Interest and Debt Expense - Details of Interest and Debt Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Interest And Debt Expense [Abstract]
Interest expense	$ 31,999	$ 36,604	$ 66,287	$ 72,465
Amortization of deferred financing costs	2,818	1,405	5,548	2,663
Total interest and debt expense	$ 34,817	$ 38,009	$ 71,835	$ 75,128