Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash Flows From Operating Activities:
Net income	$ 64.3	$ 99.5
Adjustments to reconcile cash provided by operating activities:
Provision for credit losses	186.0	137.4
Depreciation	2.2	2.2
Amortization	4.9	4.2
Provision for deferred income taxes	31.9	24.2
Stock-based compensation	10.9	9.9
Other	0.4	0.3
Change in operating assets and liabilities:
Increase (decrease) in accounts payable and accrued liabilities	16.6	(6.0)
Increase in income taxes receivable	(6.8)	(2.3)
Decrease in income taxes payable	(11.5)	(0.2)
Decrease in other assets	11.1	27.3
Net cash provided by operating activities	310.0	296.5
Payments to Acquire Debt Securities, Available-for-sale	21.7	11.4
Cash Flows From Investing Activities:
Proceeds from sale of restricted securities available for sale	12.9	5.6
Maturities of restricted securities available for sale	1.5	2.5
Principal collected on Loans receivable	820.7	823.3
Advances to Dealers	(1,009.4)	(745.9)
Purchases of Consumer Loans	(307.6)	(349.4)
Accelerated payments of Dealer Holdback	(15.1)	(10.8)
Payments of Dealer Holdback	(64.9)	(57.2)
Purchases of property and equipment	(0.3)	(0.9)
Net cash used in investing activities	(583.9)	(344.2)
Cash Flows From Financing Activities:
Borrowings under revolving secured lines of credit	2,042.0	1,522.3
Repayments under revolving secured lines of credit	(1,951.7)	(1,408.1)
Proceeds from secured financing	1,062.8	601.0
Repayments of secured financing	(607.3)	(585.5)
Payments of debt issuance costs	(6.3)	(3.4)
Repurchase of common stock	(191.1)	(14.9)
Proceeds from Issuance of Common Stock	14.6	4.1
Other	7.6	2.6
Net cash provided by financing activities	370.6	118.1
Net increase in cash and cash equivalents and restricted cash and cash equivalents	96.7	70.4
Cash and cash equivalents and restricted cash and cash equivalents beginning of period	470.9	417.7
Cash and cash equivalents and restricted cash and cash equivalents end of period	567.6	488.1
Supplemental Disclosure of Cash Flow Information:
Cash paid during the period for interest	77.9	50.6
Cash paid during the period for income taxes, net of refunds	$ 5.2	$ 3.4