(Expense from Transaction Related Costs and Impairment Losses) and Gain from Lease Liability Extinguishment, Net (Schedule of Lease Liability Extinguishment Gain (Transaction Related Costs and Impairment Losses)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Transaction Related Costs, Impairment Losses and Lease Termination Gain [Line Items]
Other non-cash impairment loss	$ 0	$ 0	$ 0	$ (7,500)
Transaction related costs, impairment losses and other	(584)	(1,576)	68,566	(103,315)
608 Fifth Avenue
Transaction Related Costs, Impairment Losses and Lease Termination Gain [Line Items]
Transaction related costs	(584)	(1,576)	(1,694)	(1,955)
608 Fifth Avenue non-cash lease liability extinguishment gain (impairment loss)	$ 0	$ 0	$ 70,260	$ (93,860)