4. Investments (Details) - Corporate Bond Securities [Member] - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Short Term Investments [Member]
Schedule of Held-to-maturity Securities [Line Items]
Cost	$ 39	$ 44
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	39	44
Long Term Investments [Member]
Schedule of Held-to-maturity Securities [Line Items]
Cost	5,210	5,555
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	(30)
Fair Value	$ 5,211	$ 5,525

Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.6)
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