Finance Receivables, net (Rollforward) (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2020	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Receivables [Abstract]
Amortized cost	$ 0
Initial negative allowance for expected recoveries	3,332,748	$ 3,351,532	$ 3,514,165	$ 3,514,165
Balance at end of period	$ 3,332,748
Beneficial interest, percentage of balance	1.00%

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant