Notes Payable (Notes)	9 Months Ended
Sep. 30, 2018
Notes Payable [Abstract]
Notes Payable	Notes Payable: In September 2018, NNN filed a prospectus supplement to the prospectus contained in its February 2018 shelf registration statement and issued $400,000,000 aggregate principal amount of 4.300% notes due October 2028 (the “2028 Notes”) and $300,000,000 aggregate principal amount of 4.800% notes due October 2048 (the "2048 Notes" and, together with the 2028 Notes, the "Notes"). The 2028 Notes were sold at a discount with an aggregate purchase price of $397,152,000 with interest payable semi-annually commencing on April 15, 2019. The discount of $2,848,000 is being amortized to interest expense over the term of the notes using the effective interest method. The effective interest rate for the 2028 Notes after accounting for the note discount is 4.388%. NNN previously entered into two forward starting swaps with an aggregate notional amount of $250,000,000. Upon issuance of the 2028 Notes, NNN terminated the forward starting swaps resulting in a gain of $4,080,000, which was deferred in other comprehensive income. The gain is being amortized to interest expense over the term of the 2028 Notes using the effective interest method. The 2048 Notes were sold at a discount with an aggregate purchase price of $295,761,000 with interest payable semi-annually commencing on April 15, 2019. The discount of $4,239,000 is being amortized to interest expense over the term of the notes using the effective interest method. The effective interest rate for the 2048 Notes after accounting for the note discount is 4.890%. The Notes are senior unsecured obligations of NNN and are subordinated to all secured indebtedness and to the indebtedness and other liabilities of NNN's subsidiaries. Additionally, the Notes are each redeemable at NNN's option, in whole or part anytime, for an amount equal to (i) the sum of the outstanding principal balance of the notes being redeemed plus accrued interest thereon to the redemption date, and (ii) the make-whole amount, if any, as defined in the supplemental indenture dated September 18, 2018, relating to the Notes. NNN received approximately $393,502,000 and $292,386,000 of net proceeds in connection with the issuance of the 2028 Notes and the 2048 Notes, respectively, after incurring debt issuance costs consisting primarily of underwriting discounts and commissions, legal and accounting fees, rating agency fees and printing expenses, totaling $3,650,000 and $3,375,000 for the 2028 Notes and the 2048 Notes, respectively. In September 2018, NNN announced that the Company will redeem the $300,000,000 5.500% notes payable due July 2021 on October 19, 2018. The notes will be redeemed at a price equal to 100% of the principal amount, plus (i) a make-whole amount of $18,240,000, and (ii) accrued and unpaid interest.

Notes Payable:

In September 2018, NNN filed a prospectus supplement to the prospectus contained in its February 2018 shelf registration statement and issued $400,000,000 aggregate principal amount of 4.300% notes due October 2028 (the “2028 Notes”) and $300,000,000 aggregate principal amount of 4.800% notes due October 2048 (the "2048 Notes" and, together with the 2028 Notes, the "Notes").

The 2028 Notes were sold at a discount with an aggregate purchase price of $397,152,000 with interest payable semi-annually commencing on April 15, 2019. The discount of $2,848,000 is being amortized to interest expense over the term of the notes using the effective interest method. The effective interest rate for the 2028 Notes after accounting for the note discount is 4.388%. NNN previously entered into two forward starting swaps with an aggregate notional amount of $250,000,000. Upon issuance of the 2028 Notes, NNN terminated the forward starting swaps resulting in a gain of $4,080,000, which was deferred in other comprehensive income. The gain is being amortized to interest expense over the term of the 2028 Notes using the effective interest method.

The 2048 Notes were sold at a discount with an aggregate purchase price of $295,761,000 with interest payable semi-annually commencing on April 15, 2019. The discount of $4,239,000 is being amortized to interest expense over the term of the notes using the effective interest method. The effective interest rate for the 2048 Notes after accounting for the note discount is 4.890%.

The Notes are senior unsecured obligations of NNN and are subordinated to all secured indebtedness and to the indebtedness and other liabilities of NNN's subsidiaries. Additionally, the Notes are each redeemable at NNN's option, in whole or part anytime, for an amount equal to (i) the sum of the outstanding principal balance of the notes being redeemed plus accrued interest thereon to the redemption date, and (ii) the make-whole amount, if any, as defined in the supplemental indenture dated September 18, 2018, relating to the Notes.

NNN received approximately $393,502,000 and $292,386,000 of net proceeds in connection with the issuance of the 2028 Notes and the 2048 Notes, respectively, after incurring debt issuance costs consisting primarily of underwriting discounts and commissions, legal and accounting fees, rating agency fees and printing expenses, totaling $3,650,000 and $3,375,000 for the 2028 Notes and the 2048 Notes, respectively.

In September 2018, NNN announced that the Company will redeem the $300,000,000 5.500% notes payable due July 2021 on October 19, 2018. The notes will be redeemed at a price equal to 100% of the principal amount, plus (i) a make-whole amount of $18,240,000, and (ii) accrued and unpaid interest.