Derivatives - Interest Rate Swaps (Details) - USD ($) $ in Millions	3 Months Ended									9 Months Ended
	Sep. 30, 2023		Jun. 30, 2023		Mar. 31, 2023		Sep. 30, 2022		Mar. 31, 2022	Sep. 30, 2023		Sep. 30, 2022		Dec. 31, 2022
Derivatives
Tax expense	$ (0.5)		$ (1.8)		$ 0.4					$ (1.9)
Unrealized gain on designated cash flow hedge	1.7	[1],[2]	$ 5.7	[1]	$ (1.2)	[1]	$ 0.0	[2]	$ 0.1	6.2	[2]	$ 0.1	[2]
Fair value of derivative assets—current	68.0									68.0				$ 68.4
Fair value of derivative assets	13.8									13.8				2.9
Interest expense, net of interest income	(1.4)						0.0			(3.0)		0.1
Interest rate swaps
Derivatives
Change in fair value of interest rate swaps	2.2						0.0			8.1		0.1
Tax expense	(0.5)						0.0			(1.9)		0.0
Unrealized gain on designated cash flow hedge	1.7						$ 0.0			6.2		$ 0.1
Fair value of derivative assets—current	5.7									5.7				0.0
Fair value of derivative assets	2.4									2.4				0.0
Net fair value of commodity derivatives	$ 8.1									$ 8.1				$ 0.0

[1] Includes tax benefit of $0.4 million for the three months ended March 31, 2023, tax expense of $1.8 million for the three months ended June 30, 2023, and tax expense of $0.5 million for the three months ended September 30, 2023.

[2] Includes tax expense of $0.5 million and $1.9 million for the three and nine months ended September 30, 2023, respectively.