Debt (Schedule Of Outstanding Debt Amount) (Details) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Revolving secured line of credit principal balance outstanding		$ 79.2	$ 30.9
Secured Financings Principal balance outstanding		3,990.9	3,756.4
Senior notes principal balance outstanding		989.0	794.5
Mortgage note principal outstanding balance	[1]	8.4	8.9
Restricted cash and cash equivalents pledged as collateral		457.7	410.0	$ 410.9
Revolving Secured Line Of Credit [Member]
Debt Instrument [Line Items]
Revolving secured line of credit principal balance outstanding		79.2	30.9
Amount available for borrowing	[2]	$ 330.8	$ 379.1
Interest rate		7.33%	6.25%
Warehouse Facility II [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 0.0	$ 0.0
Loans pledged as collateral		0.0	0.0
Restricted cash and cash equivalents pledged as collateral		1.0	1.0
Amount available for borrowing	[2]	$ 400.0	$ 400.0
Interest rate		0.00%	0.00%
Warehouse Facility IV [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding			$ 0.0
Loans pledged as collateral		$ 0.0	0.0
Restricted cash and cash equivalents pledged as collateral		1.5	1.0
Amount available for borrowing	[2]	$ 300.0	$ 300.0
Interest rate		0.00%	0.00%
Warehouse Facility V [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 0.0
Loans pledged as collateral		0.0	$ 0.0
Restricted cash and cash equivalents pledged as collateral		1.0	1.0
Amount available for borrowing	[2]	$ 200.0	$ 200.0
Interest rate		0.00%	0.00%
Warehouse Facility VI [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 0.0	$ 0.0
Loans pledged as collateral		0.0	0.0
Restricted cash and cash equivalents pledged as collateral		0.0	0.0
Amount available for borrowing	[2]	$ 75.0	$ 75.0
Interest rate		0.00%	0.00%
Warehouse Facility VIII [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 0.0	$ 0.0
Loans pledged as collateral		0.0	0.0
Restricted cash and cash equivalents pledged as collateral		0.8	0.0
Amount available for borrowing	[2]	$ 200.0	$ 200.0
Interest rate		0.00%	0.00%
Term ABS 2019-2 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 500.0	$ 500.0
Loans pledged as collateral		597.3	627.5
Restricted cash and cash equivalents pledged as collateral		$ 47.6	$ 51.0
Interest rate		5.15%	5.15%
Term ABS 2019-3 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 0.0	$ 64.4
Loans pledged as collateral		0.0	200.9
Restricted cash and cash equivalents pledged as collateral		$ 0.0	$ 24.5
Interest rate		0.00%	3.00%
Term ABS 2020-1 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 0.0	$ 144.6
Loans pledged as collateral		0.0	362.5
Restricted cash and cash equivalents pledged as collateral		$ 0.0	$ 38.8
Interest rate		0.00%	2.51%
Term ABS 2020-2 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 0.0	$ 307.0
Loans pledged as collateral		0.0	452.0
Restricted cash and cash equivalents pledged as collateral		$ 0.0	$ 43.9
Interest rate		0.00%	1.81%
Term ABS 2020-3 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 110.3	$ 520.7
Loans pledged as collateral		418.4	655.1
Restricted cash and cash equivalents pledged as collateral		$ 42.3	$ 53.9
Interest rate		2.06%	1.47%
Term ABS 2021-1 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 100.0	$ 100.0
Loans pledged as collateral		112.8	115.0
Restricted cash and cash equivalents pledged as collateral		$ 8.8	$ 8.5
Interest rate		7.56%	6.52%
Term ABS 2021-2 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 188.2	$ 500.0
Loans pledged as collateral		415.5	572.9
Restricted cash and cash equivalents pledged as collateral		$ 37.3	$ 44.5
Interest rate		1.38%	1.12%
Term ABS 2021-3 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 265.0	$ 450.0
Loans pledged as collateral		396.3	519.9
Restricted cash and cash equivalents pledged as collateral		$ 33.8	$ 38.8
Interest rate		1.24%	1.14%
Term ABS 2021-4 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 221.6	$ 250.1
Loans pledged as collateral		255.2	278.5
Restricted cash and cash equivalents pledged as collateral		$ 21.0	$ 21.8
Interest rate		1.46%	1.44%
Term ABS 2022-1 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 350.0	$ 350.0
Loans pledged as collateral		378.2	434.7
Restricted cash and cash equivalents pledged as collateral		$ 27.4	$ 27.7
Interest rate		5.03%	5.03%
Term ABS 2022-2 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 200.0	$ 200.0
Loans pledged as collateral		212.1	229.3
Restricted cash and cash equivalents pledged as collateral		$ 14.7	$ 25.6
Interest rate		7.66%	6.65%
Term ABS 2022-3 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 389.9	$ 389.9
Loans pledged as collateral		418.9	429.2
Restricted cash and cash equivalents pledged as collateral		$ 28.9	$ 27.6
Interest rate		7.68%	7.68%
Term ABS 2023-1 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 400.0
Loans pledged as collateral		611.6	$ 0.0
Restricted cash and cash equivalents pledged as collateral		$ 38.5
Interest rate		6.92%
Term ABS 2023-2 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 400.0
Loans pledged as collateral		701.7	0.0
Restricted cash and cash equivalents pledged as collateral		$ 42.0
Interest rate		6.39%
Term ABS 2023-3 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 400.0
Loans pledged as collateral		643.8	0.0
Restricted cash and cash equivalents pledged as collateral		$ 40.3
Interest rate		6.86%
Term ABS 2023-A [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 200.0
Loans pledged as collateral		273.4	0.0
Restricted cash and cash equivalents pledged as collateral		$ 17.2
Interest rate		7.51%
Term ABS 2023-5 [Member]
Debt Instrument [Line Items]
Secured Financings Principal balance outstanding		$ 294.0
Loans pledged as collateral		433.9	0.0
Restricted cash and cash equivalents pledged as collateral		$ 52.2
Interest rate		6.54%
2024 Senior Notes [Member]
Debt Instrument [Line Items]
Senior notes principal balance outstanding		$ 0.0	$ 400.0
Interest rate		0.00%	5.125%
2026 Senior Notes [Member]
Debt Instrument [Line Items]
Senior notes principal balance outstanding		$ 400.0	$ 400.0
Interest rate		6.625%	6.625%
2028 Senior Notes [Member]
Debt Instrument [Line Items]
Senior notes principal balance outstanding		$ 600.0	$ 0.0
Interest rate		9.25%	0.00%
Mortgage [Member]
Debt Instrument [Line Items]
Mortgage note principal outstanding balance		$ 8.4	$ 8.9
Interest rate		6.88%	5.46%

[1] Measured at amortized cost with fair value disclosed.

[2] (1) Availability may be limited by the amount of assets pledged as collateral.