Interest and Debt Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest and Debt Expense [Abstract]
Interest expense	$ 94,788	$ 84,970
Amortization of deferred financing costs	8,104	8,569
Capitalized interest and debt expense	(14,726)	(10,815)
Interest and debt expense, Total	$ 88,166	$ 82,724