Basis of Presentation (Other Expense (Income), Net) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accounting Policies [Abstract]
Write-offs of deposits and pre-acquisition costs	$ (2,311)	$ (2,516)	$ (6,643)	$ (5,433)
Amortization of intangible assets	(5,045)	(3,550)	(9,602)	(7,000)
Loss on debt retirement (see Note 4)	0	(4,843)	0	(4,843)
Interest income	1,326	4,471	5,133	9,420
Interest expense	(3,000)	(146)	(3,796)	(290)
Equity in earnings of unconsolidated entities	334	129	902	165
Miscellaneous, net	3,410	2,956	6,196	3,508
Total other expense, net	$ (5,286)	$ (3,499)	$ (7,810)	$ (4,473)