Other Income (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Other income	$ 16.9	$ 15.3
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Other income	13.3
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Other income	3.6
Third Party Providers [Member]
Disaggregation of Revenue [Line Items]
Other income	13.2
Dealers [Member]
Disaggregation of Revenue [Line Items]
Other income	3.7
Ancillary Product Profit Sharing [Member]
Disaggregation of Revenue [Line Items]
Other income	7.3	7.5
Ancillary Product Profit Sharing [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Other income	7.3
Ancillary Product Profit Sharing [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0
Ancillary Product Profit Sharing [Member] | Third Party Providers [Member]
Disaggregation of Revenue [Line Items]
Other income	7.3
Ancillary Product Profit Sharing [Member] | Dealers [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0
Interest [Member]
Disaggregation of Revenue [Line Items]
Other income	5.8	4.1
Interest [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Other income	5.8
Interest [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0
Interest [Member] | Third Party Providers [Member]
Disaggregation of Revenue [Line Items]
Other income	5.8
Interest [Member] | Dealers [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0
Remarketing Fees [Member]
Disaggregation of Revenue [Line Items]
Other income	3.3	3.0
Remarketing Fees [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0
Remarketing Fees [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Other income	3.3
Remarketing Fees [Member] | Third Party Providers [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0
Remarketing Fees [Member] | Dealers [Member]
Disaggregation of Revenue [Line Items]
Other income	3.3
Other [Member]
Disaggregation of Revenue [Line Items]
Other income	0.5	$ 0.7
Other [Member] | Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Other income	0.2
Other [Member] | Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Other income	0.3
Other [Member] | Third Party Providers [Member]
Disaggregation of Revenue [Line Items]
Other income	0.1
Other [Member] | Dealers [Member]
Disaggregation of Revenue [Line Items]
Other income	$ 0.4