Net Income (Loss) Per Common Share Attributable to Alpha and Omega Semiconductor Limited - Potential Dilutive Shares (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	3,421	2,846	3,376	3,145
Employee stock options and RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	2,221	2,322	2,367	2,493
ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities (in shares)	1,200	524	1,009	652