Accounts Receivable - Accounts Receivable, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable current and noncurrent, net	$ 44,175		$ 59,543
Trade receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross	15,896		14,512
Reserve for uncollectible overdrawn accounts	(259)		(202)
Accounts receivable current and noncurrent, net	15,637		14,310
Overdrawn cardholder balances from purchase transactions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross	3,270		4,327
Reserve for uncollectible overdrawn accounts	(2,175)	$ (5,070)	(3,398)	$ (3,119)	$ (2,368)	$ (2,710)
Accounts receivable current and noncurrent, net	1,095		929
Overdrawn cardholder balances from maintenance fees
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable current and noncurrent, net	2,772		2,235
Total net overdrawn account balances due from cardholders
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable current and noncurrent, net	3,867		3,164
Receivables due from card issuing banks
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable current and noncurrent, net	5,577		5,758
Fee advances, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable current and noncurrent, net	3,179		26,268
Other receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable current and noncurrent, net	$ 15,915		$ 10,043