| Line Item | Jun 30, 2026 | Mar 31, 2026 | Dec 31, 2025 | Sep 30, 2025 | Jun 30, 2025 | Mar 31, 2025 | Dec 31, 2024 | Sep 30, 2024 | Jun 30, 2024 | Mar 31, 2024 | Dec 31, 2023 | Sep 30, 2023 | Jun 30, 2023 | Mar 31, 2023 | Dec 31, 2022 | Sep 30, 2022 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Operating revenues: | ||||||||||||||||
| Operating revenues | ||||||||||||||||
| Interest income, net | ||||||||||||||||
| Total operating revenues | ||||||||||||||||
| YoY growth | +18.2% | +17.4% | +14.9% | +20.8% | ||||||||||||
| Operating expenses: | ||||||||||||||||
| Sales and marketing expenses | ||||||||||||||||
| Compensation and benefits expenses | ||||||||||||||||
| Processing expenses | ||||||||||||||||
| Other general and administrative expenses | ||||||||||||||||
| Restructuring and other charges | ||||||||||||||||
| Total operating expenses | ||||||||||||||||
| % of revenue | 100.1% | 89.5% | 105.3% | 106.6% | ||||||||||||
| Operating (loss) income | ||||||||||||||||
| % of revenue | -0.1% | 10.5% | -5.3% | -6.6% | ||||||||||||
| Interest expense, net | ||||||||||||||||
| Other (expense) income, net | ||||||||||||||||
| (Loss) income before income taxes | ||||||||||||||||
| Income tax (benefit) expense | ||||||||||||||||
| Net (loss) income | ||||||||||||||||
| % of revenue | -0.4% | 8.2% | -9.0% | -6.2% | ||||||||||||
| Basic (loss) earnings per common share (in USD per share) | ||||||||||||||||
| Diluted (loss) earnings per common share (in USD per share) |