Schedule III - Real Estate and Accumulated Depreciation and Amortization Notes to Schedule III (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Balance at the beginning of year	$ 4,145,368		$ 3,531,845	$ 2,774,947
Acquisitions, completed construction and tenant improvements	602,836		701,054	772,073
Disposition of land, buildings, and leasehold interests	(57,254)		(77,219)	(14,744)
Provision for loss on impairment of real estate	(4,106)		(10,312)	(431)
Balance at the close of year	4,686,844		4,145,368	3,531,845
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance at the beginning of year	333,778		270,621	222,921
Disposition of land, buildings, and leasehold interests	(6,778)		(6,980)	(3,010)
Depreciation and amortization expense	91,136		70,137	50,710
Balance at the close of year	418,136		333,778	270,621
Work in progress	60,720		86,579	60,322
Mortgages payable, including unamortized premium of $130 and $187, respectively	9,475		10,602
Operating Lease
Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Balance at the close of year	4,609,159	[1],[2]
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Balance at the close of year	416,477
Real estate, federal income tax basis	4,565,187
Direct Financing Lease
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Real estate, federal income tax basis	2,703
Mortgage Agreement-2
Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Mortgages payable, including unamortized premium of $130 and $187, respectively	$ 6,952

[1] As of December 31, 2013, the leases are treated as either operating or financing leases for federal income tax purposes. As of December 31, 2013, the aggregate cost of the properties owned by NNN that are under operating leases were $4,565,187 and financing leases were $2,703.

[2] Transactions in real estate and accumulated depreciation during 2013, 2012, and 2011 are summarized as follows: 2013 2012 2011Land, buildings, and leasehold interests: Balance at the beginning of year$4,145,368 $3,531,845 $2,774,947Acquisitions, completed construction and tenant improvements602,836 701,054 772,073Disposition of land, buildings, and leasehold interests(57,254) (77,219) (14,744)Provision for loss on impairment of real estate(4,106) (10,312) (431)Balance at the close of year$4,686,844 $4,145,368 $3,531,845Accumulated depreciation and amortization: Balance at the beginning of year$333,778 $270,621 $222,921Disposition of land, buildings, and leasehold interests(6,778) (6,980) (3,010)Depreciation and amortization expense91,136 70,137 50,710Balance at the close of year$418,136 $333,778 $270,621