Fair Value Measurements And Derivative Instruments Fair Value Measurements And Derivative Instruments (Schedule Of Fair Value Of Derivatives) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Commodity derivative contracts
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 8,500
Liability Derivatives		$ (2,200)
Derivatives designated as cash flow hedges:
Derivatives, Fair Value [Line Items]
Asset Derivatives	14,529	581
Liability Derivatives	140	13,769
Derivatives designated as cash flow hedges: | Commodity derivative contracts | Prepaid and other current assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	8,469	518
Derivatives designated as cash flow hedges: | Commodity derivative contracts | Other accrued liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	0	888
Derivatives designated as cash flow hedges: | Commodity derivative contracts | Other assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	0	63
Derivatives designated as cash flow hedges: | Commodity derivative contracts | Other long-term obligations
Derivatives, Fair Value [Line Items]
Liability Derivatives	0	1,898
Derivatives designated as cash flow hedges: | Interest rate swap | Prepaid and other current assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	0	0
Derivatives designated as cash flow hedges: | Interest rate swap | Other accrued liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	140	4,080
Derivatives designated as cash flow hedges: | Interest rate swap | Other assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	6,060	0
Derivatives designated as cash flow hedges: | Interest rate swap | Other long-term obligations
Derivatives, Fair Value [Line Items]
Liability Derivatives	0	6,903
Derivatives not designated as hedges:
Derivatives, Fair Value [Line Items]
Asset Derivatives	388	6
Liability Derivatives	2	1,063
Derivatives not designated as hedges: | Interest rate swap | Prepaid and other current assets
Derivatives, Fair Value [Line Items]
Asset Derivatives		0
Derivatives not designated as hedges: | Interest rate swap | Other accrued liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives		952
Derivatives not designated as hedges: | Foreign currency derivatives | Prepaid and other current assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	388	6
Derivatives not designated as hedges: | Foreign currency derivatives | Other accrued liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 2	$ 111