CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues:
Rental income	$ 723,859,000	$ 658,793,000	$ 669,009,000
Interest and other income from real estate transactions	2,548,000	1,888,000	1,478,000
Total revenues	726,407,000	660,681,000	670,487,000
Operating expenses:
General and administrative	44,640,000	38,161,000	37,651,000
Real estate	28,385,000	28,362,000	27,656,000
Depreciation and amortization	205,220,000	196,623,000	188,871,000
Leasing transaction costs	203,000	76,000	261,000
Impairment losses - real estate, net of recoveries	21,957,000	37,442,000	31,992,000
Executive retirement costs	0	1,766,000	0
Total operating expenses	300,405,000	302,430,000	286,431,000
Gain on disposition of real estate	23,094,000	16,238,000	32,463,000
Earnings from operations	449,096,000	374,489,000	416,519,000
Other expenses (revenues):
Interest and other income	(216,000)	(417,000)	(3,112,000)
Interest expense	137,874,000	129,431,000	120,023,000
Loss on early extinguishment of debt	21,328,000	16,679,000	0
Total other expenses (revenues)	158,986,000	(145,693,000)	116,911,000
Net earnings	290,110,000	228,796,000	299,608,000
Loss (earnings) attributable to noncontrolling interests	3,000	3,000	(428,000)
Net earnings attributable to NNN	290,113,000	228,799,000	299,180,000
Excess of redemption value over carrying value of preferred shares redeemed	(10,897,000)	0	(9,856,000)
Net earnings attributable to common stockholders	$ 264,217,000	$ 210,859,000	$ 258,183,000
Net earnings per share of common stock:
Basic (in dollars per share)	$ 1.51	$ 1.22	$ 1.56
Diluted (in dollars per share)	$ 1.51	$ 1.22	$ 1.56
Weighted average number of common shares outstanding:
Basic (in shares)	174,710,921	172,109,713	164,688,498
Diluted (in shares)	174,818,899	172,217,077	165,083,679
Other comprehensive income:
Net earnings attributable to NNN	$ 290,113,000	$ 228,799,000	$ 299,180,000
Amortization of interest rate hedges	3,073,000	2,300,000	1,307,000
Fair value of forward starting swaps	(1,584,000)	(7,617,000)	(5,524,000)
Realized gain – available-for-sale securities	0	0	116,000
Realized gain – available-for-sale securities	0	0	(1,331,000)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest, Total	291,602,000	223,482,000	293,748,000
Comprehensive income attributable to non-controlling interests	(3,000)	(3,000)	428,000
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	291,599,000	223,479,000	294,176,000
Series E Preferred Stock
Other expenses (revenues):
Preferred stock dividends	0	0	(13,201,000)
Series F Preferred Stock
Other expenses (revenues):
Preferred stock dividends	$ (14,999,000)	$ (17,940,000)	$ (17,940,000)