Interest and Debt Expense - Details of Interest and Debt Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Interest And Debt Expense [Abstract]
Interest expense	$ 34,388	$ 34,055	$ 68,511	$ 67,376
Amortization of deferred financing costs	2,825	2,754	5,626	5,515
Total interest and debt expense	$ 37,213	$ 36,809	$ 74,137	$ 72,891