AXT (AXTI) 10-Q 8 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	1-May-15
Document and Entity Information [Abstract]
Entity Registrant Name	AXT INC
Entity Central Index Key	1051627
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		32,661,014
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$33,285	$28,814
Short-term investments	3,590	12,340
Accounts receivable, net of allowances of $1,049 and $823 as of March 31, 2015 and December 31, 2014	18,787	17,864
Inventories	39,475	38,574
Related party notes receivable - current	173	171
Prepaid expenses and other current assets	4,312	5,430
Total current assets	99,622	103,193
Long-term investments	10,612	7,783
Property, plant and equipment, net	33,223	33,862
Related party notes receivable - long-term	1,710	1,704
Other assets	15,128	14,975
Total assets	160,295	161,517
Current liabilities:
Accounts payable	9,131	7,137
Accrued liabilities	5,815	7,634
Total current liabilities	14,946	14,771
Long-term portion of royalty payments	1,581	1,725
Other long-term liabilities	350	333
Total liabilities	16,877	16,829
Commitments and contingencies (Note 11)
Stockholders' equity:
Preferred stock, $0.001 par value; 2,000 shares authorized; 883 shares issued and outstanding as of March 31, 2015 and December 31, 2014 (Liquidation preference of $6.3 million and $6.3 million as of March 31, 2015 and December 31, 2014.)	3,532	3,532
Common stock, $0.001 par value; 70,000 shares authorized; 32,661 and 32,837 shares issued and outstanding as of March 31, 2015 and December 31, 2014.	32	32
Additional paid-in capital	195,152	195,419
Accumulated deficit	-69,417	-68,393
Accumulated other comprehensive income	7,620	7,673
Total AXT, Inc. stockholders' equity	136,919	138,263
Noncontrolling interests	6,499	6,425
Total stockholders' equity	143,418	144,688
Total liabilities and stockholders' equity	$160,295	$161,517

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Share data in Thousands, except Per Share data, unless otherwise specified
Current assets:
Accounts receivable, allowances for doubtful accounts	$1,049,000	$823,000
Stockholders' equity:
Preferred stock, par value (in dollars per share)	$0.00	$0.00
Preferred stock, shares authorized (in shares)	2,000	2,000
Preferred stock, shares issued (in shares)	883	883
Preferred stock, shares outstanding (in shares)	883	883
Preferred stock, liquidation preference	$6,300,000	$6,300,000
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized (in shares)	70,000	70,000
Common stock, shares issued (in shares)	32,661	32,837
Common stock, shares outstanding (in shares)	32,661	32,837

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) [Abstract]
Revenue	$20,064	$19,345
Cost of revenue	15,315	16,627
Gross profit	4,749	2,718
Operating expenses:
Selling, general and administrative	5,251	3,436
Research and development	1,241	775
Restructuring charge	0	907
Total operating expenses	6,492	5,118
Loss from operations	-1,743	-2,400
Interest income, net	97	127
Equity in earnings of unconsolidated joint ventures	200	487
Other income, net	633	10
Loss before provision for income taxes	-813	-1,776
Provision for income taxes	86	59
Net loss	-899	-1,835
Less: Net income attributable to noncontrolling interests	-125	-205
Net loss attributable to AXT, Inc.	($1,024)	($2,040)
Net loss attributable to AXT, Inc. per common share:
Basic (in dollars per share)	($0.03)	($0.06)
Diluted (in dollars per share)	($0.03)	($0.06)
Weighted average number of common shares outstanding:
Basic (in shares)	32,553	32,364
Diluted (in shares)	32,553	32,364

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) [Abstract]
Net loss	($899)	($1,835)
Other comprehensive income (loss), net of tax:
Change in foreign currency translation gain (loss), net of tax	238	-521
Change in unrealized gain (loss) on available-for-sale investments, net of tax	-259	-10
Total other comprehensive loss, net of tax	-21	-531
Comprehensive loss	-920	-2,366
Less: Comprehensive income attributable to the noncontrolling interest	-157	-126
Comprehensive loss attributable to AXT, Inc.	($1,077)	($2,492)

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Cash flows from operating activities:
Net loss	($899)		($1,835)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,403		1,404
Amortization of marketable securities premium	55		122
Stock-based compensation	274		292
Loss (gain) on disposal of property, plant and equipment	9		-5
Provision for doubtful accounts	150		1
Realized gain on sale of investments	-367		0
Changes in assets and liabilities:
Accounts receivable, net	-1,052		-1,459
Inventories	-858		985
Prepaid expenses and other current assets	1,124		1,584
Other assets	-151		18
Accounts payable	1,979		-489
Accrued liabilities	-1,906	[1]	-697	[1]
Other long-term liabilities	-110		-308
Net cash used in operating activities	-349		-387
Cash flows from investing activities:
Purchases of property, plant and equipment	-676		-163
Proceeds from sales of property, plant and equipment	2		5
Purchases of available for sale securities	-4,304		-3,725
Proceeds from sales and maturities of available-for-sale securities	10,277		2,180
Net cash provided by (used in) investing activities	5,299		-1,703
Cash flows from financing activities:
Proceeds from common stock options exercised	76		0
Repurchase of the Company's common stock, including commission	-617		0
Net cash used in financing activities	-541		0
Effect of exchange rate changes on cash and cash equivalents	62		-111
Net increase (decrease) in cash and cash equivalents	4,471		-2,201
Cash and cash equivalents at the beginning of the period	28,814		24,961
Cash and cash equivalents at the end of the period	$33,285		$22,760
[1]	Dividends accrued but not paid by joint ventures of $646 and $729 was included in accrued liabilities as of March 31, 2015 and March 31, 2014, respectively.

CONDENSED_CONSOLIDATED_STATEME3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) [Abstract]
Dividends accrued but not paid by joint ventures	$646	$563	$729

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Basis of Presentation [Abstract]
Basis of Presentation	Note 1. Basis of Presentation
	The accompanying condensed consolidated financial statements of AXT, Inc. (“AXT,” the “Company,” “we,” “us,” and “our” refer to AXT, Inc. and all of its consolidated subsidiaries) are unaudited, and have been prepared in accordance with accounting principles generally accepted in the United States of America for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, the year-end condensed consolidated balance sheet data was derived from our audited consolidated financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America. In the opinion of our management, the unaudited condensed consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, considered necessary to present fairly the financial position, results of operations and cash flows of AXT and our consolidated subsidiaries for all periods presented.
	Our management has made a number of estimates and assumptions relating to the reporting of assets and liabilities and the disclosure of contingent assets and liabilities to prepare these condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States of America. Actual results could differ materially from those estimates.
	The results of operations are not necessarily indicative of the results to be expected in the future or for the full fiscal year. It is recommended that these condensed consolidated financial statements be read in conjunction with our consolidated financial statements and the notes thereto included in our 2014 Annual Report on Form 10-K filed with the Securities and Exchange Commission (the “SEC”) on March 13, 2015.
	The consolidated financial statements include the accounts of AXT, our wholly-owned subsidiary, Beijing Tongmei Xtal Technology Co., Ltd., and our majority-owned subsidiaries, Beijing JiYa Semiconductor Material Co., Ltd., Nanjing Jin Mei Gallium Co., Ltd. and Beijing BoYu Semiconductor Vessel Craftwork Technology Co., Ltd. All significant inter‑company accounts and transactions have been eliminated. Investments in business entities in which we do not have control, but have the ability to exercise significant influence over operating and financial policies (generally 20-50% ownership), are accounted for by the equity method. For majority-owned subsidiaries, we reflect the noncontrolling interest of the portion we do not own on our condensed consolidated balance sheets in stockholders’ equity and in our condensed consolidated statements of operations.

