Related Party Transactions and Arrangements (Indirect Affiliate Expenses) (Details) - Affiliates of Former Manager [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Indirect Affiliate Expenses [Member]
Related Party Transaction [Line Items]
Related party expenses	$ 0	$ 5,595	$ 0	$ 10,090
Audrain Building [Member]
Related Party Transaction [Line Items]
Related party expenses	0	4,769	0	8,691
ANST Office Build-Out [Member]
Related Party Transaction [Line Items]
Related party expenses	0	114	0	449
New York (405 Park Ave.) Office [Member]
Related Party Transaction [Line Items]
Related party expenses	0	677	0	864
Dresher, PA Office [Member]
Related Party Transaction [Line Items]
Related party expenses	0	24	0	60
North Carolina Office [Member]
Related Party Transaction [Line Items]
Related party expenses	$ 0	$ 11	$ 0	$ 26