Debt And Liquidity (Schedule Of Long-Term Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total debt	$ 1,127,540	$ 1,420,131
Less: Short-term debt	(128)	(131)
Long-term debt	1,127,412	1,420,000
2018 Credit Facility (2018 Term Loan and 2018 Revolving Credit Facility)
Debt Instrument [Line Items]
Long-term Debt, Gross	643,708	943,708
2020 Senior Notes
Debt Instrument [Line Items]
Long-term Debt, Gross	500,000	500,000
Other debt
Debt Instrument [Line Items]
Long-term Debt, Gross	583	615
Unamortized debt discount and issuance costs
Debt Instrument [Line Items]
Unamortized debt discount and issuance costs	$ (16,751)	$ (24,192)

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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