Deferred Costs - Amortization Expense (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Deferred Costs [Abstract]
Amortization of deferred financing costs	$ 2,384	$ 1,912
Amortization of deferred leasing costs, lease intangibles and other	$ 17,538	$ 11,501