Derivatives - Interest Rate Swaps (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Derivatives
Tax expense			$ (1.1)
Unrealized gain on designated cash flow hedge	[1]	$ 0.1	3.6	[2]
Interest expense		0.1	4.8
Interest expense expected to be reclassified out of accumulated other comprehensive income (loss) over the next twelve months		0.1
Interest rate swaps
Derivatives
Change in fair value of interest rate swaps		0.1	4.7
Tax expense		0.0	(1.1)
Unrealized gain on designated cash flow hedge		$ 0.1	$ 3.6

[1] Includes tax expense of $1.1 million for the three months ended March 31, 2021.

[2] Includes tax expense of $1.1 million.