Discontinued Operations Discontinued Operations (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation, Gross Disposition Price	$ 1,112,300	$ 115,300
Properties Sold Outside Triple Net Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation, Gross Disposition Price	41,600
Non Core [Member] | Citizens (CFG) Pennsylvania Dallastown, PA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date	Feb. 06, 2014
Discontinued Operation, Gross Disposition Price	100
Area of Real Estate Property	2,995
Retail [Member] | Willis Town Center Willis, TX [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date	Jan. 08, 2014
Discontinued Operation, Gross Disposition Price	1,600
Area of Real Estate Property	85,828
Retail [Member] | Alcoa Exchange I & II [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date	Jan. 29, 2014
Discontinued Operation, Gross Disposition Price	24,300
Area of Real Estate Property	339,690
Retail [Member] | Hunting Bayou Portfolio - 5 Properties [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date	Feb. 19, 2014
Discontinued Operation, Gross Disposition Price	$ 15,600
Area of Real Estate Property	276,416