CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net earnings		$ 265,371,000	$ 239,506,000	$ 197,961,000
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization		173,720,000	149,101,000	134,798,000
Impairment losses – real estate and other charges, net of recoveries		4,953,000	11,294,000	4,420,000
Impairment – commercial mortgage residual interests valuation		0	6,830,000	531,000
Amortization of notes payable discount		1,788,000	1,394,000	1,306,000
Amortization of debt costs		3,502,000	3,086,000	2,915,000
Amortization of mortgages payable premium		(85,000)	(147,000)	(207,000)
Amortization of deferred interest rate hedges		1,932,000	2,802,000	1,902,000
Settlement of forward starting swaps		(7,688,000)	13,345,000	(13,369,000)
Gain on disposition of real estate		(36,655,000)	(27,182,000)	(10,807,000)
Deferred income taxes		0	0	10,488,000
Performance incentive plan expense		14,223,000	11,401,000	10,474,000
Performance incentive plan payment		(862,000)	(581,000)	(676,000)
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		884,000	1,364,000	1,277,000
Increase in receivables		(175,000)	(74,000)	(335,000)
Increase in accrued rental income		(1,752,000)	(252,000)	(368,000)
Decrease in other assets		1,960,000	1,663,000	4,996,000
Increase (decrease) in accrued interest payable		646,000	(448,000)	2,717,000
Increase (decrease) in other liabilities		(90,000)	2,636,000	(6,610,000)
Other		(115,000)	(401,000)	(318,000)
Net cash provided by operating activities		421,557,000	415,337,000	341,095,000
Cash flows from investing activities:
Proceeds from the disposition of real estate		97,245,000	104,117,000	38,502,000
Additions to real estate:
Accounted for using the operating method		(721,893,000)	(885,966,000)	(683,243,000)
Principal payments on mortgages and notes receivable		1,250,000	4,141,000	2,363,000
Other		(2,159,000)	(2,235,000)	(2,166,000)
Net cash used in investing activities		(625,557,000)	(779,943,000)	(644,544,000)
Cash flows from financing activities:
Proceeds from line of credit payable		1,501,700,000	1,330,200,000	1,262,400,000
Repayment of line of credit payable		(1,381,200,000)	(1,330,200,000)	(1,262,400,000)
Repayment of mortgages payable		(510,000)	(9,962,000)	(2,035,000)
Proceeds from notes payable		398,372,000	346,140,000	399,036,000
Repayment of notes payable		(250,000,000)	0	(150,000,000)
Payment of debt costs		(7,837,000)	(3,362,000)	(3,654,000)
Proceeds from issuance of common stock		256,764,000	278,040,000	332,117,000
Stock issuance costs		(3,836,000)	(15,204,000)	(4,198,000)
Payment of common stock dividends		(277,120,000)	(257,007,000)	(228,699,000)
Noncontrolling interest contributions		0	0	334,000
Noncontrolling interest distributions		(84,000)	(136,000)	(362,000)
Net cash provided by (used in) financing activities		(89,176,000)	644,886,000	307,105,000
Net increase (decrease) in cash, cash equivalents and restricted cash		(293,176,000)	280,280,000	3,656,000
Cash, cash equivalents and restricted cash at beginning of year	[1]	294,540,000	14,260,000	10,604,000
Cash, cash equivalents and restricted cash at end of year	[1]	1,364,000	294,540,000	14,260,000
Supplemental disclosure of cash flow information:
Interest paid, net of amount capitalized		103,761,000	91,403,000	83,758,000
Taxes paid (received)		(15,000)	(155,000)	234,000
Supplemental disclosure of noncash investing and financing activities:
Change in other comprehensive income		5,547,000	12,161,000	11,694,000
Change in lease classification (direct financing lease to operating lease)		696,000	1,924,000	1,179,000
Mortgage receivable accepted in connection with real estate transactions		0	0	500,000
Series D Preferred Stock
Cash flows from financing activities:
Redemption of Series D preferred stock		(287,500,000)	0	0
Payment of preferred stock dividends		(3,598,000)	(19,047,000)	(19,047,000)
Series E Preferred Stock
Cash flows from financing activities:
Payment of preferred stock dividends		(16,387,000)	(16,387,000)	(16,387,000)
Series F Preferred Stock
Cash flows from financing activities:
Proceeds from issuance of Series F preferred stock		0	345,000,000	0
Payment of preferred stock dividends		$ (17,940,000)	$ (3,189,000)	$ 0

[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 or cash held in escrow at December 31, 2017 and 2016 and had $601 at December 31, 2015.