Note 12 - Commitments and Contingencies 2 (Details Textual) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Location, Statement of Financial Position, Balance [Axis]: ater:AccruedExpensesAndOtherLiabilitiesCurrent | ||
| Loss Contingency, Accrual, Current | $ 0.1 | $ 0.4 |