CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Series F Preferred Stock	Total  Stockholders’ Equity of NNN	Total  Stockholders’ Equity of NNN Series F Preferred Stock	Preferred Stock Series F Preferred Stock	Common Stock	Capital in Excess of Par Value	Accumulated Deficit	Accumulated Deficit Series F Preferred Stock	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Balances at Dec. 31, 2019	$ 4,331,682		$ 4,331,675		$ 345,000	$ 1,718	$ 4,495,314	$ (499,229)		$ (11,128)	$ 7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	111,441		111,443					111,443			(2)
Dividends declared and paid:
Preferred stock dividends declared and paid		$ (8,970)		$ (8,970)					$ (8,970)
Common stock dividends declared and paid	(175,267)		(175,267)				1,151	(176,418)
Issuance of common stock:
Director compensation	596		596				596
Stock purchase plan	170		170				170
ATM equity program	52,763		52,763			14	52,749
Restricted shares, net of forfeitures	0		0			3	(3)
Stock issuance costs	(746)		(746)				(746)
Amortization of deferred compensation	5,727		5,727				5,727
Amortization of interest rate hedges	1,021		1,021							1,021
Fair value of forward starting swaps	(7,617)		(7,617)							(7,617)
Balances at Jun. 30, 2020	4,310,800		4,310,795		345,000	1,735	4,554,958	(573,174)		(17,724)	5
Balances at Mar. 31, 2020	4,300,935		4,300,930		345,000	1,721	4,499,255	(526,684)		(18,362)	5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	46,265		46,265					46,265
Dividends declared and paid:
Preferred stock dividends declared and paid		(4,485)		(4,485)					(4,485)
Common stock dividends declared and paid	(87,739)		(87,739)				531	(88,270)
Issuance of common stock:
Director compensation	298		298				298
Stock purchase plan	94		94				94
ATM equity program	52,763		52,763			14	52,749
Stock issuance costs	(746)		(746)				(746)
Amortization of deferred compensation	2,777		2,777				2,777
Amortization of interest rate hedges	638		638							638
Fair value of forward starting swaps	0
Balances at Jun. 30, 2020	4,310,800		4,310,795		345,000	1,735	4,554,958	(573,174)		(17,724)	5
Balances at Dec. 31, 2020	4,319,304		4,319,300		345,000	1,753	4,633,771	(644,779)		(16,445)	4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	129,608		129,610					129,610			(2)
Dividends declared and paid:
Preferred stock dividends declared and paid		(8,970)		(8,970)					(8,970)
Common stock dividends declared and paid	(180,612)		(180,612)				1,207	(181,819)
Issuance of common stock:
Director compensation	534		534				534
Stock purchase plan	165		165				165
ATM equity program	1,234		1,234			1	1,233
Restricted shares, net of forfeitures	0		0			3	(3)
Stock issuance costs	(202)		(202)				(202)
Amortization of deferred compensation	7,888		7,888				7,888
Amortization of interest rate hedges	1,929		1,929							1,929
Fair value of forward starting swaps	0
Balances at Jun. 30, 2021	4,270,878		4,270,876		345,000	1,757	4,644,593	(705,958)		(14,516)	2
Balances at Mar. 31, 2021	4,287,839		4,287,835		345,000	1,757	4,639,680	(683,525)		(15,077)	4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	73,021		73,023					73,023			(2)
Dividends declared and paid:
Preferred stock dividends declared and paid		$ (4,485)		$ (4,485)					$ (4,485)
Common stock dividends declared and paid	(90,342)		(90,342)				629	(90,971)
Issuance of common stock:
Director compensation	267		267				267
Stock purchase plan	95		95				95
Stock issuance costs	(46)		(46)				(46)
Amortization of deferred compensation	3,968		3,968				3,968
Amortization of interest rate hedges	561		561							561
Fair value of forward starting swaps	0
Balances at Jun. 30, 2021	$ 4,270,878		$ 4,270,876		$ 345,000	$ 1,757	$ 4,644,593	$ (705,958)		$ (14,516)	$ 2