Member Receivables, Net - Summary of Allowance for Credit Losses (Detail) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Financing Receivable, Allowance for Credit Loss, Writeoff, after Recovery [Abstract] | ||||
| Beginning balance | $ 37,641 | $ 22,703 | ||
| Plus: provision for credit losses | $ 36,549 | $ 29,846 | 91,953 | 65,744 |
| Plus: amounts recovered | 15,435 | 12,206 | ||
| Less: amounts written-off | (93,251) | (60,436) | ||
| Ending allowance balance at September 30, 2026, including Coastal-held ExtraCash receivables | 51,778 | |||
| Less: off -balance sheet allowance (included in other current liabilities) | (6,432) | |||
| Ending balance | $ 45,346 | $ 40,217 | $ 45,346 | $ 40,217 |