Debt (Summary Of Additional Information Of Credit facilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revolving Secured Line Of Credit [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	$ 229.0	$ 296.6
Average outstanding balance	29.1	108.3
Warehouse Facility II [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	201.0	201.0
Average outstanding balance	18.8	106.7
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	75.0
Average outstanding balance	0.0	19.1
Warehouse Facility VI [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	0.0	50.0
Average outstanding balance	0.0	18.0
Warehouse Facility VII [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	0.0	125.0
Average outstanding balance	0.0	61.9
Warehouse Facility VIII [Member]
Debt Instrument [Line Items]
Maximum outstanding balance	0.0	149.0
Average outstanding balance	$ 0.0	$ 28.2