Summary of Significant Accounting Policies (Other Expense (Income), Net) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other expense (income), net [Line Items]
Write-off of deposits and pre-acquisition costs	$ (9,600)	$ (13,116)	$ (16,992)	$ (11,367)
Interest Expense		(584)	(618)	(503)
Amortization of intangible assets		(14,200)	(13,800)	(13,800)
Gain (Loss) on Extinguishment of Debt		(4,927)	(76)	0
Equity in (earnings) loss of unconsolidated entities		747	2,690	(1,985)
Other Nonoperating Income		1,865	7,354
Interest expense		(16,739)	(7,593)	(2,537)
Other expense, net		13,476	13,849	32,387
Other Nonoperating Expense				(7,269)
Impairment Losses Related to Real Estate Partnerships		$ 0	$ 0	$ 8,018