The Company and Summary of Significant Accounting Policies - Principles of Consolidation (Details)		1 Months Ended									12 Months Ended
	Jan. 25, 2021 USD ($)	Aug. 31, 2022 USD ($)	Jul. 31, 2022 USD ($)	May 31, 2022 USD ($)	Apr. 30, 2022 USD ($)	Jan. 31, 2022 USD ($)	Jun. 30, 2021 USD ($)	May 31, 2021 USD ($)	Feb. 28, 2021 USD ($)	Jan. 31, 2021 USD ($)	Dec. 31, 2022 USD ($) company	Dec. 31, 2021 USD ($) company	Dec. 31, 2020 USD ($)	Sep. 30, 2022	Oct. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of equity method investments | company											6	5
Investments, equity method											$ 14,607,000	$ 10,166,000
Transaction results in increase to redeemable noncontrolling interests												1,241,000
Sale of subsidiary shares to noncontrolling interests												1,151,000	$ 396,000
Increase in redeemable noncontrolling interests												1,514,000
Foreign Currency Translation
Foreign exchange gain (loss)											1,573,000	(434,000)	$ (411,000)
AXT-Tongmei, Inc | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Cash consideration							$ 1,000,000
Chao Yang XinMei High Purity Semiconductor Materials Co. Ltd. | Loan from related party
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Increase in redeemable noncontrolling interests				$ 100,000
Chao Yang XinMei High Purity Semiconductor Materials Co. Ltd. | Loan from related party | ChaoYang Xinshuo
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Loan amount															$ 1,000,000.0	$ 900,000
Sale of subsidiary shares to noncontrolling interests					$ 1,900,000
Amount paid to subsidiary				600,000	700,000
Chao Yang XinMei High Purity Semiconductor Materials Co. Ltd. | Loan from related party | Beijing Tongmei Xtal Technology
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Sale of subsidiary shares to noncontrolling interests					2,600,000
Amount paid to subsidiary				800,000	1,100,000
Increase in noncontrolling interest				$ 1,400,000		$ 2,200,000
Increase in redeemable noncontrolling interests						$ 200,000
Chao Yang XinMei High Purity Semiconductor Materials Co. Ltd.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Investment value, agreement amount								$ 1,800,000	$ 3,000,000.0
Investments, equity method									$ 1,800,000
Ownership (as a percent)			58.50%	58.50%		58.50%		58.50%	58.50%
Initial funding								$ 1,500,000	$ 1,500,000
Increase in noncontrolling interest			$ 610,000
Further investment			600,000
Redeemable noncontrolling interest increased			57,000
Chao Yang XinMei High Purity Semiconductor Materials Co. Ltd. | Loan from related party
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Sale of subsidiary shares to noncontrolling interests					4,500,000
ChaoYang ShuoMei High Purity Semiconductor Materials Co., Ltd.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Investment value, agreement amount					4,400,000
Investments, equity method					$ 3,300,000
Ownership (as a percent)					75.00%
Initial funding		$ 334,000
Increase in noncontrolling interest		406,000
Redeemable noncontrolling interest increased		73,000
ChaoYang KaiMei Quartz Co., Ltd
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Investment value, agreement amount					$ 7,600,000
Investments, equity method					$ 3,000,000.0						$ 827,000
Ownership (as a percent)					40.00%						40.00%
Initial funding			2,200,000
Investment amount			900,000
Beijing BoYu Semiconductor Vessel Craftwork Technology Co., Ltd Investment
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Percentage of outstanding shares													33.00%
Beijing BoYu Semiconductor Vessel Craftwork Technology Co., Ltd Investment | Beijing Boyu Semiconductor Vessel Craftwork Technology Co Ltd
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Private equity ownership percentage													7.59%
Beijing Tongmei Xtal Technology
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Percentage of outstanding shares	7.28%													14.50%
Private equity ownership percentage	7.28%										14.50%
Percentage of key managers and contributors purchased													0.40%
Investment in new facility	$ 49,000,000												$ 48,100,000
Raised additional capital												1,500,000
Transaction results in increase to noncontrolling interests							1,200,000
Transaction results in increase to redeemable noncontrolling interests							$ 1,200,000
Increase in redeemable noncontrolling interests										$ 1,500,000			$ 48,100,000
Beijing Tongmei Xtal Technology | Beijing Boyu Semiconductor Vessel Craftwork Technology Co Ltd
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Investment amount									$ 900,000
Private equity ownership percentage													7.59%
Beijing Tongmei Xtal Technology | Nanjing JinMei Gallium Co., Ltd
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Private equity ownership percentage													0.0038%
Beijing Tongmei Xtal Technology | Chao Yang XinMei High Purity Semiconductor Materials Co. Ltd.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Loan amount						$ 1,400,000						$ 1,400,000
Beijing Tongmei Xtal Technology | Chao Yang XinMei High Purity Semiconductor Materials Co. Ltd. | Loan from related party
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Increase in noncontrolling interest				$ 1,400,000
Beijing Tongmei Xtal Technology | Chao Yang XinMei High Purity Semiconductor Materials Co. Ltd.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Initial funding			800,000
Investment amount								$ 900,000
Further investment			$ 800,000
Nanjing JinMei Gallium Co., Ltd Investment
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Percentage of outstanding shares													8.50%
Nanjing JinMei Gallium Co., Ltd Investment | Nanjing JinMei Gallium Co., Ltd
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Private equity ownership percentage													0.38%
Chao Yang XinMei High Purity Semiconductor Materials Co. Ltd. | ChaoYang ShuoMei High Purity Semiconductor Materials Co., Ltd.
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Initial funding		$ 1,000,000.0