Investments_and_Fair_Value_Mea

Investments and Fair Value Measurements	3 Months Ended
	Mar. 31, 2015
Investments and Fair Value Measurements [Abstract]
Investments and Fair Value Measurements	Note 2. Investments and Fair Value Measurements
	Our cash and cash equivalents consist of cash and instruments with original maturities of less than 90 days. Our investments consist of instruments with original maturities of more than 90 days. As of March 31, 2015 and December 31, 2014, our cash, cash equivalents and investments are classified as follows (in thousands):
			March31,2015											December31,2014
			Amortized		Gross			Gross			Fair			Amortized		Gross			Gross			Fair
			Cost		Unrealized			Unrealized			Value			Cost		Unrealized			Unrealized			Value
					Gain			(Loss)								Gain			(Loss)
	Classified as:
	Cash		$	25,662	$	—		$	—		$	25,662		$	22,337	$	—		$	—		$	22,337
	Cash equivalents:
	Certificates of deposit1			7,623		—			—			7,623			6,454		—			—			6,454
	Money market fund			—		—			—			—			23		—			—			23
	Total cash and cash equivalents			33,285		—			—			33,285			28,814		—			—			28,814
	Investments (available for sale):
	Certificates of deposit2			6,425		1			(7	)		6,419			10,195		1			(13	)		10,183
	Corporate bonds			7,342		—			(31	)		7,311			9,214		1			(29	)		9,186
	Corporate equity security			24		448			—			472			44		710			—			754
	Total investments			13,791		449			(38	)		14,202			19,453		712			(42	)		20,123
	Total cash, cash equivalents and investments		$	47,076	$	449		$	(38	)	$	47,487		$	48,267	$	712		$	(42	)	$	48,937
	Contractual maturities on investments:
	Due within 1 year		$	3,144							$	3,590		$	11,631							$	12,340
	Due after 1 through 5 years			10,647								10,612			7,822								7,783
			$	13,791							$	14,202		$	19,453							$	20,123
	1	Certificate of deposit with original maturities of less than 90 days.
	2	Certificate of deposit with original maturities of more than 90 days.
	We manage our investments as a single portfolio of highly marketable securities that is intended to be available to meet our current cash requirements. We have no investments in auction rate securities. Certificates of Deposit and Corporate bonds are typically held until maturity. Corporate equity securities have no maturity and may be sold at any time. Our current holding of corporate equity securities consists of the common stock of Intelligent Epitaxy Technology, Inc (“IntelliEPI”), a Taiwan publicly-traded company. During the three months ended March 31, 2015, we sold some of our IntelliEpi stock. From this, our cash proceeds from sales of available-for-sale investments was $387,000. Our cost was $20,000 and our gross realized gain from sales of available-for-sale investments was $367,000.There were no sales of available-for-sale securities and no realized gains and losses for the three months ended March 31, 2014.
	We began classifying IntelliEpi stock as an available-for-sale security upon its initial public offering in 2013. An unrealized gain of $448,000 net of tax remains as of March 31, 2015 for IntelliEpi stock still held. These securities are valued at fair market value at March 31, 2015 and December 31, 2014. There is no assurance that we will realize this value when the securities are sold in the future.
	The gross unrealized losses related to our portfolio of available-for-sale securities were primarily due to changes in interest rates and market and credit conditions of the underlying securities. We have determined that the gross unrealized losses on some of our available-for-sale securities as of March 31, 2015 are temporary in nature. We periodically review our investment portfolio to identify and evaluate investments that have indications of possible impairment. Factors considered in determining whether a loss is temporary include the magnitude of the decline in market value, the length of time the market value has been below cost (or adjusted cost), credit quality, and our ability and intent to hold the securities for a period of time sufficient to allow for any anticipated recovery in market value.
	The following table summarizes the fair value and gross unrealized losses related to available-for-sale securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of March 31, 2015 (in thousands):
	As of March 31, 2015		InLossPosition					InLossPosition						TotalIn
			<12months					>12months						LossPosition
			Fair		Gross			Fair			Gross			Fair		Gross
			Value		Unrealized			Value			Unrealized			Value		Unrealized
					(Loss)						(Loss)					(Loss)
	Investments:
	Certificates of deposit		$	4,018	$	(7	)	$	480		$	—		$	4,498	$	(7	)
	Corporate bonds			7,311		(31	)		—			—			7,311		(31	)
	Total in loss position		$	11,329	$	(38	)	$	480		$	—		$	11,809	$	(38	)
	A portion of our investments would generate a loss if we sold them on March 31, 2015. The following table summarizes the fair value and gross unrealized losses related to available-for-sale securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of December 31, 2014 (in thousands):
	As of December 31, 2014		InLossPosition					InLossPosition						TotalIn
			<12months					>12months						LossPosition
			Fair		Gross			Fair			Gross			Fair		Gross
			Value		Unrealized			Value			Unrealized			Value		Unrealized
					(Loss)						(Loss)					(Loss)
	Investments:
	Certificates of deposit		$	4,492	$	(13	)	$	—		$	—		$	4,492	$	(13	)
	Corporate bonds			3,770		(27	)		4,309			(2	)		8,079		(29	)
	Total in loss position		$	8,262	$	(40	)	$	4,309		$	(2	)	$	12,571	$	(42	)
	Investments in Privately-held Companies
	We have made strategic investments in private companies located in China in order to gain access at a competitive cost to raw materials that are critical to our substrate business (see Note 6). The investment balances for all of these companies, including minority investments indirectly in privately-held companies made by our consolidated subsidiaries, accounted for under the equity method are included in “other assets” in the consolidated balance sheets and totaled $12.5 million and $12.1 million as of March 31, 2015 and December 31, 2014, respectively.
	We also maintain minority investments in one company which is accounted for under the cost method as we do not have the ability to exercise significant influence over their operations. Our investments under the cost method are reviewed for other than temporary declines in value on a quarterly basis. We monitor our investments for impairment and record reductions in carrying value when events or changes in circumstances indicate that the carrying value may not be recoverable. As of March 31, 2015 and December 31, 2014, our investments in this unconsolidated company had a carrying value of $200,000 and were also included in “other assets” in the condensed consolidated balance sheets.
	Fair Value Measurements
	ASC topic 820, Fair value measurement (“ASC 820”) establishes three levels of inputs that may be used to measure fair value. Level 1 instrument valuations are obtained from real-time quotes for transactions in active exchange markets of the asset or identical assets. Level 2 instrument valuations are obtained from readily-available pricing sources for comparable instruments. Level 3 instrument valuations are obtained from unobservable inputs in which there is little or no market data, which require us to develop our own assumptions. On a recurring basis, we measure certain financial assets and liabilities at fair value, primarily consisting of our short-term and long-term investments.
	The type of instrument valued based on quoted market prices in active markets include our money market funds, which are generally classified within Level 1 of the fair value hierarchy. Other than corporate equity securities which are based on quoted market prices and classified as Level 1, we classify our available-for-sale securities including certificates of deposit, corporate bonds as having Level 2 inputs. The valuation techniques used to measure the fair value of these financial instruments having Level 2 inputs were derived from quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency.
	We place short term foreign currency hedges that are intended to offset the potential cash exposure related to fluctuations in the exchange rate between the United States dollar and Japanese yen. We measure the fair value of these foreign currency hedges at each month end and quarter end using current exchange rates and in accordance with generally accepted accounting principles. At quarter end any foreign currency hedges not settled are netted in “accrued liabilities” on the consolidated balance sheet and classified as Level 3 assets and liabilities. As of March 31, 2015 the net change in fair value from the placement of the hedge to settlement at each month end during the quarter had a de minimis impact to the consolidated results.
	There were no changes in valuation techniques or related inputs in the three months ended March 31, 2015. There have been no transfers between fair value measurement levels during the three months ended March 31, 2015.
	The following table summarizes our financial assets and liabilities measured at fair value on a recurring basis in accordance with ASC 820 as of March 31, 2015 (in thousands):
			Balance as of		Quoted Prices in			Significant Other			Significant
			31-Mar-15		Active Markets of			Observable Inputs			Unobservable Inputs
					Identical Assets			(Level2)			(Level 3)
					(Level1)
	Assets:
	Cash equivalents and investments:
	Certificates of deposit		$	14,042	$	—		$	14,042		$	—
	Corporate bonds			7,311		—			7,311			—
Corporate equity securities			472		472			—			—
Total		$	21,825	$	472		$	21,353		$	—
Liabilities:
Foreign currency hedge obligations		$	2	$	—		$	—		$	2
The following table summarizes our financial assets and liabilities measured at fair value on a recurring basis in accordance with ASC 820 as of December 31, 2014 (in thousands):
		Balance as of		Quoted Prices in			Significant Other			Significant
		31-Dec-14		Active Markets of			Observable Inputs			Unobservable Inputs
				Identical Assets			(Level2)			(Level 3)
				(Level1)
Assets:
Cash equivalents and investments:
Money market fund		$	23	$	23		$	—		$	—
Certificates of deposit			10,183		—			10,183			—
Corporate bonds			9,186		—			9,186			—
Corporate equity securities			754		754			—			—
Total		$	20,146	$	777		$	19,369		$	—
Liabilities		$	—	$	—		$	—		$	—
Items Measured at Fair Value on a Nonrecurring Basis
Certain assets that are subject to nonrecurring fair value measurements are not included in the table above. These assets include investments in privately-held companies accounted for by equity and cost method (See Note 6). We did not record other-than-temporary impairment charges for either of these investments during the three months ended March 31, 2015 or 2014.

Inventories

Inventories	3 Months Ended
	Mar. 31, 2015
Inventories [Abstract]
Inventories	Note 3. Inventories
	The components of inventories are summarized below (in thousands):
		March31,		December31,
		2015		2014
	Inventories:
	Raw materials	$	19,688	$	18,990
	Work in process		16,948		16,222
	Finished goods		2,839		3,362
		$	39,475	$	38,574
	As of March 31, 2015 and December 31, 2014, carrying values of inventories were net of inventory reserve of $11.4 million and $11.2 million, respectively, for excess and obsolete inventory.

Accrued_Liabilities

Accrued Liabilities	3 Months Ended
	Mar. 31, 2015
Accrued Liabilities [Abstract]
Accrued Liabilities	Note 4. Accrued Liabilities
	The components of accrued liabilities are summarized below (in thousands):
		March31,		December31,
		2015		2014
	Accrued product warranty	$	392	$	802
	Accrued compensation and related charges		1,718		2,656
	Current portion of royalty payments		744		800
	Dividends payable by consolidated joint ventures		646		563
	Accrued professional services		304		509
	Accrued income taxes		110		119
	Other accrued liabilities		1,901		2,185
		$	5,815	$	7,634

Related_Party_Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2015
Related Party Transactions [Abstract]
Related Party Transactions	Note 5. Related Party Transactions
	In August 2011, our consolidated joint venture, Beijing JiYa Semiconductor Material Co., Ltd. (“JiYa”), entered into a non-interest bearing note agreement in the amount of $1.7 million for a loan to one of its equity investment entities.  The original term of the loan was for two years and ten months with 3 periodic principal payments required.  After various amendments to the terms of the note, in December 2013 the parties agreed to delay all principal repayment until December 2016. As of March 31, 2015, and December 31, 2014, we included $1.7 million in “Related party notes receivable – long term” in our condensed consolidated balance sheets.
	JiYa also purchases raw materials from one of its equity investment entities for production in the ordinary course of business. As of March 31, 2015 and December 31, 2014, amounts payable of $1.8 million were included in “accounts payable” in our condensed consolidated balance sheets.
	JiYa also sells raw materials to one of its equity investment entities for production in the ordinary course of business. As of March 31, 2015 and December 31, 2014, amounts receivable of $350,000 were included in “accounts receivable” in our condensed consolidated balance sheets.
	Beginning in 2012, our consolidated joint venture, Nanjing Jin Mei Gallium Co., Ltd. (“Jin Mei”), is contractually obligated under an agency sales agreement to sell raw material on behalf of its equity investment entity. Jin Mei bills the customers and remits the receipts, net of its portions of sales commission, to this equity investment entity. For the three months ended March 31, 2015 and 2014, Jin Mei has recorded $1,000 and $5,000 income from agency sales, respectively, which were included in “other income (expense), net” in the condensed consolidated statements of operations.
	In March 2012, our wholly-owned subsidiary, Beijing Tongmei Xtal Technology Co., Ltd. (“Tongmei”), entered into an operating lease for the land it owns with our consolidated joint venture Beijing BoYu Semiconductor Vessel Craftwork Technology Co., Ltd. The lease agreement for the land of approximately 22,081 square feet commenced on January 1, 2012 for a term of 10 years with annual lease payments of $24,000 subject to a 5% increase at each third year anniversary. The annual lease payment is due by January 31 of each year.
	Tongmei has paid $121,000 on behalf of Donghai County Dongfang High Purity Electronic Materials Co., Ltd.(“Dongfang”), its equity investment entity, to purchase materials. In 2014, an agreement was signed between Tongmei and Dongfang to set the date of repayment on December 31, 2015. As of March 31, 2015, this balance was included in “Related party notes receivable – short term” in our condensed consolidated balance sheets.
	In April 2014, Tongmei loaned an additional of $49,000 to Dongfang. The loan bears interest at 6.15% per annum and the principal and interest totaling $52,000 as of March 31, 2015 is due on December 31, 2015. As of March 31, 2015, this balance, including both principal and interest, was included in “Related party notes receivable – short term” in our condensed consolidated balance sheets.
	Tongmei also purchases raw materials from one of our equity investment entities for production in the ordinary course of business. As of March 31, 2015 and December 31 2014, amounts payable of $465,000 and $513,000, respectively, were included in “accounts payable” in our condensed consolidated balance sheets.
	Beijing Kaide Quartz Co. Ltd. (“Kaide”) has been a supplier of customized quartz tubes to the Company since 2004. Beijing XiangHeMing Trade Co. Ltd., (“XiangHeMing”) is a significant shareholder of Kaide. XiangHeMing was previously owned by, among others, certain immediate family members of Davis Zhang, our President, China Operations, until at least sometime in 2004, at which time the official Chinese government records indicate that Mr. Zhang’s immediate family members transferred their ownership of XiangHeMing to a third party. However, we are currently unable to conclusively determine whether Mr. Zhang’s immediate family members retained any economic interest in XiangHeMing after the transfer. As of March 31, 2015 and December 31 2014, amounts payable of $637,000 and $730,000, respectively, were included in “accounts payable” in our condensed consolidated balance sheets.
	Our Related Party Transactions Policy seeks to prohibit all conflicts of interest in transactions between related parties and us, unless they have been approved by our Board of Directors. This policy applies to all of our employees and directors, our subsidiaries and our joint ventures. Our executive officers retain board seats on the board of directors of the companies in which we have invested in our China joint ventures. See Note 6 for further details.

