Related Party Transactions and Arrangements (Management Fees to Affiliates) (Details) (Former Manager and Affiliates of Former Manager [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Management Fees To Affiliates [Member]
Related Party Transaction [Line Items]
Related party expenses	$ 13,888,000	$ 17,462,000	$ 212,000
Base Management Fees [Member]
Related Party Transaction [Line Items]
Related party expenses	0	4,969,000	212,000
Asset Management Fees [Member]
Related Party Transaction [Line Items]
Related party expenses	13,888,000	11,693,000	0
Property Management Fees [Member]
Related Party Transaction [Line Items]
Related party expenses	$ 0	$ 800,000	$ 0