Derivatives - Components Of The Unrealized Gain On Designated Cash Flow Hedge (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
Derivatives
Change in fair value of derivatives		$ (12.1)		$ 40.2		$ (12.4)
Tax expense		(0.2)		(0.5)		(4.3)
Unrealized gain on designated cash flow hedge	[1]	0.7	[2]	1.4	[3]	13.9	[4]
Interest rate swaps
Derivatives
Change in fair value of derivatives		$ 0.9		$ 1.9		$ 18.2

[1] Includes tax expense of $0.2 million, $0.5 million, and $4.3 million for the years ended December 31, 2023, 2022, and 2021, respectively.

[2] Includes tax expense of $0.2 million.

[3] Includes tax expense of $0.5 million.

[4] Includes tax expense of $4.3 million.