Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash Flows From Operating Activities:
Net income	$ 145.7	$ 119.2
Adjustments to reconcile cash provided by operating activities:
Provision for credit losses	14.6	9.3
Depreciation	2.9	2.5
Amortization	4.1	3.7
Loss on retirement of property and equipment	0.2	0.1
Provision for deferred income taxes	15.2	30.1
Loss on extinguishment of debt	0.0	21.8
Stock-based compensation	6.7	7.8
Change in operating assets and liabilities:
Increase (decrease) in accounts payable and accrued liabilities	11.2	(3.7)
Increase in income taxes receivable	(9.3)	(0.5)
Decrease in income taxes payable	(2.9)	(17.2)
Decrease in other assets	1.1	1.2
Net cash provided by operating activities	189.5	174.3
Cash Flows From Investing Activities:
Increase in restricted cash and cash equivalents	(19.9)	(45.3)
Purchases of restricted securities available for sale	(20.1)	(47.1)
Proceeds from sale of restricted securities available for sale	18.6	9.0
Maturities of restricted securities available for sale	2.4	37.2
Principal collected on Loans receivable	886.6	789.9
Advances to Dealers	(943.6)	(760.7)
Purchases of Consumer Loans	(174.2)	(94.0)
Accelerated payments of Dealer Holdback	(26.6)	(21.9)
Payments of Dealer Holdback	(78.6)	(67.8)
Purchases of property and equipment	(2.2)	(3.3)
Net cash used in investing activities	(357.6)	(204.0)
Cash Flows From Financing Activities:
Borrowings under revolving secured line of credit	1,123.1	1,347.0
Repayments under revolving secured line of credit	(1,217.8)	(1,343.6)
Proceeds from secured financing	571.4	921.6
Repayments of secured financing	(559.4)	(608.7)
Proceeds from issuance of senior notes	248.2	300.0
Repayment of senior notes	0.0	(350.0)
Payments of debt issuance and debt extinguishment costs	(8.1)	(25.8)
Repurchase of common stock	(1.1)	(218.7)
Proceeds from stock options exercised	0.0	0.6
Tax benefits from stock-based compensation plans	0.3	13.6
Proceeds from (Payments for) Other Financing Activities	6.4	(3.8)
Net cash provided by financing activities	163.0	32.2
Net increase (decrease) in cash and cash equivalents	(5.1)	2.5
Cash and cash equivalents, beginning of period	6.4
Cash and cash equivalents, end of period	1.3
Supplemental Disclosure of Cash Flow Information:
Cash paid during the period for interest	25.7	30.8
Cash paid during the period for income taxes	$ 79.9	$ 43.5