Schedule III - Real Estate and Accumulated Depreciation and Amortization Real Estate - Held for Sale (Details) (USD $) In Thousands, unless otherwise specified																	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013 Assets Held-for-sale Chipotle Hadley, MA		Dec. 31, 2013 Assets Held-for-sale Power Center Big Flats, NY		Dec. 31, 2013 Assets Held-for-sale Power Center Irving, TX		Dec. 31, 2013 Assets Held-for-sale Vacant Land Grand Prairie, TX		Dec. 31, 2013 Assets Held-for-sale Vacant Land Rockwall, TX		Dec. 31, 2013 Assets Held-for-sale Vacant Land Hadley, MA		Dec. 31, 2013 Assets Held-for-sale Vacant Property Winfield, AL		Dec. 31, 2013 Assets Held-for-sale Vacant Property Corpus Christi, TX		Dec. 31, 2013 Assets Held-for-sale Vacant Property Charlotte, NC		Dec. 31, 2013 Assets Held-for-sale Real Estate – Held for Sale
Real Estate and Accumulated Depreciation [Line Items]
Real Estate and Accumulated Depreciation, Encumbrances					$ 0		$ 0		$ 0		$ 0		$ 0		$ 0		$ 0		$ 0		$ 0		$ 0
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land					45		2,248		951		387		900		2,824		420		224		1,025		9,024
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests					0		7,159		1,090		0		0		0		1,685		2,159		1,605		13,698
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements					0		1,222		0		0		0		0		0		145		0		1,367
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs					0		0		0		0		0		0		0		0		0		0
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land					43	[1],[2]	2,248	[1],[2]	951	[1],[2]	108	[1],[2]	545	[1],[2]	1,839	[1],[2]	420	[1],[2]	224	[1],[2]	1,025	[1],[2]	7,403	[1],[2]
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests					0	[1],[2]	5,039	[1],[2]	1,063	[1],[2]	0	[1],[2]	0	[1],[2]	0	[1],[2]	707	[1],[2]	1,359	[1],[2]	1,395	[1],[2]	9,563	[1],[2]
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests	4,686,844	4,145,368	3,531,845	2,774,947	43	[1],[2]	7,287	[1],[2]	2,014	[1],[2]	108	[1],[2]	545	[1],[2]	1,839	[1],[2]	1,127	[1],[2]	1,583	[1],[2]	2,420	[1],[2]	16,966	[1],[2]
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization	$ 418,136	$ 333,778	$ 270,621	$ 222,921			$ 0		$ 0								$ 602		$ 753		$ 304		$ 1,659
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed																	40 years		40 years		30 years

[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