Fair Value Measures (Impairment of Assets) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($) property	Sep. 30, 2014 USD ($) property
Impaired Assets to be Disposed of by Method Other than Sale [Line Items]
Properties impaired | property	188	9
Impairments	$ 85,341	$ 3,855
Investment in real estate assets, net [Member]
Impaired Assets to be Disposed of by Method Other than Sale [Line Items]
Impairments	82,654	3,855
Investments in direct financing leases, net [Member]
Impaired Assets to be Disposed of by Method Other than Sale [Line Items]
Impairments	3,417	0
Below-market lease liabilities, net [Member]
Impaired Assets to be Disposed of by Method Other than Sale [Line Items]
Impairments	$ (730)	$ 0