Investments_in_Privatelyheld_C

Investments in Privately-held Companies	3 Months Ended
	Mar. 31, 2015
Investments in Privately-held Companies [Abstract]
Investments in Privately-held Companies	Note 6. Investments in Privately-held Companies
	We have made strategic investments in private companies located in China in order to gain access at a competitive cost to raw materials that are critical to our substrate business. These companies form part of our overall supply chain.
	Our investments are summarized below (in thousands):
			InvestmentBalanceasof
	Company		March31,		December31,		Accounting	Ownership
			2015		2014		Method	Percentage
	Beijing JiYa Semiconductor Material Co., Ltd.		$	3,331	$	3,331	Consolidated		46	%
	Nanjing Jin Mei Gallium Co., Ltd.			592		592	Consolidated		83	%
	Beijing BoYu Semiconductor Vessel Craftwork Technology Co., Ltd.			1,346		1,346	Consolidated		70	%
			$	5,269	$	5,269
	Donghai County Dongfang High Purity Electronic Materials Co., Ltd.		$	1,682	$	1,723	Equity		46	%
	Xilingol Tongli Germanium Co. Ltd.			5,440		5,351	Equity		25	%
	Emeishan Jia Mei High Purity Metals Co., Ltd.			1,025		1,021	Equity		25	%
			$	8,147	$	8,095
	Our ownership of Beijing JiYa Semiconductor Material Co., Ltd. (JiYa) is 46%. We continue to consolidate JiYa as we have significant influence in management and have majority control of the board. Our Chief Executive Officer is chairman of the JiYa board and two other of our employees are also members of the board.
	Our ownership of Nanjing Jin Mei Gallium Co., Ltd. (Jin Mei) is 83%. We continue to consolidate Jin Mei as we have significant influence in management and have majority control of the board. Our Chief Executive Officer is chairman of the Jin Mei board and two other of our employees are also members of the board.
	Our ownership of Beijing BoYu Semiconductor Vessel Craftwork Technology Co., Ltd (BoYu) is 70%. We continue to consolidate BoYu as we have a significant influence in management and have majority control of the board. Our Chief Executive Officer is chairman of the BoYu board and two other of our employees are also members of the board.
	Although we have representation on the boards of directors of each of these companies, the daily operations of each of these companies are managed by local management and not by us. Decisions concerning their respective short-term strategy and operations, any capacity expansion and annual capital expenditures, and decisions concerning sales of finished product, are made by local management with some inputs from us.
	During the three months ended March 31, 2015 and 2014, the three consolidated joint ventures generated $0.6 million and $0.8 million of income, respectively, of which $125,000 and $205,000, respectively, were allocated to minority interests, resulting in $427,000 and $548,000 of income, respectively, to our net income (loss).
	For the three minority investment entities that are not consolidated, the investment balances are included in “other assets” in our consolidated balance sheets and totaled $8.1 million and $8.1 million as of March 31, 2015 and December 31, 2014, respectively. We own 46% of the ownership interests in one of these companies and 25% in each of the other two companies.  These three companies are not considered variable interest entities because:
		·	all three companies have sustainable businesses of their own;
		·	our voting power is proportionate to our ownership interests;
		·	we only recognize our respective share of the losses and/or residual returns generated by the companies if they occur; and
		·	we do not have controlling financial interest in, do not maintain operational or management control of, do not control the board of directors of, and are not required to provide additional investment or financial support to any of these companies.
	We also maintain minority investments indirectly in privately-held companies through our consolidated joint ventures. These minority investments are accounted for under the equity method in the books of our consolidated joint ventures. As of March 31, 2015 and December 31, 2014, our consolidated joint ventures included these minority investments in “other assets” in the consolidated balance sheets with a carrying value of $4.3 million and $4.0 million, respectively.
	The minority investment entities that are not consolidated are accounted for under the equity method and had the following summarized income information (in thousands) for the three months ended March 31, 2015 and 2014.
			ThreeMonthsEnded
			March31,
			2015		2014
	Revenue		$	9,325	$	13,480
	Gross profit			2,295		3,963
	Operating income			1,051		2,664
	Net income			957		2,119
	Our portion of the entity earnings from the minority investment entities that are not consolidated and are accounted for under the equity method were $200,000 and $487,000 for the three months ended March 31, 2015 and March 31, 2014, respectively.
	We also maintain minority investments directly in one privately-held company accounted for under the cost method and we do not have the ability to exercise significant influence over their operations. As of March 31, 2015 and December 31, 2014, our investments in this unconsolidated privately-held company had a carrying value of $200,000 and are included in “other assets” in the condensed consolidated balance sheets.

Stockholders_Equity_and_Stock_

Stockholders' Equity and Stock Repurchase Program	3 Months Ended
	Mar. 31, 2015
Stockholders' Equity and Stock Repurchase Program [Abstract]
Stockholders' Equity and Stock Repurchase Program	Note 7. Stockholders’ Equity and Stock Repurchase Program
	Consolidated Statements of Changes in Equity
		Preferred		Common		Additional			Accumulated			Other			AXT,Inc.			Noncontrolling			Total
		Stock		Stock		PaidInCapital			Deficit			Comprehensive			stockholders’			interests			stockholders’
												Income/(loss)			equity						equity
	Balance as of December 31, 2014	$	3,532	$	32	$	195,419		$	(68,393	)	$	7,673		$	138,263		$	6,425		$	144,688
	Common stock options exercised						76									76						76
	Common stock repurchased						(617	)								(617	)					(617	)
	Stock-based compensation						274									274						274
	Net (loss) income									(1,024	)					(1.024	)		125			(899	)
	Dividends declared by joint ventures																		(83	)		(83	)
	Change in unrealized (loss) gain on marketable securities												(259	)		(259	)					(259	)
	Currency translation adjustment												206			206			32			238
	Balance as of March 31, 2015	$	3,532	$	32	$	195,152		$	(69,417	)	$	7,620		$	136,919		$	6,499		$	143,418
	There were no reclassification adjustments from accumulated other comprehensive income for the three months ended March 31, 2015 and March 31, 2014.
	Stock Repurchase Programs
	On February 21, 2013, our Board of Directors approved a stock repurchase program pursuant to which we may repurchase up to $6.0 million of our outstanding common stock through February 27, 2014. These purchases can be made from time to time in the open market and are funded from our existing cash balances and cash generated from operations. During 2013, we repurchased approximately 285,000 shares at an average price of $2.51 per share for a total purchase price of $716,000 under the stock repurchase program. As of December 31, 2013, approximately $5.3 million remained available for future repurchases under this program. No shares were repurchased in 2014 under this program and the plan expired on February 27, 2014. On October 27, 2014, our Board of Directors approved a stock repurchase program pursuant to which we may repurchase up to $5.0 million of our outstanding common stock.  These repurchases can be made from time to time in the open market and are funded from our existing cash balances and cash generated from operations. During the three months ended March 31, 2015, we repurchased approximately 230,000 shares at an average price of $2.67 per share for a total purchase price of $617,000 under the stock repurchase program. As of March 31, 2015, approximately $4.4 million remained available for future repurchases under this program. See Item 2, Unregistered Sales of Equity Securities and Use of Proceeds in Part II, Other Information, for additional information.

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2015
Stock-Based Compensation [Abstract]
Stock-Based Compensation	Note 8. Stock-Based Compensation
	We account for stock-based compensation in accordance with the provisions of FASB Accounting Standards Codification (“ASC”) topic 718, Compensation-Stock Compensation (“ASC 718”), which established accounting for stock-based awards exchanged for employee services. Stock-based compensation cost is measured at each grant date, based on the fair value of the award, and is recognized as expense over the employee’s requisite service period of the award. All of our stock compensation is accounted for as an equity instrument.
	The following table summarizes compensation costs related to our stock-based awards (in thousands, except per share data):
		ThreeMonthsEnded
		March31,
		2015			2014
	Cost of revenue	$	5		$	5
	Selling, general and administrative		225			244
	Research and development		44			43
	Total stock-based compensation		274			292
	Tax effect on stock-based compensation		—			—
	Net effect on net income (loss)	$	274		$	292
	As of March 31, 2015, the unamortized compensation costs related to unvested stock options granted to employees under our stock option plans were approximately $1.4 million, net of estimated forfeitures of $54,000. These costs are amortized on a straight-line basis over a weighted-average period of approximately 2.7 years and will be adjusted for subsequent changes in estimated forfeitures. We elected not to capitalize any stock-based compensation to inventory as of March 31, 2015 due to the immateriality of the amount.
	We estimate the fair value of stock options using a Black-Scholes valuation model, consistent with the provisions of ASC 718. There were no stock options granted in the three months ended March 31, 2015 and 2014.
	The following table summarizes our stock option activities during the three months ended March 31, 2015 (in thousands, except per share data):
	Stock Options	Shares			Weighted-		Weighted-		Aggregate
					average		average		Intrinsic
					Exercise		Remaining		Value
					Price		Contractual
							Life
							(inyears)
	Balance as of January 1, 2015		3,198		$	3.12		6.95	$	1,247
	Granted		—			—
	Exercised		(54	)		1.4
	Canceled and expired		(29	)		2.74
	Balance as of March 31, 2015		3,115		$	3.16		6.72	$	966
	Options vested and expected to vest as of March 31, 2015		3,115		$	3.16		6.72	$	966
	Options exercisable as of March 31, 2015		1,885		$	3.51		5.35	$	667
	The aggregate intrinsic value in the table above represents the total pretax intrinsic value, based on our closing price of $2.69 on March 31, 2015, which would have been received by the option holder had all option holders exercised their options on that date.
	Restricted stock awards
	A summary of activity related to restricted stock awards for the three months ended March 31, 2015 is presented below (in thousands, except per share data):
	Stock Awards	Shares			Weighted-Average
					GrantDateFairValue
	Non-vested as of January 1, 2015		261		$	2.71
	Granted		—		$	—
	Vested		—		$	—
	Non-vested as of March 31, 2015		261		$	2.71
	As of March 31, 2015, the unamortized compensation costs related to unvested restricted stock awards was approximately $511,000, which is to be amortized on a straight-line basis over a weighted-average period of approximately 2.2 years.

