Finance Receivables, net (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Changes in estimated recoveries	$ 25,403	$ 0	$ 32,388	$ 0
Face value of receivable portfolios		2,400,000		8,900,000
Payments to acquire finance receivables		279,000		887,000
Estimated remaining collections on purchased receivables		494,800		1,400,000
Unamortized purchased principal (purchase price) under the cost recovery method		$ 36,200		$ 36,200
Financing Receivable, Allowance For Credit Loss, Changes In Expected Future Recoveries	(63,587)		(183,911)
Financing Receivable, Allowance For Credit Loss, Recoveries In Excess (Shortfall) Of Forecast	$ 88,990		$ 216,299