Consolidated Statements of Income (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Fees to Vornado	$ 4,671	$ 4,590	$ 4,476
Management fees to Vornado	$ 2,380	$ 2,380	$ 2,380