Net_Income_loss_Per_Share

Net Income (loss) Per Share	3 Months Ended
	Mar. 31, 2015
Net Income (loss) Per Share [Abstract]
Net Income (loss) Per Share	Note 9. Net Income (loss) Per Share
	Basic net income (loss) per share is computed using the weighted-average number of common shares outstanding during the periods less shares of common stock subject to repurchase and non-vested stock awards. Diluted net income (loss) per share is computed using the weighted-average number of common shares outstanding and potentially dilutive common shares outstanding during the periods. The dilutive effect of outstanding stock options and restricted stock awards is reflected in diluted earnings per share by application of the treasury stock method. Potentially dilutive common shares consist of common shares issuable upon the exercise of stock options. Potentially dilutive common shares are excluded in net loss periods, as their effect would be anti-dilutive.
	A reconciliation of the numerators and denominators of the basic and diluted net loss per share calculations is as follows (in thousands, except per share data):
		ThreeMonthsEnded
		March31,
		2015			2014
	Numerator:
	Net loss attributable to AXT, Inc.	$	(1,024	)	$	(2,040	)
	Less: Preferred stock dividends		(44	)		(44	)
	Net loss available to common stockholders	$	(1,068	)	$	(2,084	)
	Denominator:
	Denominator for basic net loss per share - weighted average common shares		32,553			32,364
	Effect of dilutive securities:
	Common stock options		—			—
	Restricted stock awards		—			—
	Denominator for dilutive net loss per common share		32,553			32,364
	Net loss attributable to AXT, Inc. per common share:
	Basic	$	(0.03	)	$	(0.06	)
	Diluted	$	(0.03	)	$	(0.06	)
	Weighted-average shares:
	Options excluded from diluted net loss per share as the impact is anti-dilutive		3,167			2,607
	Restricted stock excluded from diluted net loss  per share as the impact is anti-dilutive		261			241
	The 883,000 shares of $0.001 par value Series A preferred stock issued and outstanding as of March 31, 2015 and December 31, 2014, valued at $3,532,000, are non-voting and non-convertible preferred stock with a 5.0% cumulative annual dividend rate payable when declared by the board of directors and a $4 per share liquidation preference over common stock, which must be paid before any distribution is made to common stockholders. These preferred shares were issued to Lyte Optronics, Inc. stockholders in connection with the completion of our acquisition of Lyte Optronics, Inc. on May 28, 1999.

Segment_Information_and_Foreig

Segment Information and Foreign Operations	3 Months Ended
	Mar. 31, 2015
Segment Information and Foreign Operations [Abstract]
Segment Information and Foreign Operations	Note 10. Segment Information and Foreign Operations
	Segment Information
	We operate in one segment for the design, development, manufacture and distribution of high-performance compound semiconductor substrates and sale of materials. In accordance with ASC topic 280, Segment Reporting, our chief operating decision-maker has been identified as our Chief Executive Officer, who reviews operating results to make decisions about allocating resources and assessing performance for the Company. Since we operate in one segment, all financial segment and product line information can be found in our condensed consolidated financial statements.
	The following table represents revenue amounts (in thousands) reported for products shipped to customers in the corresponding geographic region:
		ThreeMonthsEnded
		March31,
		2015		2014
	Geographical information:
	Europe (primarily Germany)	$	4,943	$	6,583
	China		3,297		4,165
	Asia Pacific (excluding China, Japan and Taiwan)		2,759		2,389
	Taiwan		3,109		2,115
	Japan		2,484		2,313
	North America (primarily the United States)		3,472		1,780
	Total	$	20,064	$	19,345
	Long-lived assets consist primarily of property, plant and equipment, and are attributed to the geographic location in which they are located. Long-lived assets by geographic region were as follows (in thousands):
		Asof
		March31,		December31,
		2015		2014
	Long-lived assets by geographic region:
	United States of America	$	403	$	136
	China		32,820		33,726
		$	33,223	$	33,862
	Significant Customers
	No customer represented more than 10% of our revenue for the three months ended March 31, 2015 and 2014. Our top five customers, although not the same five customers for each period, represented 35% and 39% of our revenue for the three months ended March 31, 2015 and 2014, respectively.
	We perform ongoing credit evaluations of our customers’ financial condition, and limit the amount of credit extended when deemed necessary, but generally do not require collateral. No customer accounted for over 10% of our accounts receivable balance as of March 31, 2015 while two customers accounted for 11% and 10% of our accounts receivable balance as of December 31, 2014.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies [Abstract]
Commitments and Contingencies	Note 11. Commitments and Contingencies
	Indemnification Agreements
	We have entered into indemnification agreements with our directors and officers that require us to indemnify our directors and officers against liabilities that may arise by reason of their status or service as directors or officers, other than liabilities arising from willful misconduct of a culpable nature; to advance their expenses incurred as a result of any proceeding against them as to which they could be indemnified; and to obtain directors’ and officers’ insurance if available on reasonable terms, which we currently have in place.
	Product Warranty
	We provide warranties for our products for a specific period of time, generally twelve months, against material defects. We provide for the estimated future costs of warranty obligations in cost of sales when the related revenue is recognized. The accrued warranty costs represent the best estimate at the time of sale of the total costs that we expect to incur to repair or replace product parts that fail while still under warranty. The amount of accrued estimated warranty costs are primarily based on historical experience as to product failures as well as current information on repair costs. On a quarterly basis, we review the accrued balances and update the historical warranty cost trends. The following table reflects the change in our warranty accrual which is included in “accrued liabilities” on the condensed consolidated balance sheets, during the three months ended March 31, 2015 and 2014 (in thousands):
		ThreeMonthsEnded
		March31,
		2015			2014
	Beginning accrued warranty and related costs	$	802		$	1,048
	Accruals for warranties issued		174			496
	Adjustments related to pre-existing warranties including expirations and changes in estimates		(294	)		(103	)
	Cost of warranty repair		(290	)		(214	)
	Ending accrued warranty and related costs	$	392		$	1,227
	Contractual Obligations
	We lease certain office space, warehouse facilities and equipment under long-term operating leases expiring at various dates through December 2025. The majority of our lease obligations relates to our lease agreement for the facility in Fremont, California with approximately 19,467 square feet.
	We entered into a royalty agreement with a competitor effective December 3, 2010 with a term of eight years, terminating December 31, 2018.  We and our related companies are granted a worldwide, nonexclusive, royalty bearing, irrevocable license to certain patents for the term on the agreement. We shall pay a total of $7.0 million royalty payment over eight years that began in 2011 based on future royalty bearing sales. This agreement contains a clause that allows us to claim for credit, starting in 2013, in the event that the royalty bearing sales for the year is lower than a pre-determined amount set forth in this agreement.
	Outstanding contractual obligations as of March 31, 2015 are summarized as follows (in thousands):
		Paymentsduebyperiod
	Contractual Obligations	Total			Lessthan1year			3-Jan		5-Apr		Morethan
								years		years		5years
	Operating leases	$	690		$	236		$	289	$	54	$	111
	Royalty agreement		2,325			744			1,150		431		—
	Total	$	3,015		$	980		$	1,439	$	485	$	111
	Purchase Obligations with Penalties for Cancellation
	In the normal course of business, we issue purchase orders to various suppliers. In certain cases, we may incur a penalty if we cancel the purchase order. As of March 31, 2015, we do not have any outstanding purchase orders that will incur a penalty if cancelled by the Company.
	Legal Proceedings
	From time to time we may be involved in judicial or administrative proceedings concerning matters arising in the ordinary course of business. We do not expect that any of these matters, individually or in the aggregate, will have a material adverse effect on our business, financial condition, cash flows or results of operation.

Foreign_Exchange_Transaction_G

Foreign Exchange Transaction Gains/Losses	3 Months Ended
	Mar. 31, 2015
Foreign Exchange Transaction Gains/Losses [Abstract]
Foreign Exchange Transaction Gains/Losses	Note 12. Foreign Exchange Transaction Gains/Losses
	We incurred foreign currency transaction exchange gains of $180,000 and $17,000 for the three months ended March 31, 2015 and 2014, respectively. These amounts are included in “Other income, net” on our condensed consolidated statements of operations.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Taxes [Abstract]
Income Taxes	Note 13. Income Taxes
	We account for income taxes in accordance with ASC topic 740, Income Taxes (“ASC 740”) which requires that deferred tax assets and liabilities be recognized using enacted tax rates for the effect of temporary differences between the book and tax bases of recorded assets and liabilities. ASC 740 also requires that deferred tax assets be reduced by a valuation allowance if it is more likely than not that a portion of the deferred tax asset will not be realized.
	In accordance with Section 382 of the Internal Revenue Code, the amounts of and benefits from net operating loss and tax credit carryforwards may be impaired or limited in certain circumstances. Events which cause limitations in the amount of net operating losses or credits that we may utilize in any one year include, but are not limited to, a cumulative ownership change of more that 50% as defined, over a three year period. As a result of the implementation of Interpretation 48, we recognized $16.4 million of liability for unrecognized tax benefits. Of this amount, none was accounted for as a reduction to balance of retained earnings. The amount decreased tax loss carryforwards in the U.S., which are fully offset by a valuation allowance.
	We recognize interest and penalties related to uncertain tax positions in income tax expense. Income tax expense for the three month ended March 31, 2015 includes no interest and penalties. As of March 31, 2015, we have no accrued interest and penalties related to uncertain tax positions. We file income tax returns in the U.S. federal, various states and foreign jurisdictions. We have substantially concluded all U.S. federal and state income tax matters through December 31, 2013.
	Provision for income taxes for three months ended March 31, 2015 and 2014 was mostly related to our China subsidiaries and our China joint venture operations. We have made a tax election in China whereby certain minimum foreign withholding taxes are treated as an expense and not a tax credit. Besides the state taxes liabilities, no federal income tax benefit or expense has been provided for the three months ended March 31, 2015 or 2014 due to our net loss, our valuation allowance being utilized and uncertainty of future profits in the U.S.

