Loans to Bank Customers - Loan Summary (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 2,283	$ 4,204
Total Current or Less Than 30 Days Past Due	18,782	18,379
Total Outstanding	$ 21,065	$ 22,583
Past Due (as a percent)	10.80%	18.60%
Total Current or Less Than 30 Days Past Due (as a percent)	89.20%	81.40%
Total Outstanding (as a percent)	100.00%	100.00%
30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 862	$ 1,082
Past Due (as a percent)	4.10%	4.80%
60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 600	$ 939
Past Due (as a percent)	2.90%	4.20%
90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 821	$ 2,183
Past Due (as a percent)	3.90%	9.70%
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 0	$ 1
Total Current or Less Than 30 Days Past Due	3,821	4,530
Total Outstanding	3,821	4,531
Residential | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	1
Residential | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Residential | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Total Current or Less Than 30 Days Past Due	1,901	158
Total Outstanding	1,901	158
Commercial | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Commercial | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Commercial | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	3	1
Total Current or Less Than 30 Days Past Due	591	1,246
Total Outstanding	594	1,247
Installment | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	1
Installment | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	3	0
Installment | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Secured credit card
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	2,280	4,202
Total Current or Less Than 30 Days Past Due	12,469	12,445
Total Outstanding	14,749	16,647
Secured credit card | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	862	1,080
Secured credit card | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	597	939
Secured credit card | 90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 821	$ 2,183