Comprehensive Income - Reclassifications from Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income Loss [Line Items]
Net realized loss	$ (28.8)	$ (17.3)	$ (20.7)
Reclassifications from Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income Loss [Line Items]
Reclassifications before tax		0.7	2.3
Income tax benefit		0.2	0.6
Reclassifications, net of tax		0.5	1.7
Reclassifications from Accumulated Other Comprehensive Loss | Interest Rate Collars: Net Realized Loss
Accumulated Other Comprehensive Income Loss [Line Items]
Net realized loss		$ 0.7	$ 2.3