Real Estate Investments (Narrative) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2015 USD ($) land_parcel property	Jun. 30, 2014 USD ($) property
Business Acquisition [Line Items]
Purchase price	$ 41,100
2015 Acquisitions [Member]
Business Acquisition [Line Items]
Number of properties acquired | property	14
Development projects in progress | land_parcel	9
Purchase price	$ 10,200
Total purchase price of assets acquired, net	$ 10,207
2014 Acquisitions, Excluding Cole Merger, ARCT IV Merger And CCPT Merger [Member]
Business Acquisition [Line Items]
Number of properties acquired | property		337
Total purchase price of assets acquired, net		$ 1,548,120