Commitments And Contingencies (Narrative) (Details) - USD ($)			3 Months Ended	12 Months Ended
	Sep. 19, 2019	Feb. 07, 2019	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Rent expense				$ 5,000,000	$ 4,500,000	$ 4,400,000
Rental charged to subtenants				586,300	186,300	100,200
SEC settlement	$ 1,400,000			$ (8,900,000)	$ 290,000	$ (2,290,000)
Seabreeze Development [Member]
Investment by plaintiff, allegedly defrauded		$ 12,000,000	$ 10,500,000