Note 7 - Income Taxes (Details Textual) - USD ($)	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Unrecognized Tax Benefits, Decrease Resulting from Foreign Taxes	$ 31,000	$ 71,000

Amount of decrease in unrecognized tax benefits resulting from foreign taxes.

No definition available.

Name:	ams_UnrecognizedTaxBenefitsDecreaseResultingFromForeignTaxes
Namespace Prefix:	ams_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration