Loans Receivable (Summary of Changes in Accretable Yield) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019		Jun. 30, 2020	Jun. 30, 2019
Certain Loans Acquired in Transfer Not Accounted for as Loans Accretable Yield Movement Schedule [Roll Forward]
Balance, beginning of period			$ 2,226.2			$ 2,065.5
New Consumer Loan assignments			388.7	[1]		840.0
Accretion			(343.7)	[2]		(667.8)	[3]
Provision for credit losses			15.4			29.9
Forecast changes	$ 24.4	$ (206.5)	13.0		$ (182.1)	29.7
Transfers			(2.7)	[4]		(5.0)	[5]
Balance, end of period			2,302.3			2,302.3
Dealer Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Loans Accretable Yield Movement Schedule [Roll Forward]
Balance, beginning of period			1,361.2			1,283.0
New Consumer Loan assignments			244.6	[1]		535.9
Accretion			(224.8)	[2]		(440.5)	[3]
Provision for credit losses			14.5			26.1
Forecast changes	(0.1)		3.4		(76.0)	3.9
Transfers			(8.5)	[4]		(18.0)	[5]
Balance, end of period			1,390.4			1,390.4
Purchased Loans [Member]
Certain Loans Acquired in Transfer Not Accounted for as Loans Accretable Yield Movement Schedule [Roll Forward]
Balance, beginning of period			865.0			782.5
New Consumer Loan assignments			144.1	[1]		304.1
Accretion			(118.9)	[2]		(227.3)	[3]
Provision for credit losses			0.9			3.8
Forecast changes	$ 24.5		9.6		$ (106.1)	25.8
Transfers			(11.2)	[4]		(23.0)	[5]
Balance, end of period			$ 911.9			$ 911.9

[1] The Dealer Loans amount represents the net cash flows expected at the time of assignment on Consumer Loans assigned under our Portfolio Program, less the related advances paid to Dealers. The Purchased Loans amount represents the net cash flows expected at the time of assignment on Consumer Loans assigned under our Purchase Program, less the related one-time payments made to Dealers.

[2] Represents finance charges excluding the amortization of deferred direct origination costs for Dealer Loans.

[3] The Dealer Loans amount represents repayments that we collected on Consumer Loans assigned under our Portfolio Program, less the Dealer Holdback and Accelerated Dealer Holdback payments that we made. Purchased Loans amount represents repayments that we collected on Consumer Loans assigned under our Purchase Program.

[4] Under our Portfolio Program, certain events may result in Dealers forfeiting their rights to Dealer Holdback. We transfer the Dealer’s outstanding Dealer Loan balance, the related allowance for credit losses balance and related expected future net cash flows to Purchased Loans in the period this forfeiture occurs.

[5] Under our Portfolio Program, certain events may result in Dealers forfeiting their rights to Dealer Holdback. We transfer the Dealer’s outstanding Dealer Loan balance, related allowance for credit losses balance and related expected future net cash flows to Purchased Loans in the period this forfeiture occurs.