Organization And Summary Of Significant Accounting Policies (Computation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Net earnings attributable to NNN	$ 27,570	$ 22,632	$ 21,303	$ 20,820	$ 14,215	$ 21,210	$ 21,207	$ 16,365	$ 92,325	$ 72,997	$ 54,810
Less: Series C preferred stock dividends									(6,785)	(6,785)	(6,785)
Net earnings attributable to common stockholders									85,540	66,212	48,025
Less: Earnings attributable to unvested restricted shares									(622)	(299)	(290)
Net earnings used in basic earnings per share									84,918	65,913	47,735
Reallocated undistributed income (loss)									(2)	0	(1)
Net earnings used in diluted earnings per share									$ 84,916	$ 65,913	$ 47,734
Weighted average number of shares outstanding									88,972,723	83,320,921	80,486,215
Less: unvested restricted stock									(630,102)	(605,276)	(639,957)
Less: contingent shares									242,545	0	0
Weighted average number of shares outstanding used in basic earnings per share									88,100,076	82,715,645	79,846,258
Incremental Common Shares Attributable To Contingently Issuable Shares, Diluted									66,001	0	0
Convertible debt									512,024	0	0
Common stock options									2,881	3,814	9,037
Directors' deferred fee plan									156,075	129,903	98,204
Weighted average number of shares outstanding used in diluted earnings per share									88,837,057	82,849,362	79,953,499