Related Party Transactions and Arrangements (New York (405 Park) Office) (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Related Party Transaction [Line Items]
Payments for Capital Improvements	$ 34,687,000	$ 9,755,000	$ 54,000
New York (405 Park) Office [Member]
Related Party Transaction [Line Items]
Payments for Capital Improvements	1,100,000
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	203,558,000	0	0
Affiliated Entity [Member] | New York (405 Park) Office [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	1,659,000	0	0
Payments of related party expenses	$ 600,000