Restructuring_Charges

Restructuring Charges	3 Months Ended
	Mar. 31, 2015
Restructuring Charges [Abstract]
Restructuring Charges	Note 14. Restructuring Charges
	On February 25, 2014, we announced a restructuring plan with respect to our wholly-owned subsidiary, Beijing Tongmei Xtal Technology Co, Ltd. (“Tongmei”) in order to better align manufacturing capacity with demand. Under the restructuring plan, Tongmei implemented certain workforce reductions with respect to its manufacturing facility in China. We also announced that the restructuring plan would be completed by March 31, 2014, depending on local legal requirements.
	In the first quarter of 2014, we reduced the workforce at Tongmei by approximately 93 positions that were no longer required to support production and operations, or approximately 11 percent of the workforce. Accordingly, we recorded a restructuring charge of approximately $907,000 related to the reduction in force for severance-related expenses. As of March 31, 2014, we completed this restructuring plan and the reduction in force. We had no restructuring charge in the first three months of 2015.

Whistleblower_Complaint_and_In

Whistleblower Complaint and Investigation	3 Months Ended
	Mar. 31, 2015
Whistleblower Complaint and Investigation [Abstract]
Whistleblower Complaint and Investigation	Note 15. Whistleblower Complaint and Investigation
	On February 23, 2015, the Board of Directors announced that, pursuant to an anonymous whistleblower complaint, our Audit Committee has conducted an investigation of certain potential related-party transactions involving Davis Zhang, our President, China Operations. The investigation did not conclude that there was any intentional misconduct by Mr. Zhang, or that he received any improper benefit from these transactions. Further, the investigation did not reveal any inaccuracies in our financial statements resulting from these transactions. However, the investigation identified certain historical related-party transactions that were not previously disclosed in our filings with the Securities and Exchange Commission (“SEC”). We have filed a Current Report on Form 8-K with the SEC on February 23, 2015 to disclose such historical related-party transactions.
	On February 20, 2015, the Board waived any potential inconsistencies with our Code of Conduct and Ethics arising from the transactions identified in the investigation. Also, the Audit Committee approved the related-party nature of such transactions to the extent it had not previously approved such transactions. The Board and Audit Committee specified that such waiver and approval would have retroactive effect to the date of commencement of the transactions covered by such waiver and approval. We have incurred approximately $1.8 million of professional service fees during the course of this investigation.

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2015
Recent Accounting Pronouncements [Abstract]
Recent Accounting Pronouncements	Note 16. Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board issued a new standard to achieve a consistent application of revenue recognition within the U.S., resulting in a single revenue model to be applied by reporting companies under U.S. generally accepted accounting principles. Under the new model, recognition of revenue occurs when a customer obtains control of promised goods or services in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In addition, the new standard requires that reporting companies disclose the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The new standard is effective for us beginning in the first quarter of 2018; early adoption is prohibited. The new standard is required to be applied retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying it recognized at the date of initial application.

Subsequent_Events

Subsequent Events	3 Months Ended
	Mar. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	Note 17. Subsequent Events
	Resignation of Davis Zhang
	On April 17, 2015, Davis Zhang notified us of his decision to resign as our President, China Operations.  His resignation will be effective as of May 15, 2015.
	Gallium arsenide materials were placed on a revised list of hazardous substances requiring a permit for use in manufacturing.  We do not yet have that permit.
	From time to time, the Chinese government issues new regulations, which may require additional actions on our part to comply.  On February 27, 2015, the China State Administration of Work Safety updated its list of hazardous substances.  The previous list, which was published in 2002, did not restrict the materials that we use in our wafers.  The new list added gallium arsenide.  As a result of the newly published list, we were required to obtain a permit by May 1, 2015 to continue to manufacture our gallium arsenide substrate wafers.  We initiated discussions with the local district agency to obtain the requisite permit.  On May 4, 2015, we were instructed by the local district agency that because we had not yet received the requisite permit, we should cease manufacturing our gallium arsenide substrate wafers or we should obtain permission to continue manufacturing our gallium arsenide substrate wafers from a municipal-level office, such as the Beijing municipal authority.  The Beijing municipal authority accepted our application on May 7, 2015 and our application is under review.  We expect to continue to manufacture gallium arsenide substrate wafers while going through the compliance examination process to receive the requisite permit.  If we do not receive the requisite permit to continue to manufacture gallium arsenide substrate wafers, we may be required to cease manufacturing such wafers until we receive the requisite permit.  A halt to our production of gallium arsenide substrate wafers could have a material adverse effect on our revenue and profits and could also result in our furloughing approximately several hundred manufacturing employees.  See the section entitled “Risk Factors” for additional information about these risks and uncertainties.

Investments_and_Fair_Value_Mea1

Investments and Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Investments and Fair Value Measurements [Abstract]
Cash, cash equivalents and investments	Our cash and cash equivalents consist of cash and instruments with original maturities of less than 90 days. Our investments consist of instruments with original maturities of more than 90 days. As of March 31, 2015 and December 31, 2014, our cash, cash equivalents and investments are classified as follows (in thousands):
			March31,2015											December31,2014
			Amortized		Gross			Gross			Fair			Amortized		Gross			Gross			Fair
			Cost		Unrealized			Unrealized			Value			Cost		Unrealized			Unrealized			Value
					Gain			(Loss)								Gain			(Loss)
	Classified as:
	Cash		$	25,662	$	—		$	—		$	25,662		$	22,337	$	—		$	—		$	22,337
	Cash equivalents:
	Certificates of deposit1			7,623		—			—			7,623			6,454		—			—			6,454
	Money market fund			—		—			—			—			23		—			—			23
	Total cash and cash equivalents			33,285		—			—			33,285			28,814		—			—			28,814
	Investments (available for sale):
	Certificates of deposit2			6,425		1			(7	)		6,419			10,195		1			(13	)		10,183
	Corporate bonds			7,342		—			(31	)		7,311			9,214		1			(29	)		9,186
	Corporate equity security			24		448			—			472			44		710			—			754
	Total investments			13,791		449			(38	)		14,202			19,453		712			(42	)		20,123
	Total cash, cash equivalents and investments		$	47,076	$	449		$	(38	)	$	47,487		$	48,267	$	712		$	(42	)	$	48,937
	Contractual maturities on investments:
	Due within 1 year		$	3,144							$	3,590		$	11,631							$	12,340
	Due after 1 through 5 years			10,647								10,612			7,822								7,783
			$	13,791							$	14,202		$	19,453							$	20,123
	1	Certificate of deposit with original maturities of less than 90 days.
	2	Certificate of deposit with original maturities of more than 90 days.
Fair value and gross unrealized losses related to available-for-sale securities	The following table summarizes the fair value and gross unrealized losses related to available-for-sale securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of March 31, 2015 (in thousands):
	As of March 31, 2015		InLossPosition					InLossPosition						TotalIn
			<12months					>12months						LossPosition
			Fair		Gross			Fair			Gross			Fair		Gross
			Value		Unrealized			Value			Unrealized			Value		Unrealized
					(Loss)						(Loss)					(Loss)
	Investments:
	Certificates of deposit		$	4,018	$	(7	)	$	480		$	—		$	4,498	$	(7	)
	Corporate bonds			7,311		(31	)		—			—			7,311		(31	)
	Total in loss position		$	11,329	$	(38	)	$	480		$	—		$	11,809	$	(38	)
	A portion of our investments would generate a loss if we sold them on March 31, 2015. The following table summarizes the fair value and gross unrealized losses related to available-for-sale securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of December 31, 2014 (in thousands):
	As of December 31, 2014		InLossPosition					InLossPosition						TotalIn
			<12months					>12months						LossPosition
			Fair		Gross			Fair			Gross			Fair		Gross
			Value		Unrealized			Value			Unrealized			Value		Unrealized
					(Loss)						(Loss)					(Loss)
	Investments:
	Certificates of deposit		$	4,492	$	(13	)	$	—		$	—		$	4,492	$	(13	)
	Corporate bonds			3,770		(27	)		4,309			(2	)		8,079		(29	)
	Total in loss position		$	8,262	$	(40	)	$	4,309		$	(2	)	$	12,571	$	(42	)
Summary of financial assets and liabilities measured at fair value on a recurring basis	The following table summarizes our financial assets and liabilities measured at fair value on a recurring basis in accordance with ASC 820 as of March 31, 2015 (in thousands):
			Balance as of		Quoted Prices in			Significant Other			Significant
			31-Mar-15		Active Markets of			Observable Inputs			Unobservable Inputs
					Identical Assets			(Level2)			(Level 3)
					(Level1)
	Assets:
	Cash equivalents and investments:
	Certificates of deposit		$	14,042	$	—		$	14,042		$	—
	Corporate bonds			7,311		—			7,311			—
	Corporate equity securities			472		472			—			—
	Total		$	21,825	$	472		$	21,353		$	—
	Liabilities:
	Foreign currency hedge obligations		$	2	$	—		$	—		$	2
	The following table summarizes our financial assets and liabilities measured at fair value on a recurring basis in accordance with ASC 820 as of December 31, 2014 (in thousands):
			Balance as of		Quoted Prices in			Significant Other			Significant
			31-Dec-14		Active Markets of			Observable Inputs			Unobservable Inputs
					Identical Assets			(Level2)			(Level 3)
					(Level1)
	Assets:
	Cash equivalents and investments:
	Money market fund		$	23	$	23		$	—		$	—
	Certificates of deposit			10,183		—			10,183			—
	Corporate bonds			9,186		—			9,186			—
	Corporate equity securities			754		754			—			—
	Total		$	20,146	$	777		$	19,369		$	—
	Liabilities		$	—	$	—		$	—		$	—

