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Fair Value Measurements (Narrative) (Details) $ in Thousands, gal in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025 USD ($) Swap $ / gal € / shares	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) Swap $ / gal € / shares gal	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Derivatives Fair Value [Line Items]
Debt instrument, face amount	$ 325,000		$ 325,000
Fair Value, Inputs, Level 1 [Member]
Derivatives Fair Value [Line Items]
Fair value of debt	312,300		$ 312,300
Fuel Hedge Contracts [Member]
Derivatives Fair Value [Line Items]
Derivative underlying hedge percent			90.00%
Derivative, nonmonetary notional amount, volume | gal			15.8
Reclassification of derivative gain (losses) to earnings net of tax	(522)	$ (359)	$ (642)	$ (238)
Fair value hedge liabilities	$ 500		$ 500		$ 1,100
Fuel Hedge Contracts [Member] | Minimum [Member]
Derivatives Fair Value [Line Items]
Fixed price range | $ / gal	2.03		2.03
Fuel Hedge Contracts [Member] | Maximum [Member]
Derivatives Fair Value [Line Items]
Fixed price range | $ / gal	2.66		2.66
Foreign Currency Exchange Hedge Contracts [Member]
Derivatives Fair Value [Line Items]
Reclassification of derivative gain (losses) to earnings net of tax		$ (6)		(42)
Reclassification of derivative (gains) losses to earnings net of cash settlements and taxes				$ 42
Foreign Currency Exchange Hedge Contracts [Member] | Minimum [Member]
Derivatives Fair Value [Line Items]
Fixed price range | € / shares	1.01		1.01
Foreign Currency Exchange Hedge Contracts [Member] | Maximum [Member]
Derivatives Fair Value [Line Items]
Fixed price range | € / shares	1.13		1.13
Interest Rate Swaps [Member]
Derivatives Fair Value [Line Items]
Reclassification of derivative gain (losses) to earnings net of tax	$ 64		$ 132
Derivative notional amount	75,000		75,000
Fair value hedge liabilities	$ 109		$ 109
Derivative, maturity date			Aug. 24, 2026
Floating-rate debt to weighted average fixed interest rate	11.62%		11.62%
Derivative, average fixed interest rate	3.87%		3.87%
Number of interest rate swaps | Swap	2		2

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