6. FINANCIAL INSTRUMENTS - Available for sale investments (Details) - USD ($)	3 Months Ended
Jun. 30, 2016	Mar. 31, 2016
Available-for-sale investments
Cost	$ 31,080,000
Fair Value	$ 31,131,000
Other information
Maximum maturity period of investment portfolio	3 years
Deferred tax liability related to unrecognized gains and losses on short-term and long-term investments	$ 18,000	$ 14,000
Short-term investments
Available-for-sale investments
Cost	21,713,000	23,137,000
Gross Unrealized Gains	16,000	16,000
Gross Unrealized Losses	(2,000)	(3,000)
Fair Value	21,727,000	23,150,000
Short-term investments \| State and municipal obligations
Available-for-sale investments
Cost	1,000,000	1,011,000
Fair Value	1,000,000	1,011,000
Short-term investments \| Corporate notes
Available-for-sale investments
Cost	4,265,000	5,680,000
Gross Unrealized Losses	(2,000)	(3,000)
Fair Value	4,263,000	5,677,000
Short-term investments \| Certificates of deposits
Available-for-sale investments
Cost	11,750,000	11,750,000
Gross Unrealized Gains	14,000	12,000
Fair Value	11,764,000	11,762,000
Short-term investments \| Foreign government obligations
Available-for-sale investments
Cost	2,698,000	2,695,000
Gross Unrealized Gains	2,000	3,000
Fair Value	2,700,000	2,698,000
Short-term investments \| Agency bonds
Available-for-sale investments
Cost	2,000,000	2,001,000
Gross Unrealized Gains		1,000
Fair Value	2,000,000	2,002,000
Long-term investment
Available-for-sale investments
Cost	9,367,000	11,118,000
Gross Unrealized Gains	37,000	30,000
Gross Unrealized Losses		(1,000)
Fair Value	9,404,000	11,147,000
Long-term investment \| Corporate notes
Available-for-sale investments
Cost	558,000	558,000
Gross Unrealized Gains	2,000	1,000
Fair Value	560,000	559,000
Long-term investment \| Certificates of deposits
Available-for-sale investments
Cost	6,750,000	8,500,000
Gross Unrealized Gains	30,000	24,000
Gross Unrealized Losses		(1,000)
Fair Value	6,780,000	8,523,000
Long-term investment \| Foreign government obligations
Available-for-sale investments
Cost	1,059,000	1,060,000
Gross Unrealized Gains	1,000	1,000
Fair Value	1,060,000	1,061,000
Long-term investment \| Agency bonds
Available-for-sale investments
Cost	1,000,000	1,000,000
Gross Unrealized Gains	4,000	4,000
Fair Value	$ 1,004,000	$ 1,004,000

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- Definition

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

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- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

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- References

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- Definition

Amount of debt securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26610-111562

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 320
-Section 50
-Paragraph 2
-Subparagraph (b)-(g)
-URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803

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- Definition

Amount of deferred tax liability attributable to taxable temporary differences from investments (excludes investments in subsidiaries and equity method investments).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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