Inventories_Tables

Inventories (Tables)	3 Months Ended
	Mar. 31, 2015
Inventories [Abstract]
Components of inventories	The components of inventories are summarized below (in thousands):
		March31,		December31,
		2015		2014
	Inventories:
	Raw materials	$	19,688	$	18,990
	Work in process		16,948		16,222
	Finished goods		2,839		3,362
		$	39,475	$	38,574

Accrued_Liabilities_Tables

Accrued Liabilities (Tables)	3 Months Ended
	Mar. 31, 2015
Accrued Liabilities [Abstract]
Components of accrued liabilities	The components of accrued liabilities are summarized below (in thousands):
		March31,		December31,
		2015		2014
	Accrued product warranty	$	392	$	802
	Accrued compensation and related charges		1,718		2,656
	Current portion of royalty payments		744		800
	Dividends payable by consolidated joint ventures		646		563
	Accrued professional services		304		509
	Accrued income taxes		110		119
	Other accrued liabilities		1,901		2,185
		$	5,815	$	7,634

Investments_in_Privatelyheld_C1

Investments in Privately-held Companies (Tables)	3 Months Ended
	Mar. 31, 2015
Investments in Privately-held Companies [Abstract]
Investments	Our investments are summarized below (in thousands):
		InvestmentBalanceasof
	Company	March31,		December31,		Accounting	Ownership
		2015		2014		Method	Percentage
	Beijing JiYa Semiconductor Material Co., Ltd.	$	3,331	$	3,331	Consolidated		46	%
	Nanjing Jin Mei Gallium Co., Ltd.		592		592	Consolidated		83	%
	Beijing BoYu Semiconductor Vessel Craftwork Technology Co., Ltd.		1,346		1,346	Consolidated		70	%
		$	5,269	$	5,269
	Donghai County Dongfang High Purity Electronic Materials Co., Ltd.	$	1,682	$	1,723	Equity		46	%
	Xilingol Tongli Germanium Co. Ltd.		5,440		5,351	Equity		25	%
	Emeishan Jia Mei High Purity Metals Co., Ltd.		1,025		1,021	Equity		25	%
		$	8,147	$	8,095
Summarized income information	The minority investment entities that are not consolidated are accounted for under the equity method and had the following summarized income information (in thousands) for the three months ended March 31, 2015 and 2014.
		ThreeMonthsEnded
		March31,
		2015		2014
	Revenue	$	9,325	$	13,480
	Gross profit		2,295		3,963
	Operating income		1,051		2,664
	Net income		957		2,119

Stockholders_Equity_and_Stock_1

Stockholders' Equity and Stock Repurchase Program (Tables)	3 Months Ended
	Mar. 31, 2015
Stockholders' Equity and Stock Repurchase Program [Abstract]
Consolidated statement of changes in equity	Consolidated Statements of Changes in Equity
		Preferred		Common		Additional			Accumulated			Other			AXT,Inc.			Noncontrolling			Total
		Stock		Stock		PaidInCapital			Deficit			Comprehensive			stockholders’			interests			stockholders’
												Income/(loss)			equity						equity
	Balance as of December 31, 2014	$	3,532	$	32	$	195,419		$	(68,393	)	$	7,673		$	138,263		$	6,425		$	144,688
	Common stock options exercised						76									76						76
	Common stock repurchased						(617	)								(617	)					(617	)
	Stock-based compensation						274									274						274
	Net (loss) income									(1,024	)					(1.024	)		125			(899	)
	Dividends declared by joint ventures																		(83	)		(83	)
	Change in unrealized (loss) gain on marketable securities												(259	)		(259	)					(259	)
	Currency translation adjustment												206			206			32			238
	Balance as of March 31, 2015	$	3,532	$	32	$	195,152		$	(69,417	)	$	7,620		$	136,919		$	6,499		$	143,418

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Stock-Based Compensation [Abstract]
Compensation costs related to stock-based awards	The following table summarizes compensation costs related to our stock-based awards (in thousands, except per share data):
		ThreeMonthsEnded
		March31,
		2015			2014
	Cost of revenue	$	5		$	5
	Selling, general and administrative		225			244
	Research and development		44			43
	Total stock-based compensation		274			292
	Tax effect on stock-based compensation		—			—
	Net effect on net income (loss)	$	274		$	292
Summary of stock option activity	The following table summarizes our stock option activities during the three months ended March 31, 2015 (in thousands, except per share data):
	Stock Options	Shares			Weighted-		Weighted-		Aggregate
					average		average		Intrinsic
					Exercise		Remaining		Value
					Price		Contractual
							Life
							(inyears)
	Balance as of January 1, 2015		3,198		$	3.12		6.95	$	1,247
	Granted		—			—
	Exercised		(54	)		1.4
	Canceled and expired		(29	)		2.74
	Balance as of March 31, 2015		3,115		$	3.16		6.72	$	966
	Options vested and expected to vest as of March 31, 2015		3,115		$	3.16		6.72	$	966
	Options exercisable as of March 31, 2015		1,885		$	3.51		5.35	$	667
Restricted stock awards	A summary of activity related to restricted stock awards for the three months ended March 31, 2015 is presented below (in thousands, except per share data):
	Stock Awards	Shares			Weighted-Average
					GrantDateFairValue
	Non-vested as of January 1, 2015		261		$	2.71
	Granted		—		$	—
	Vested		—		$	—
	Non-vested as of March 31, 2015		261		$	2.71

Net_Income_loss_Per_Share_Tabl

Net Income (loss) Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Net Income (loss) Per Share [Abstract]
Reconciliation of numerators and denominators of basic and diluted net income (loss) per share	A reconciliation of the numerators and denominators of the basic and diluted net loss per share calculations is as follows (in thousands, except per share data):
		ThreeMonthsEnded
		March31,
		2015			2014
	Numerator:
	Net loss attributable to AXT, Inc.	$	(1,024	)	$	(2,040	)
	Less: Preferred stock dividends		(44	)		(44	)
	Net loss available to common stockholders	$	(1,068	)	$	(2,084	)
	Denominator:
	Denominator for basic net loss per share - weighted average common shares		32,553			32,364
	Effect of dilutive securities:
	Common stock options		—			—
	Restricted stock awards		—			—
	Denominator for dilutive net loss per common share		32,553			32,364
	Net loss attributable to AXT, Inc. per common share:
	Basic	$	(0.03	)	$	(0.06	)
	Diluted	$	(0.03	)	$	(0.06	)
	Weighted-average shares:
	Options excluded from diluted net loss per share as the impact is anti-dilutive		3,167			2,607
	Restricted stock excluded from diluted net loss  per share as the impact is anti-dilutive		261			241

Segment_Information_and_Foreig1

Segment Information and Foreign Operations (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Information and Foreign Operations [Abstract]
Revenue reported for products shipped to customers in the corresponding geographic region	The following table represents revenue amounts (in thousands) reported for products shipped to customers in the corresponding geographic region:
		ThreeMonthsEnded
		March31,
		2015		2014
	Geographical information:
	Europe (primarily Germany)	$	4,943	$	6,583
	China		3,297		4,165
	Asia Pacific (excluding China, Japan and Taiwan)		2,759		2,389
	Taiwan		3,109		2,115
	Japan		2,484		2,313
	North America (primarily the United States)		3,472		1,780
	Total	$	20,064	$	19,345
Long-lived assets by geographic region	Long-lived assets consist primarily of property, plant and equipment, and are attributed to the geographic location in which they are located. Long-lived assets by geographic region were as follows (in thousands):
		Asof
		March31,		December31,
		2015		2014
	Long-lived assets by geographic region:
	United States of America	$	403	$	136
	China		32,820		33,726
		$	33,223	$	33,862

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies [Abstract]
Product warranty accrued liability	The following table reflects the change in our warranty accrual which is included in “accrued liabilities” on the condensed consolidated balance sheets, during the three months ended March 31, 2015 and 2014 (in thousands):
		ThreeMonthsEnded
		March31,
		2015			2014
	Beginning accrued warranty and related costs	$	802		$	1,048
	Accruals for warranties issued		174			496
	Adjustments related to pre-existing warranties including expirations and changes in estimates		(294	)		(103	)
	Cost of warranty repair		(290	)		(214	)
	Ending accrued warranty and related costs	$	392		$	1,227
Outstanding contractual obligations	Outstanding contractual obligations as of March 31, 2015 are summarized as follows (in thousands):
		Paymentsduebyperiod
	Contractual Obligations	Total			Lessthan1year			3-Jan		5-Apr		Morethan
								years		years		5years
	Operating leases	$	690		$	236		$	289	$	54	$	111
	Royalty agreement		2,325			744			1,150		431		—
	Total	$	3,015		$	980		$	1,439	$	485	$	111

Basis_of_Presentation_Details

Basis of Presentation (Details) (Majority-Owned Subsidiaries [Member])	Mar. 31, 2015
Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of ownership, equity method (in hundredths)	20.00%
Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of ownership, equity method (in hundredths)	50.00%

