Debt (Schedule of Additional Information Related to Debt Instruments) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revolving Secured Line of Credit [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	$ 306.8	$ 240.8
Average outstanding balance	123.0	45.4
Warehouse Facility II [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	201.0	201.0
Average outstanding balance	19.0	8.9
Warehouse Facility IV [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	0.0	0.0
Average outstanding balance	0.0	0.0
Warehouse Facility V [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	0.0	0.0
Average outstanding balance	0.0	0.0
Warehouse Facility VI [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	0.0	0.0
Average outstanding balance	0.0	0.0
Warehouse Facility VIII [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	0.0	0.0
Average outstanding balance	$ 0.0	$ 0.0