Interest and Debt Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest and Debt Expense [Abstract]
Interest expense	$ 96,377	$ 88,392	$ 191,165	$ 173,362
Amortization of deferred financing costs	8,034	7,977	16,138	16,546
Capitalized interest and debt expense	(16,754)	(11,580)	(31,480)	(22,395)
Interest and debt expense, Total	$ 87,657	$ 84,789	$ 175,823	$ 167,513