Investments_and_Fair_Value_Mea2

Investments and Fair Value Measurements (Details) (USD $)	3 Months Ended			12 Months Ended
	Mar. 31, 2015		Mar. 31, 2014	Dec. 31, 2014		Dec. 31, 2013
Cash, cash equivalents and investments [Abstract]
Cash	$25,662,000			$22,337,000
Cash equivalents [Abstract]
Certificates of deposit, amortized cost	7,623,000	[1]		6,454,000	[1]
Certificates of deposit, gross unrealized gain	0	[1]		0	[1]
Certificates of deposit, gross unrealized loss	0	[1]		0	[1]
Certificates of deposit, fair value	7,623,000	[1]		6,454,000	[1]
Money market fund	0			23,000
Total cash and cash equivalents	33,285,000		22,760,000	28,814,000		24,961,000
Amortized Cost	47,076,000			48,267,000
Gross Unrealized Gain	449,000			712,000
Gross Unrealized (Loss)	-38,000			-42,000
Fair Value	47,487,000			48,937,000
Contractual maturities on investments, amortized cost basis [Abstract]
Due within 1 year	3,144,000			11,631,000
Due after 1 through 5 years	10,647,000			7,822,000
Investments, amortized cost	13,791,000			19,453,000
Contractual maturities on investments, fair value basis [Abstract]
Due within 1 year	3,590,000			12,340,000
Due after 1 through 5 years	10,612,000			7,783,000
Investments, fair value	14,202,000			20,123,000
Proceeds from sales of available-for-sale investments	387,000		0
Gross realized gains from sales of available-for-sale investments	367,000		0
Unrealized gain, net of tax	448,000
Summary of fair value and gross unrealized losses related to available-for-sale securities [Abstract]
Fair value, in loss position less than twelve months	11,329,000			8,262,000
Gross unrealized loss, in loss position less than twelve months	-38,000			-40,000
Fair value, in loss position greater than twelve months	480,000			4,309,000
Gross unrealized loss, in loss position greater than twelve months	0			-2,000
Fair value, total in loss position	11,809,000			12,571,000
Gross unrealized loss, total in loss position	-38,000			-42,000
Minority Investments [Abstract]
Minority investments in unconsolidated privately-held companies	200,000			200,000
Other Assets [Member]
Minority Investments [Abstract]
Investments in privately-held companies	12,500,000			12,100,000
Minority investments in unconsolidated privately-held companies	200,000			200,000
Certificates of Deposit [Member]
Cash equivalents [Abstract]
Amortized Cost	6,425,000	[2]		10,195,000	[2]
Gross Unrealized Gain	1,000	[2]		1,000	[2]
Gross Unrealized (Loss)	-7,000	[2]		-13,000	[2]
Fair Value	6,419,000	[2]		10,183,000	[2]
Summary of fair value and gross unrealized losses related to available-for-sale securities [Abstract]
Fair value, in loss position less than twelve months	4,018,000			4,492,000
Gross unrealized loss, in loss position less than twelve months	-7,000			-13,000
Fair value, in loss position greater than twelve months	480,000			0
Gross unrealized loss, in loss position greater than twelve months	0			0
Fair value, total in loss position	4,498,000			4,492,000
Gross unrealized loss, total in loss position	-7,000			-13,000
Corporate Bonds [Member]
Cash equivalents [Abstract]
Amortized Cost	7,342,000			9,214,000
Gross Unrealized Gain	0			1,000
Gross Unrealized (Loss)	-31,000			-29,000
Fair Value	7,311,000			9,186,000
Summary of fair value and gross unrealized losses related to available-for-sale securities [Abstract]
Fair value, in loss position less than twelve months	7,311,000			3,770,000
Gross unrealized loss, in loss position less than twelve months	-31,000			-27,000
Fair value, in loss position greater than twelve months	0			4,309,000
Gross unrealized loss, in loss position greater than twelve months	0			-2,000
Fair value, total in loss position	7,311,000			8,079,000
Gross unrealized loss, total in loss position	-31,000			-29,000
Corporate Equity Security [Member]
Cash equivalents [Abstract]
Amortized Cost	24,000			44,000
Gross Unrealized Gain	448,000			710,000
Gross Unrealized (Loss)	0			0
Fair Value	472,000			754,000
Total Investments [Member]
Cash equivalents [Abstract]
Amortized Cost	13,791,000			19,453,000
Gross Unrealized Gain	449,000			712,000
Gross Unrealized (Loss)	-38,000			-42,000
Fair Value	$14,202,000			$20,123,000
[1]	Certificate of deposit with original maturities of less than 90 days.
[2]	Certificate of deposit with original maturities of more than 90 days.

Investments_and_Fair_Value_Mea3

Investments and Fair Value Measurements, Fair Value (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified
Cash Equivalents and Investments [Abstract]
Money market fund	$0		$23
Certificates of deposit	7,623	[1]	6,454	[1]
Recurring [Member]
Cash Equivalents and Investments [Abstract]
Money market fund			23
Certificates of deposit	14,042		10,183
Corporate bonds	7,311		9,186
Corporate equity securities	472		754
Total	21,825		20,146
Liabilities [Abstract]
Liabilities			0
Foreign currency hedge obligations	2
Recurring [Member] | Quoted Prices in Active Markets of Identical Assets (Level 1) [Member]
Cash Equivalents and Investments [Abstract]
Money market fund			23
Certificates of deposit	0		0
Corporate bonds	0		0
Corporate equity securities	472		754
Total	472		777
Liabilities [Abstract]
Liabilities			0
Foreign currency hedge obligations	0
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Cash Equivalents and Investments [Abstract]
Money market fund			0
Certificates of deposit	14,042		10,183
Corporate bonds	7,311		9,186
Corporate equity securities	0		0
Total	21,353		19,369
Liabilities [Abstract]
Liabilities			0
Foreign currency hedge obligations	0
Recurring [Member] | Significant Other Observable Inputs (Level 3) [Member]
Cash Equivalents and Investments [Abstract]
Money market fund			0
Certificates of deposit	0		0
Corporate bonds	0		0
Corporate equity securities	0		0
Total	0		0
Liabilities [Abstract]
Liabilities			0
Foreign currency hedge obligations	$2
[1]	Certificate of deposit with original maturities of less than 90 days.

Inventories_Details

Inventories (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Inventories [Abstract]
Raw materials	$19,688,000	$18,990,000
Work in process	16,948,000	16,222,000
Finished goods	2,839,000	3,362,000
Inventories, total	39,475,000	38,574,000
Inventory reserve	$11,400,000	$11,200,000

Accrued_Liabilities_Details

Accrued Liabilities (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Components of accrued liabilities [Abstract]
Accrued product warranty	$392	$802
Accrued compensation and related charges	1,718	2,656
Current portion of royalty payments	744	800
Dividends payable by consolidated joint ventures	646	563	729
Accrued professional services	304	509
Accrued income taxes	110	119
Other accrued liabilities	1,901	2,185
Accrued liabilities, total	$5,815	$7,634

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	0 Months Ended	3 Months Ended
	Aug. 31, 2011	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
		Installment
Related Party Transaction [Line Items]
Related party notes receivable - long term		$1,710,000		$1,704,000
Maturity date	31-Dec-16
Accounts payable		9,131,000		7,137,000
Accounts receivable		18,787,000		17,864,000
Area of leased property (in square feet)		19,467
Principal and interest on loan		173,000		171,000
Beijing JiYa Semiconductor Material Co Ltd [Member]
Related Party Transaction [Line Items]
Amount of loan under note agreement	1,700,000
Number of equity method investees to whom loan was granted	1
Term of loan		2 years 10 months
Number of installments		3
Related party notes receivable - long term		1,700,000		1,700,000
Income from agency sales		1,000	5,000
Accounts payable		1,800,000		1,800,000
Accounts receivable		350,000		350,000
Beijing Tongmei Xtal Technology [Member]
Related Party Transaction [Line Items]
Accounts payable		465,000		513,000
Area of leased property (in square feet)		22,081
Lease term		10 years
Annual lease payment		24,000
Increase in annual lease payment at each third year anniversary (in hundredths)		5.00%
Payments to purchase materials		121,000
Additional loan paid to related party		49,000
Interest on loan (in hundredths)		6.15%
Principal and interest on loan		52,000
Beijing Kaide Quartz Co. Ltd [Member]
Related Party Transaction [Line Items]
Accounts payable		$637,000		$730,000

Investments_in_Privatelyheld_C2

Investments in Privately-held Companies (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Summary of investments [Abstract]
Income allocated to minority interests	$125,000	$205,000
Equity investments classified as other assets	15,128,000		14,975,000
Investments in unconsolidated privately-held entities, included in other assets	200,000		200,000
AXT, Inc. [Member]
Summary of investments [Abstract]
Gross equity earnings (losses) from minority-owned joint ventures that are not consolidated, recorded as other income	957,000	2,119,000
Equity Method Investments [Member]
Summary of investments [Abstract]
Equity method investment by parent	8,147,000		8,095,000
Number of equity investment entities	3		3
Equity investments classified as other assets	8,100,000		8,100,000
Gross equity earnings (losses) from minority-owned joint ventures that are not consolidated, recorded as other income	200,000	487,000
Joint Ventures [Member]
Summary of investments [Abstract]
Number of consolidated joint ventures	3
Income from three consolidated joint ventures	600,000	800,000
Income allocated to minority interests	125,000	205,000
Net income from joint ventures attributable to parent	427,000	548,000
Minority investment in consolidated joint venture, included in other assets	4,300,000		4,000,000
Majority-Owned Subsidiaries [Member]
Summary of investments [Abstract]
Investments, consolidated	5,269,000		5,269,000
Beijing JiYa Semiconductor Material Co., Ltd [Member] | Majority-Owned Subsidiaries [Member]
Summary of investments [Abstract]
Investments, consolidated	3,331,000		3,331,000
Percentage of ownership, consolidated method (in hundredths)	46.00%
Nanjing Jin Mei Gallium Co., Ltd [Member] | Majority-Owned Subsidiaries [Member]
Summary of investments [Abstract]
Investments, consolidated	592,000		592,000
Percentage of ownership, consolidated method (in hundredths)	83.00%
Beijing BoYu Semiconductor Vessel Craftwork Technology Co., Ltd [Member] | Majority-Owned Subsidiaries [Member]
Summary of investments [Abstract]
Investments, consolidated	1,346,000		1,346,000
Percentage of ownership, consolidated method (in hundredths)	70.00%
Donghai County Dongfang High Purity Electronic Materials Co., Ltd [Member] | Equity Method Investments [Member]
Summary of investments [Abstract]
Equity method investment by parent	1,682,000		1,723,000
Percentage of ownership, equity method (in hundredths)	46.00%
Xilingol Tongli Germanium Co. Ltd [Member] | Equity Method Investments [Member]
Summary of investments [Abstract]
Equity method investment by parent	5,440,000		5,351,000
Percentage of ownership, equity method (in hundredths)	25.00%
Emeishan Jia Mei High Purity Metals Co., Ltd [Member] | Equity Method Investments [Member]
Summary of investments [Abstract]
Equity method investment by parent	$1,025,000		$1,021,000
Percentage of ownership, equity method (in hundredths)	25.00%

Investments_in_Privatelyheld_C3

Investments in Privately-held Companies, Minority Investment Entities (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
AXT, Inc. [Member]
Summarized income information of all the minority investment entities that are not consolidated and accounted for under the equity method [Abstract]
Revenue	$9,325,000	$13,480,000
Gross profit	2,295,000	3,963,000
Operating income	1,051,000	2,664,000
Net income	957,000	2,119,000
Equity Method Investments [Member]
Summarized income information of all the minority investment entities that are not consolidated and accounted for under the equity method [Abstract]
Net income	$200,000	$487,000

