Debt (Summary Of Long-Term Debt) (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total long-term debt		$ 807,539	$ 807,565
Current portion of long-term debt		(8,764)	(8,703)
Long-term debt, less current portion		798,775	798,862
Term Loan Facility, Maturing 2024 [Member]
Debt Instrument [Line Items]
Total long-term debt	[1]	795,483	801,764
Unamortized debt issuance costs		4,000	3,900
Revolving credit facility [Member]
Debt Instrument [Line Items]
Total long-term debt		5,740
Finance Lease Obligations [Member]
Debt Instrument [Line Items]
Total long-term debt		2,610	2,305
Other notes [Member]
Debt Instrument [Line Items]
Total long-term debt		$ 3,706	$ 3,496

[1] The carrying value of the term loan facility, maturing 2024, is net of unamortized debt issuance costs of $4.0 million at September 30, 2020 and $3.9 million at December 31, 2019.