Condensed Consolidated Statements of Cash Flows (Parenthetical) - shares	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015
Statement of Cash Flows [Abstract]
Issued shares of restricted and unrestricted common stock, pursuant to NNN’s performance incentive plan (in shares)	281,870	279,712

Represents the number of shares of the Company's common stock issued during the period in connection with share-based compensation.

No definition available.

Name:	nnn_IssuedSharesOfRestrictedAndUnrestrictedCommonStockShares
Namespace Prefix:	nnn_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration