Disposed Properties (Details 2) (USD $) In Thousands, unless otherwise specified	9 Months Ended		0 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	May 08, 2014 Non Core [Member]	Sep. 30, 2014 Oak Park Dallas, TX [Member] Land [Member]	Sep. 30, 2014 Willis Town Center Willis, TX [Member] Retail [Member] sqft	Sep. 30, 2014 Alcoa Exchange I & II [Member] Retail [Member] sqft	Sep. 30, 2014 Citizens (CFG) Pennsylvania Dallastown, PA [Member] Non Core [Member] sqft	Sep. 30, 2014 Hunting Bayou Portfolio - 5 Properties [Member] Retail [Member] sqft	Sep. 30, 2014 Monadnock Marketplace & Condo [Member] Retail [Member] sqft	Sep. 30, 2014 Block 121 & Block 121 Retail [Member] Non Core [Member] Units	Sep. 30, 2014 Palm Harbor Shopping Center [Member] Retail [Member] sqft	Sep. 30, 2014 Crown Plaza Charleston [Member] Lodging [Member] Room	Sep. 30, 2014 Imagine Charter Schools - 8 Properties [Member] Non Core [Member] sqft	Sep. 30, 2014 Citizens - 88 York [Member] Non Core [Member] sqft	Sep. 30, 2014 Merchant's Crossing [Member] Retail [Member] sqft	Sep. 30, 2014 3801 South Collins [Member] Non Core [Member] sqft	Sep. 30, 2014 Sonora [Member] Non Core [Member] sqft	Sep. 30, 2014 Doubletree Atlanta Galleria [Member] Lodging [Member] Room	Sep. 30, 2014 Properties Sold Outside Triple Net Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date			May 08, 2014		Jan. 08, 2014	Jan. 29, 2014	Feb. 06, 2014	Feb. 19, 2014	Apr. 09, 2014	Apr. 16, 2014	May 15, 2014	May 30, 2014	Aug. 28, 2014	Jul. 09, 2014	Jul. 22, 2014	Jul. 31, 2014	Jul. 31, 2014	Aug. 28, 2014
Discontinued Operation, Gross Disposition Price	$ 1,476,500	$ 1,815,900		$ 14,000	$ 1,600	$ 24,300	$ 100	$ 15,600	$ 31,200	$ 38,200	$ 12,400	$ 13,300	$ 68,400	$ 500	$ 17,900	$ 10,500	$ 7,000	$ 12,600	$ 253,600
Number of Units in Real Estate Property										255		168						154
Area of Real Estate Property					85,828	339,690	2,995	276,416	367,454		161,431		364,710	17,079	213,739	239,905	33,055