Mortgages Payable (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
Debt Instrument [Line Items]
Outstanding Principal Balance	$ 9,475,000		$ 10,602,000
Mortgages
Debt Instrument [Line Items]
Carrying Value of Encumbered Asset(s)	23,120,000	[1]
Outstanding Principal Balance	9,475,000		10,602,000
Long-term Debt, Fiscal Year Maturity [Abstract]
2014	1,158,000
2015	1,207,000
2016	6,842,000
2017	147,000
2018	86,000
Thereafter	35,000
December 2001 - $623 | Mortgages
Debt Instrument [Line Items]
Initial Balance	623,000	[2]
Interest Rate	9.00%	[2]
Carrying Value of Encumbered Asset(s)	438,000	[1],[2]
Outstanding Principal Balance	27,000	[2]	95,000	[2]
December 2001 - $698 | Mortgages
Debt Instrument [Line Items]
Initial Balance	698,000	[2]
Interest Rate	9.00%	[2]
Carrying Value of Encumbered Asset(s)	968,000	[1],[2]
Outstanding Principal Balance	263,000	[2]	299,000	[2]
December 2001 - $485 | Mortgages
Debt Instrument [Line Items]
Initial Balance	485,000	[2]
Interest Rate	9.00%	[2]
Carrying Value of Encumbered Asset(s)	936,000	[1],[2]
Outstanding Principal Balance	136,000	[2]	155,000	[2]
February 2004 - $6,952 | Mortgages
Debt Instrument [Line Items]
Initial Balance	6,952,000	[2]
Interest Rate	6.90%	[2]
Carrying Value of Encumbered Asset(s)	10,797,000	[1],[2]
Outstanding Principal Balance	2,257,000	[2]	2,892,000	[2]
March 2005 - $1,015 | Mortgages
Debt Instrument [Line Items]
Initial Balance	1,015,000	[2]
Interest Rate	8.14%	[2]
Carrying Value of Encumbered Asset(s)	1,264,000	[1],[2]
Outstanding Principal Balance	335,000	[2]	439,000	[2]
June 2012 - $6,850 | Mortgages
Debt Instrument [Line Items]
Initial Balance	6,850,000	[2],[3]
Interest Rate	5.75%	[2],[3]
Carrying Value of Encumbered Asset(s)	8,717,000	[1],[2],[3]
Outstanding Principal Balance	$ 6,457,000	[2],[3]	$ 6,722,000	[2],[3]

[1] Each loan is secured by a first mortgage lien on certain of NNN’s properties. The carrying values of the assets are as of December 31, 2013.

[2] Date entered represents the date that NNN acquired real estate subject to a mortgage securing a loan. The corresponding original principal balance represents the outstanding principal balance at the time of acquisition.

[3] Initial balance and outstanding principal balance includes unamortized premium.