,097)	$ (12,291)	$ (12,291)

[1] The Series D and E preferred stock have no maturity date and will remain outstanding unless redeemed by NNN. The earliest redemption date for the Series D and Series E preferred stock is February 2017 and May 2018, respectively.