3. Fair Value of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Assets:
Notes receivable	$ 651	$ 980
Liabilities:
Bank acceptance payable	1,445	1,271
Fair Value, Measurements, Recurring [Member]
Assets:
Cash and cash equivalents	9,909	32,175
Restricted cash	10,041	509
Short term investments	8,190	8,189
Notes receivable	651	980
Total assets	28,791	41,853
Liabilities:
Bank acceptance payable	1,445	1,271
Total liabilities	1,445	1,271
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets:
Cash and cash equivalents	9,909	32,175
Restricted cash	10,041	509
Short term investments	8,190	8,189
Notes receivable	0	0
Total assets	28,140	40,873
Liabilities:
Bank acceptance payable	0	0
Total liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets:
Cash and cash equivalents	0	0
Restricted cash	0	0
Short term investments	0	0
Notes receivable	651	980
Total assets	651	980
Liabilities:
Bank acceptance payable	1,445	1,271
Total liabilities	1,445	1,271
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets:
Cash and cash equivalents	0	0
Restricted cash	0	0
Short term investments	0	0
Notes receivable	0	0
Total assets	0	0
Liabilities:
Bank acceptance payable	0	0
Total liabilities	$ 0	$ 0