Debt (Narrative) (Details)		12 Months Ended
		Dec. 31, 2023 USD ($) facility		Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
Maximum hedging reserve		$ 1,000,000
Senior notes		989,000,000.0		$ 794,500,000
Repayments of senior notes		400,000,000.0		0	$ 0
Loss on extinguishment of debt		$ 1,800,000		0	$ 0
Revolving Secured Line Of Credit [Member]
Debt Instrument [Line Items]
Debt maturity date		Jun. 22, 2026
Line of credit facility	[1]	$ 390,000,000
Percentage of net book value of loans		80.00%
Warehouse Facilities [Member]
Debt Instrument [Line Items]
Percentage of net book value of loans		80.00%
Number of warehouse facilities | facility		5
Debt financing amount		$ 1,175,000,000
Monthly servicing fee per financing		6.00%
Monthly Servicing Fee Per Financing on Newer Deals		4.00%
Warehouse Facility II [Member]
Debt Instrument [Line Items]
Debt maturity date	[2],[3]	Apr. 30, 2026
Debt financing amount		$ 400,000,000.0	[2],[4]	$ 400,000,000.0
Interest rate		0.00%		0.00%
Warehouse Facility IV [Member]
Debt Instrument [Line Items]
Debt maturity date	[2],[3]	Dec. 29, 2026
Debt financing amount		$ 300,000,000.0	[2],[4]	$ 300,000,000.0
Interest rate		0.00%		0.00%
Warehouse Facility V [Member]
Debt Instrument [Line Items]
Debt maturity date	[2],[5]	Dec. 29, 2025
Debt financing amount		$ 200,000,000.0	[2],[4]	$ 200,000,000.0
Interest rate		0.00%		0.00%
Warehouse Facility VI [Member]
Debt Instrument [Line Items]
Debt maturity date	[2],[3]	Sep. 30, 2026
Debt financing amount	[2]	$ 75,000,000.0
Interest rate		0.00%		0.00%
2024 Senior Notes [Member]
Debt Instrument [Line Items]
Senior notes		$ 0		$ 400,000,000.0
Interest rate		0.00%		5.125%
2026 Senior Notes [Member]
Debt Instrument [Line Items]
Debt maturity date		Mar. 15, 2026
Debt financing amount		$ 400,000,000.0
Senior notes		$ 400,000,000.0		$ 400,000,000.0
Interest rate		6.625%		6.625%
Mortgage [Member]
Debt Instrument [Line Items]
Debt maturity date	[2]	Aug. 06, 2028
Debt financing amount	[2]	$ 9,000,000
Interest rate		6.88%		5.46%
Warehouse Facility VIII [Member]
Debt Instrument [Line Items]
Debt maturity date	[2],[3]	Sep. 21, 2026
Debt financing amount		$ 200,000,000.0	[2],[4]	$ 200,000,000.0
Interest rate		0.00%		0.00%
Term ABS Financing [Member]
Debt Instrument [Line Items]
Monthly servicing fee per financing		6.00%
Monthly Servicing Fee Per Financing on Newer Deals		4.00%
Term ABS 2021-2 [Member]
Debt Instrument [Line Items]
Debt maturity date	[2],[3]	Feb. 15, 2023
Debt financing amount	[2]	$ 500,000,000.0
Interest rate		1.38%		1.12%
Term ABS 2021-3 [Member]
Debt Instrument [Line Items]
Debt maturity date	[2],[3]	May 15, 2023
Debt financing amount	[2]	$ 450,000,000.0
Interest rate		1.24%		1.14%
Term ABS 2021-4 [Member]
Debt Instrument [Line Items]
Debt maturity date	[2],[3]	Oct. 16, 2023
Debt financing amount	[2]	$ 250,100,000
Interest rate		1.46%		1.44%
Prime Rate [Member] | Revolving Secured Line Of Credit [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		87.50%
BSBY [Member] | Revolving Secured Line Of Credit [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		187.50%
BSBY [Member] | Warehouse Facility VI [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	[4]	200.00%
BSBY [Member] | Mortgage [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		150.00%

[1] Borrowings are subject to repayment on demand.

[2] Financing made available only to a specified subsidiary of the Company.

[3] Represents the revolving maturity date. The outstanding balance will amortize after the revolving maturity date based on the cash flows of the pledged assets.

[4] Interest rate cap agreements are in place to limit the exposure to increasing interest rates.

[5] Represents the revolving maturity date. The outstanding balance will amortize after the revolving maturity date and any amounts remaining on December 27, 2027 will be due on that date.