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, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Net earnings attributable to NNN	$ 88,421	$ 82,933	$ 243,964	$ 212,543
Less: Series F preferred stock dividends	0	(4,485)	0	(13,455)
Net earnings attributable to common stockholders	88,421	78,448	243,964	199,088
Less: Earnings allocated to unvested restricted shares	(135)	(180)	(471)	(509)
Net earnings used in basic and diluted earnings per share	$ 88,286	$ 78,268	$ 243,493	$ 198,579
Basic and Diluted Weighted Average Shares Outstanding:
Weighted average number of shares outstanding	177,881,613	175,607,905	176,510,417	175,530,702
Less: Unvested restricted shares (in shares)	(246,116)	(340,725)	(292,433)	(323,808)
Less: Unvested contingent restricted shares (in shares)	(734,711)	(637,738)	(675,628)	(596,868)
Weighted Average Number of Shares Outstanding, Basic, Total	176,900,786	174,629,442	175,542,356	174,610,026
Other dilutive securities (in shares)	466,924	109,461	451,551	106,027
Weighted average number of shares outstanding used in diluted earnings per share (in shares)	177,367,710	174,738,903	175,993,907	174,716,053