Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Accrued capital expenditures	$ 71,769	$ 66,620
Accounts payable and accrued expenses	32,509	36,246
Payable to the estate of Leona M. Helmsley	0	18,367
Interest rate swap agreements liability	436	5,591
Accrued interest payable	5,687	6,230
Due to affiliated companies	448	1,010
Total accounts payable and accrued expenses	$ 110,849	$ 134,064