Note 7 - Investments in Privately-Held Raw Material Companies (Details Textual)			1 Months Ended										3 Months Ended				6 Months Ended			12 Months Ended
		Jan. 25, 2021 USD ($)	May 31, 2025 USD ($)	Apr. 30, 2025 USD ($)	Nov. 30, 2024 USD ($)	May 31, 2024 USD ($)	Nov. 30, 2023 USD ($)	May 31, 2023 USD ($)	Apr. 30, 2023 USD ($)	Jul. 31, 2022 USD ($)	Jun. 30, 2022 USD ($)	Jan. 31, 2021 USD ($)	Jun. 30, 2025 USD ($)		Jun. 30, 2024 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2025 USD ($)		Jun. 30, 2024 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2024 USD ($)	Apr. 30, 2022
Equity Method Investment, Other-than-Temporary Impairment													$ 0		$ 0		$ 0		$ 0
Equity Method Investments													14,330,000				14,330,000				$ 14,066,000
Income (Loss) from Equity Method Investments													(171,000)		598,000		77,000		1,488,000
Other Assets [Member]
Equity Method Investments													14,300,000				14,300,000				14,100,000
Jia Mei Investment [Member]
Percentage of Equity Method Investment Interest Sold								15.00%
Equity Method Investment, Ownership Percentage									25.00%
Proceeds from Sale of Equity Method Investments								$ 827,000
Equity Method Investment, Other-than-Temporary Impairment			$ 145,000
Jia Mei Investment [Member] | Other Assets [Member]
Equity Method Investments													406,000				406,000
Nonconsolidated Investees, Other [Member] | Other Assets [Member]
Equity Method Investments													$ 14,700,000				$ 14,700,000				14,600,000
Chaoyang Kaimei Quartz Co [Member]
Equity Method Investment, Ownership Percentage													40.00%	[1]			40.00%	[1]				40.00%
Equity Method Investments													$ 4,638,000				$ 4,638,000				3,895,000
Beijing Jiya [Member]
Equity Method Investment, Ownership Percentage													39.00%				39.00%
Equity Method Investments													$ 4,177,000				$ 4,177,000				4,867,000
Proceeds from Dividends Received				$ 900,000	$ 300,000		$ 500,000		$ 2,000,000
Xiaoyi Xingan Gallium [Member]
Equity Method Investment, Ownership Percentage	[2]												25.00%				25.00%
Equity Method Investments													$ 5,515,000				$ 5,515,000				$ 5,304,000
Proceeds from Dividends Received						$ 2,100,000	$ 1,800,000			$ 1,500,000
Beijing Bouy Vessel [Member]
Proceeds from Dividends Received											$ 1,300,000
Five Minority Investments [Member]
Income (Loss) from Equity Method Investments													$ 200,000		$ 600,000		$ 200,000		$ 1,500,000
Investor One [Member] | Jia Mei Investment [Member]
Payments to Acquire Investments			$ 360,000
Investor One [Member] | Jai Mei [Member]
Equity Method Investment, Ownership Percentage			8.90%
Investor Two [Member] | Jia Mei Investment [Member]
Payments to Acquire Investments			$ 360,000
Investor Two [Member] | Jai Mei [Member]
Equity Method Investment, Ownership Percentage			8.90%
Beijing Bouy Vessel [Member]
Subsidiary, Ownership Percentage, Noncontrolling Owner																33.00%				33.00%
Beijing Bouy Vessel [Member] | Beijing Bouy Vessel [Member]
Percentage of Equity Issued on Conversion of Non Controlling Interests																				7.59%
Nanjing Jin Mei Gallium [Member]
Subsidiary, Ownership Percentage, Noncontrolling Owner																8.50%				8.50%
Nanjing Jin Mei Gallium [Member] | Nanjing Jin Mei Gallium [Member]
Percentage of Equity Issued on Conversion of Non Controlling Interests																				0.38%
Beijing Tongmei Xtal Technology [Member]
Subsidiary, Ownership Percentage, Noncontrolling Owner		7.28%											14.50%				14.50%
Percentage of Equity Issued on Conversion of Non Controlling Interests		7.28%															14.50%			7.59%
Percentage of Equity Purchased by Employees, Key Managers, and Contributors																				0.40%
Capital Received From Private Equity Funds												$ 1,500,000				$ 48,100,000				$ 48,100,000
Capital Received, Approved		$ 49,000,000
Beijing Tongmei Xtal Technology [Member] | Nanjing Jin Mei Gallium [Member]
Percentage of Equity Issued on Conversion of Non Controlling Interests																				0.38%
Jai Mei [Member]
Subsidiary, Ownership Percentage, Noncontrolling Owner			10.00%					10.00%
Number of Investors			2
Jia Mei Investment [Member]
Subsidiary, Ownership Percentage, Noncontrolling Owner								10.00%					10.00%	[3]			10.00%	[3]

[1] In April 2022, Tongmei signed a joint venture agreement with certain investors to fund a new company, ChaoYang KaiMei.

[2] In preparation for Tongmei’s application for a listing of shares in an IPO on the STAR Market, in late December 2020 we reorganized our entity structures in China. JinMei and BoYu and their subsidiaries, previously organized under AXT, Inc., were assigned to Tongmei and effectively merged with Tongmei although they retained their own respective legal entity status and are wholly owned subsidiaries of Tongmei. The 33% minority interest stakeholders of BoYu converted their ownership to a 7.59% minority interest in Tongmei. The 8.5% minority interest stakeholders, employees of JinMei, converted their ownership to a 0.38% minority interest in Tongmei. Further, a number of employees, key managers and contributors, purchased a 0.4% minority interest in Tongmei. In 2020, the Investors transferred approximately $48.1 million of new capital to Tongmei. An additional investment of approximately $1.5 million of new capital was funded in early January 2021. Under China regulations these investments must be formally approved by the appropriate government agency and are not deemed to be dilutive until such approval is granted. The government approved the approximately $49 million investment in its entirety on January 25, 2021 at which time the Investors owned a redeemable noncontrolling interest in Tongmei of 7.28%. As of June 30, 2025, Tongmei’s noncontrolling interests and redeemable noncontrolling interests totaled approximately 14.5%. AXT remains the controlling stakeholder of Tongmei and holds a majority of the Board of Director positions of Tongmei.

[3] In May 2023, we sold 15% of our equity investments in Jia Mei to a third party. We now own 10% of Jia Mei and account for it under the fair value method.