Fee and Other Income - Schedule of Fee and Other Income (Parenthetical) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fee And Other Income [Line Items]
Lease termination income	$ 2,189	$ 17,010	$ 871
1633 Broadway [Member]
Fee And Other Income [Line Items]
Lease termination income		$ 10,861