Mergers with Real Estate Businesses (Fair Value of Assets and Liabilities Assumed at Cole Acquisition) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2015	Feb. 07, 2014	Dec. 31, 2013	Dec. 31, 2012
Identifiable liabilities assumed at fair value:
Measurement period adjustments		$ 22,288
Goodwill	$ 1,894,794	$ 1,894,794	$ 1,656,374		$ 92,789	$ 0
Cole Real Estate Investments, Inc. [Member]
Identifiable assets acquired at fair value:
Land				$ 1,737,839
Buildings, fixtures and improvements				5,901,827
Acquired intangible lease assets				1,324,217
Total real estate investments				8,963,883
Investment in unconsolidated entities				103,966
Investment securities				151,197
Loans held for investment, net				72,326
Cash and cash equivalents				149,965
Restricted cash				15,704
Intangible assets				305,000
Deferred costs and other assets				94,667
Due from affiliates				3,301
Total identifiable assets acquired				9,860,009
Identifiable liabilities assumed at fair value:
Mortgage notes payable, net				2,706,585
Credit facilities				1,309,000
Other debt				49,013
Below-market lease liabilities				212,433
Accounts payable and accrued expenses				142,243
Deferred rent, derivative and other liabilities				204,558
Dividends payable				6,271
Due to affiliates				44,242
Total liabilities assumed				4,674,345
Non-controlling interests				24,766
Net identifiable assets acquired				5,160,898
Measurement period adjustments	$ 49,627
Goodwill				2,262,547
Net assets acquired				$ 7,423,445