Net Income Per Share (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Numerator:
Net income attributable to AXT, Inc	$ 1,930,000	$ 1,151,000	$ 2,595,000	$ 1,193,000
Less: Preferred stock dividends	(44,000)	(44,000)	(88,000)	(88,000)
Net income available to common stockholders	$ 1,886,000	$ 1,107,000	$ 2,507,000	$ 1,105,000
Denominator:
Denominator for basic net income per share - weighted average common shares (in shares)	38,306,000	32,020,000	36,238,000	32,011,000
Effect of dilutive securities:
Denominator for dilutive net income per common share (in shares)	39,706,000	32,451,000	37,645,000	32,354,000
Net income attributable to AXT, Inc. per common share:
Basic (in dollars per share)	$ 0.05	$ 0.03	$ 0.07	$ 0.03
Diluted (in dollars per share)	$ 0.05	$ 0.03	$ 0.07	$ 0.03
Preferred stock, shares issued (in shares)	883,000		883,000		883,000
Preferred stock, shares outstanding (in shares)	883,000		883,000		883,000
Preferred stock, par value (in dollars per share)	$ 0.001		$ 0.001		$ 0.001
Preferred stock, value	$ 3,532,000		$ 3,532,000		$ 3,532,000
Cumulative annual dividend rate (as a percent)			5.00%		5.00%
Liquidation preference over common stock (in dollars per share)	$ 4		$ 4		$ 4
Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from diluted net income (loss) per share as the impact is anti-dilutive (in shares)	622,000	1,343,000	617,000	2,551,000
Restricted Stock Awards [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from diluted net income (loss) per share as the impact is anti-dilutive (in shares)		19,000	5,000	10,000
Options [Member]
Effect of dilutive securities:
Effect of dilutive securities (in shares)	1,212,000	284,000	1,216,000	223,000
Restricted Stock Awards [Member]
Effect of dilutive securities:
Effect of dilutive securities (in shares)	188,000	147,000	191,000	120,000