Stockholders_Equity_and_Stock_2

Stockholders' Equity and Stock Repurchase Program (Details) (USD $)	0 Months Ended	3 Months Ended		12 Months Ended
	Oct. 27, 2014	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period		$144,688,000
Common stock options exercised		76,000
Common stock repurchased		-617,000
Stock-based compensation		274,000
Net (loss) income		-899,000	-1,835,000
Dividends declared by joint ventures		-83,000
Change in unrealized (loss) gain on marketable securities		-259,000	-10,000
Currency translation adjustment		238,000
Balance, end of period		143,418,000
Stock Repurchase Program [Abstract]
Stock repurchase program, authorized amount	5,000,000	6,000,000
Shares repurchased (in shares)		230,000		285,000
Average price of shares repurchased (in dollars per share)		$2.67		$2.51
Total purchase price		617,000		716,000
Stock repurchase program remaining authorized repurchase amount		4,400,000		5,300,000
Preferred Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period					3,532,000
Balance, end of period		3,532,000			3,532,000
Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period					32,000
Balance, end of period		32,000			32,000
Additional Paid In Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period		195,419,000
Common stock options exercised		76,000
Common stock repurchased		-617,000
Stock-based compensation		274,000
Balance, end of period		195,152,000
Accumulated Deficit [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period		-68,393,000
Net (loss) income		-1,024,000
Balance, end of period		-69,417,000
Other Comprehensive Income/(Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period		7,673,000
Change in unrealized (loss) gain on marketable securities		-259,000
Currency translation adjustment		206,000
Balance, end of period		7,620,000
AXT, Inc. Stockholders' Equity [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period		138,263,000
Common stock options exercised		76,000
Common stock repurchased		-617,000
Stock-based compensation		274,000
Net (loss) income		-1,000
Change in unrealized (loss) gain on marketable securities		-259,000
Currency translation adjustment		206,000
Balance, end of period		136,919,000
Noncontrolling Interests [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period		6,425,000
Net (loss) income		125,000
Dividends declared by joint ventures		-83,000
Currency translation adjustment		32,000
Balance, end of period		$6,499,000

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	3 Months Ended		12 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Stock-based compensation in the form of employee stock options and restricted stock [Abstract]
Total stock-based compensation	$274,000	$292,000
Tax effect on stock-based compensation	0	0
Net effect on net income (loss)	274,000	292,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs related to unvested stock options not yet recognized	1,400,000
Value of estimated forfeitures	54,000
Weighted-average period of amortization	2 years 8 months 12 days
Number of options outstanding [Roll Forward]
Options outstanding, beginning of period (in shares)	3,198
Granted (in shares)	0
Exercised (in shares)	-54
Canceled and expired (in shares)	-29
Options outstanding, end of period (in shares)	3,115		3,198
Options vested and expected to vest as of March 31, 2015	3,115
Options exercisable as of March 31, 2015	1,885
Weighted average exercise price [Roll Forward]
Options outstanding, beginning of period (in dollars per share)	$3.12
Granted (in dollars per share)	$0
Exercised (in dollars per share)	$1.40
Canceled and expired (in dollars per share)	$2.74
Options outstanding, end of period (in dollars per share)	$3.16		$3.12
Options vested and expected to vest as of March 31, 2015	$3.16
Options exercisable as of March 31, 2015	$3.51
Weighted average Remaining Contractual Life [Abstract]
Options outstanding, beginning of period	6 years 8 months 19 days		6 years 11 months 12 days
Options outstanding, end of period	6 years 8 months 19 days		6 years 11 months 12 days
Options vested and expected to vest, end of period	6 years 8 months 19 days
Option exercisable, end of period	5 years 4 months 6 days
Aggregate Intrinsic Value [Abstract]
Options outstanding, beginning of period	1,247,000
Options outstanding, end of period	966,000		1,247,000
Options vested and expected to vest, end of period	966,000
Options exercisable, end of period	667,000
Closing price (in dollars per share)	$2.69
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average period of amortization	2 years 2 months 12 days
Shares [Roll Forward]
Non-vested, beginning of period (in shares)	261
Granted (in shares)	0
Vested (in shares)	0
Non-vested, end of period (in shares)	261
Weighted Average Grant Date Fair Value [Roll Forward]
Non-vested, beginning of period (in dollars per share)	$2.71
Granted (in dollars per share)	$0
Vested (in dollars per share)	$0
Non-vested, end of period (in dollars per share)	$2.71
Unrecognized compensation expense related to restricted stock awards	511,000
Cost of Revenue [Member]
Stock-based compensation in the form of employee stock options and restricted stock [Abstract]
Total stock-based compensation	5,000	5,000
Selling, General and Administrative [Member]
Stock-based compensation in the form of employee stock options and restricted stock [Abstract]
Total stock-based compensation	225,000	244,000
Research and Development [Member]
Stock-based compensation in the form of employee stock options and restricted stock [Abstract]
Total stock-based compensation	$44,000	$43,000

Net_Income_loss_Per_Share_Deta

Net Income (loss) Per Share (Details) (USD $)	3 Months Ended		12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2014
Numerator: [Abstract]
Net loss attributable to AXT, Inc.	($1,024)	($2,040)
Less: Preferred stock dividends	-44	-44
Net loss available to common stockholders	-1,068	-2,084
Denominator: [Abstract]
Denominator for basic net loss per share - weighted average common shares	32,553	32,364
Effect Of Dilutive Securities On Earnings Per Share [Line Items]
Denominator for dilutive net loss per common share	32,553	32,364
Net loss attributable to AXT, Inc. per common share:
Basic (in dollars per share)	($0.03)	($0.06)
Diluted (in dollars per share)	($0.03)	($0.06)
Weighted-average shares: [Abstract]
Preferred stock, shares issued (in shares)	883			883
Preferred stock, shares outstanding (in shares)	883			883
Preferred stock, par value (in dollars per share)	$0.00			$0.00
Preferred stock, value	$3,532			$3,532
Cumulative annual dividend rate (in hundredths)	5.00%		5.00%
Liquidation preference over common stock (in dollars per share)	$4			$4
Options [Member]
Weighted-average shares: [Abstract]
Securities excluded from diluted net loss per share as the impact is anti-dilutive (in shares)	3,167	2,607
Restricted Stock Awards [Member]
Weighted-average shares: [Abstract]
Securities excluded from diluted net loss per share as the impact is anti-dilutive (in shares)	261	241
Common Stock Options [Member]
Effect Of Dilutive Securities On Earnings Per Share [Line Items]
Effect of dilutive securities (in shares)	0	0
Restricted Stock Awards [Member]
Effect Of Dilutive Securities On Earnings Per Share [Line Items]
Effect of dilutive securities (in shares)	0	0

Segment_Information_and_Foreig2

Segment Information and Foreign Operations, Revenue by product (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Segment Information and Foreign Operations [Abstract]
Revenue	$20,064	$19,345

Segment_Information_and_Foreig3

Segment Information and Foreign Operations (Details) (USD $)	3 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
	Segment		Customer
Segment Information [Abstract]
Number of operating segments	1
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Revenue	$20,064	$19,345
Long-lived assets by geographic region [Abstract]
Long-lived assets	33,223		33,862
Revenue [Member]
Revenue, Major Customer [Line Items]
Number of customers representing significant share	0	0
Accounts Receivable [Member]
Revenue, Major Customer [Line Items]
Number of customers representing significant share	0		2
Major Customer One [Member] | Accounts Receivable [Member]
Revenue, Major Customer [Line Items]
Percentage share generated by major customers (in hundredths)			11.00%
Major Customer Two [Member] | Accounts Receivable [Member]
Revenue, Major Customer [Line Items]
Percentage share generated by major customers (in hundredths)			10.00%
Top Five Major Customers [Member] | Revenue [Member]
Revenue, Major Customer [Line Items]
Number of customers representing significant share	5	5
Percentage share generated by major customers (in hundredths)	35.00%	39.00%
Europe (primarily Germany) [Member] | Reportable Geographical Components [Member]
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Revenue	4,943	6,583
China [Member] | Reportable Geographical Components [Member]
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Revenue	3,297	4,165
Long-lived assets by geographic region [Abstract]
Long-lived assets	32,820		33,726
Asia Pacific (excluding China, Japan and Taiwan) [Member] | Reportable Geographical Components [Member]
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Revenue	2,759	2,389
Taiwan [Member] | Reportable Geographical Components [Member]
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Revenue	3,109	2,115
Japan [Member] | Reportable Geographical Components [Member]
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Revenue	2,484	2,313
North America (primarily the United States) [Member] | Reportable Geographical Components [Member]
Net revenues reported for products shipped to customers in corresponding geographic region [Abstract]
Revenue	3,472	1,780
Long-lived assets by geographic region [Abstract]
Long-lived assets	$403		136

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
	sqft
Product Warranty [Abstract]
Period of warranty	12 months
Change in warranty accrual [Roll Forward]
Beginning accrued warranty and related costs	$802,000	$1,048,000
Accruals for warranties issued	174,000	496,000
Adjustments related to pre-existing warranties including expirations and changes in estimates	-294,000	-103,000
Cost of warranty repair	-290,000	-214,000
Ending accrued warranty and related costs	392,000	1,227,000
Leases [Abstract]
Area of property under long-term operating lease (in square feet)	19,467
Aggregate amount payable towards royalty	7,000,000
Term of royalty agreement	8 years
Outstanding contractual obligations [Abstract]
Total	690,000
Less than 1 year	236,000
1-3 years	289,000
4-5 years	54,000
More than 5 year	111,000
Other Commitments, Fiscal Year Maturity [Abstract]
Total	3,015,000
Less than 1 year	980,000
1-3 years	1,439,000
4-5 years	485,000
More than 5 years	111,000
Royalty Agreement [Member]
Other Commitments, Fiscal Year Maturity [Abstract]
Total	2,325,000
Less than 1 year	744,000
1-3 years	1,150,000
4-5 years	431,000
More than 5 years	$0

Foreign_Exchange_Transaction_G1

Foreign Exchange Transaction Gains/Losses (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Foreign Exchange Transaction Gains/Losses [Abstract]
Foreign exchange transaction exchange gains (losses)	$180,000	$17,000

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Taxes [Abstract]
Net operating losses or credits utilization period	1 year
Change in cumulative ownership percentage (in hundredths)	50.00%
Period with in which cumulative ownership change	3 years
Gross unrecognized tax benefits	$16,400,000
Unrecognized tax benefits interest and penalties	0
Unrecognized tax benefits accrued interest and penalties	0
Federal income tax benefit or expense	$0	$0

Restructuring_Charges_Details

Restructuring Charges (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
		Position
Restructuring Charges [Abstract]
Number of workforce reduced		93
Percentage of reduction in workforce (in hundredths)		11.00%
Restructuring charge	$0	$907

Whistleblower_Complaint_and_In1

Whistleblower Complaint and Investigation (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
Whistleblower Complaint and Investigation [Abstract]
Professional service fees	$1.80