Investments in Privately-held Companies (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Summary of investments [Abstract]
Income allocated to minority interests	$ 441,000	$ 1,317,000
Gross equity earnings (losses) from minority-owned joint ventures that are not consolidated, recorded as other income	282,000	154,000
Investments in unconsolidated privately-held entities, included in other assets	392,000		392,000
AXT, Inc. [Member]
Summarized income information of all the minority investment entities that are not consolidated and accounted for under the equity method [Abstract]
Net Sales	9,273,000	6,543,000
Gross profit	3,124,000	1,950,000
Operating income	1,614,000	862,000
Net income	1,295,000	742,000
Equity Method Investments [Member]
Summary of investments [Abstract]
Equity Method Investment by Parent	7,344,000		7,326,000
Number of consolidated joint ventures	3	3
Income from three consolidated joint ventures	1,300,000	2,600,000
Income allocated to minority interests	441,000	1,317,000
Net income from joint ventures attributable to parent	852,000	1,300,000
Number of equity investment entities	3
Minority investment invested by consolidated joint venture, included in other assets	2,200,000	2,000,000
Gross equity earnings (losses) from minority-owned joint ventures that are not consolidated, recorded as other income	282,000	154,000
Majority-owned Subsidiaries [Member]
Summary of investments [Abstract]
Investments, consolidated	4,333,000		4,333,000
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	410,000		410,000
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	2,011,000		2,038,000
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	4,279,000		4,246,000
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	$ 1,054,000		$ 1,042,000
Percentage of ownership, equity method (in hundredths)	25.00%