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Debt (Summary Of Additional Information Of Credit facilities) (Details) - USD ($) $ in Millions | 12 Months Ended
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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

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