Comprehensive Income (Loss) - Reclassifications from Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income Loss [Line Items]
Net realized loss	$ (5.7)	$ (4.0)
Reclassifications from Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income Loss [Line Items]
Reclassifications before tax	0.6
Income tax benefit	0.2
Reclassifications, net of tax	0.4
Reclassifications from Accumulated Other Comprehensive Loss | Change in Fair Value of Interest Rate Collars
Accumulated Other Comprehensive Income Loss [Line Items]
Net realized loss	$ 0.6