Real Estate Investments (Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
2015 Acquisitions [Member]
Assets Acquired and Liabilities Assumed
Land	$ 2,047
Buildings, fixtures and improvements	5,258
Land and construction in progress	2,140
Total tangible assets	9,445
In-place leases	717
Above-market leases	153
Below-market leases	(108)
Fair value adjustment of assumed notes payable	0
Total purchase price of assets acquired, net	10,207
Mortgage notes payable assumed	0
Cash paid for acquired real estate investments	$ 10,207
2014 Acquisitions, Excluding Cole Merger, ARCT IV Merger And CCPT Merger [Member]
Assets Acquired and Liabilities Assumed
Land		$ 812,712
Buildings, fixtures and improvements		2,486,868
Land and construction in progress		11,083
Total tangible assets		3,310,663
In-place leases		522,568
Above-market leases		110,230
Below-market leases		(101,108)
Fair value adjustment of assumed notes payable		(23,531)
Total purchase price of assets acquired, net		3,818,822
Mortgage notes payable assumed		(301,532)
Cash paid for acquired real estate investments		$ 3,517,290