Other Income (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Disaggregation of Revenue [Line Items]
Other income	$ 19.0	$ 16.2	$ 39.9	$ 33.1
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Other income	15.4		32.6
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Other income	3.6		7.3
Third Party Providers [Member]
Disaggregation of Revenue [Line Items]
Other income	15.3		32.5
Dealers [Member]
Disaggregation of Revenue [Line Items]
Other income	3.7		7.4
Ancillary Product Profit Sharing [Member]
Disaggregation of Revenue [Line Items]
Other income	7.5	6.4	16.2	13.7
Ancillary Product Profit Sharing [Member] \| Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Other income	7.5		16.2
Ancillary Product Profit Sharing [Member] \| Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0		0.0
Ancillary Product Profit Sharing [Member] \| Third Party Providers [Member]
Disaggregation of Revenue [Line Items]
Other income	7.5		16.2
Ancillary Product Profit Sharing [Member] \| Dealers [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0		0.0
Interest [Member]
Disaggregation of Revenue [Line Items]
Other income	7.8	6.4	16.2	12.2
Interest [Member] \| Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Other income	7.8		16.2
Interest [Member] \| Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0		0.0
Interest [Member] \| Third Party Providers [Member]
Disaggregation of Revenue [Line Items]
Other income	7.8		16.2
Interest [Member] \| Dealers [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0		0.0
Remarketing Fees [Member]
Disaggregation of Revenue [Line Items]
Other income	3.3	2.9	6.7	6.2
Remarketing Fees [Member] \| Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0		0.0
Remarketing Fees [Member] \| Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Other income	3.3		6.7
Remarketing Fees [Member] \| Third Party Providers [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0		0.0
Remarketing Fees [Member] \| Dealers [Member]
Disaggregation of Revenue [Line Items]
Other income	3.3		6.7
Other [Member]
Disaggregation of Revenue [Line Items]
Other income	0.4	$ 0.5	0.8	$ 1.0
Other [Member] \| Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Other income	0.1		0.2
Other [Member] \| Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Other income	0.3		0.6
Other [Member] \| Third Party Providers [Member]
Disaggregation of Revenue [Line Items]
Other income	0.0		0.1
Other [Member] \| Dealers [Member]
Disaggregation of Revenue [Line Items]
Other income	$ 0.4		$ 0.7