Organization and Summary of Significant Accounting Policies (Summary of NNN's Investment Portfolio) (Details) ft² in Thousands	12 Months Ended
	Dec. 31, 2016 ft² property state
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Total properties | property	2,535
Gross leasable area (square feet) | ft²	27,204
States | state	48
Weighted average remaining lease term (years)	11 years 7 months