Segment Reporting - Balance Sheet Data (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Segment Reporting
Total assets	$ 213,749	$ 207,204
U.S. Debit and Credit
Segment Reporting
Total assets	174,139	169,567
U.S. Prepaid Debit
Segment Reporting
Total assets	30,432	25,117
Other
Segment Reporting
Total assets	$ 9,178	$ 12,520