Fair Value Measurements and Derivative Instruments (Fuel Price Risk) (Details) - Fuel Price Risk $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) T	Dec. 31, 2022 USD ($) T
Derivative instruments disclosure
Discontinued cash flow hedge, nonmonetary amount | T	200,000
Discontinued cash flow hedge, reclassification loss | $	$ 0.7
Estimated unrealized net gains (losses) associated with cash flow hedges pertaining to fuel swap agreements expected to be reclassified to earnings from other accumulated comprehensive income (loss) | $	$ (23.8)	$ (7.9)
2023
Derivative instruments disclosure
Fuel Swap Agreements (metric tons) | T	249,050,000	825,651,000
Percentage of projected requirements	15.00%	50.00%