Organization and Summary of Significant Accounting Policies (Computation of Basic and Diluted Earnings Per Share) (Details) - USD ($)	1 Months Ended	12 Months Ended
	Oct. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Basic and Diluted Earnings:
Net earnings attributable to NNN		$ 392,340,000	$ 334,626,000	$ 290,113,000
Less: Excess of redemption value over carrying value of preferred shares redeemed		0	0	(10,897,000)
Net earnings attributable to common stockholders		392,340,000	334,626,000	264,217,000
Less: Earnings allocated to unvested restricted shares		(609,000)	(514,000)	(689,000)
Net Income (Loss) Available to Common Stockholders, Diluted, Total		$ 391,731,000	$ 334,112,000	$ 263,528,000
Basic and Diluted Weighted Average Shares Outstanding:
Weighted average number of shares outstanding (in shares)		182,184,038	177,332,094	175,554,961
Less: Unvested restricted shares (in shares)		(273,077)	(237,918)	(328,070)
Less: Unvested contingent restricted shares (in shares)		(710,921)	(690,520)	(515,970)
Weighted Average Number of Shares Outstanding, Basic, Total		181,200,040	176,403,656	174,710,921
Other dilutive securities (shares)		489,683	664,209	107,978
Weighted average number of shares outstanding used in diluted earnings per share (in shares)		181,689,723	177,067,865	174,818,899
Series F Preferred Stock
Basic and Diluted Earnings:
Less: preferred stock dividends		$ 0	$ 0	$ (14,999,000)
Less: Excess of redemption value over carrying value of preferred shares redeemed	$ (10,897,000)