Investments in Privately-held Companies, Minority Investment Entities (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
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	$ 13,480,000	$ 9,273,000
Gross profit	3,963,000	3,124,000
Operating income	2,664,000	1,614,000
Net income	2,119,000	1,295,000
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	$ 487,000	$ 282,000