CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net earnings		$ 228,796	$ 299,608	$ 292,485
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization		196,623	188,871	174,398
Impairment losses – real estate, net of recoveries		37,442	31,992	28,211
Loss on early extinguishment of debt		16,679	0	18,240
Amortization of notes payable discount		3,036	1,739	3,263
Amortization of debt costs		5,009	3,731	4,611
Amortization of mortgages payable premium		(85)	(86)	(85)
Amortization of interest rate hedges		2,300	1,307	3,664
Settlement of forward starting swaps		(13,141)	0	4,080
Gain on disposition of real estate		(16,238)	(32,463)	(65,070)
Performance incentive plan expense		14,479	11,547	10,417
Performance incentive plan payment		(846)	(775)	(432)
Change in operating assets and liabilities, net of assets acquired and liabilities assumed:
Decrease in real estate leased to others using the direct financing method		210	602	874
Decrease (increase) in receivables		(1,464)	923	(203)
Increase in accrued rental income		(26,027)	(2,333)	(747)
Decrease (increase) in other assets		488	(96)	793
Increase (decrease) in accrued interest payable		1,151	(1,269)	(792)
Increase (decrease) in other liabilities		1,986	(1,379)	(1,516)
Other		(204)	(192)	(282)
Net cash provided by operating activities		450,194	501,727	471,909
Cash flows from investing activities:
Proceeds from the disposition of real estate		53,254	123,997	148,476
Additions to real estate:
Accounted for using the operating method		(195,944)	(747,521)	(756,971)
Principal payments received on mortgages and notes receivable		374	3,100	0
Other		(500)	1,016	(876)
Net cash used in investing activities		(142,816)	(619,408)	(609,371)
Cash flows from financing activities:
Proceeds from line of credit payable		311,000	829,200	1,599,500
Repayment of line of credit payable		(444,600)	(695,600)	(1,720,000)
Repayment of mortgages payable		(596)	(567)	(538)
Proceeds from notes payable		692,646	0	692,913
Repayment of notes payable		(325,000)	0	(300,000)
Payment for early extinguishment of debt		(16,679)	0	(18,240)
Payment of debt issuance costs		(7,941)	(157)	(7,156)
Proceeds from issuance of common stock		126,488	542,280	345,324
Stock issuance costs		(2,223)	(17,521)	(3,947)
Payment of common stock dividends		(356,409)	(333,692)	(303,164)
Noncontrolling interest distributions		0	(776)	0
Net cash provided by (used in) financing activities		(41,254)	4,526	250,365
Net increase (decrease) in cash, cash equivalents and restricted cash		266,124	(113,155)	112,903
Cash, cash equivalents and restricted cash at beginning of year	[1]	1,112	114,267	1,364
Cash, cash equivalents and restricted cash at end of year	[1]	267,236	1,112	114,267
Supplemental disclosure of cash flow information:
Interest paid, net of amount capitalized		119,408	115,700	107,861
Supplemental disclosure of noncash investing and financing activities:
Change in other comprehensive income (loss)		(5,317)	(5,432)	8,042
Right-of-use assets recorded in connection with lease liabilities		0	8,224	0
Work in progress accrual balance		5,602	21,579	16,603
Change in lease classification (direct financing lease to operating lease)		3,000	3,100	0
Change in lease classification (direct financing lease to operating lease)		0	1,246	565
Change in lease classification (operating lease to direct financing lease)		0	0	258
Series E Preferred Stock
Cash flows from financing activities:
Redemption of preferred stock		0	(287,500)	0
Payment of preferred stock dividends		0	(13,201)	(16,387)
Series F Preferred Stock
Cash flows from financing activities:
Payment of preferred stock dividends		$ (17,940)	$ (17,940)	$ (17,940)

[1] Cash, cash equivalents and restricted cash is the aggregate of cash and cash equivalents and restricted cash and cash held in escrow from the Consolidated Balance Sheets. NNN did not have restricted cash, including cash held in escrow as of December 31, 2020, 2019 and 2018.