5. FINANCIAL INSTRUMENTS (Details 2) (USD $)	3 Months Ended
	Jun. 30, 2014	Mar. 31, 2014
Available-for-sale investments
Fair Value	$ 63,705,000
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	13,000	11,000
Short-term investments
Available-for-sale investments
Cost	40,640,000	39,386,000
Gross Unrealized Gains	20,000	26,000
Fair Value	40,660,000	39,412,000
Short-term investments | State and municipal obligations
Available-for-sale investments
Cost	11,602,000	8,336,000
Gross Unrealized Gains	5,000	4,000
Fair Value	11,607,000	8,340,000
Short-term investments | Corporate notes
Available-for-sale investments
Cost	5,013,000	5,023,000
Gross Unrealized Gains	8,000	12,000
Fair Value	5,021,000	5,035,000
Short-term investments | Agency bonds
Available-for-sale investments
Cost	3,523,000	3,523,000
Gross Unrealized Gains	2,000	2,000
Fair Value	3,525,000	3,525,000
Short-term investments | Certificates of deposits
Available-for-sale investments
Cost	14,499,000	14,997,000
Gross Unrealized Gains	5,000	6,000
Fair Value	14,504,000	15,003,000
Short-term investments | Other Debt Securities [Member]
Available-for-sale investments
Cost	6,003,000
Fair Value	6,003,000
Short-term investments | International government obligations
Available-for-sale investments
Cost		7,507,000
Gross Unrealized Gains		2,000
Fair Value		7,509,000
Long-term investment
Available-for-sale investments
Cost	23,013,000	28,800,000
Gross Unrealized Gains	39,000	26,000
Gross Unrealized Losses	(7,000)	(7,000)
Fair Value	23,045,000	28,819,000
Long-term investment | State and municipal obligations
Available-for-sale investments
Cost	3,946,000	8,227,000
Gross Unrealized Gains	10,000	10,000
Fair Value	3,956,000	8,237,000
Long-term investment | Corporate notes
Available-for-sale investments
Cost	6,385,000	6,392,000
Gross Unrealized Gains	22,000	16,000
Fair Value	6,407,000	6,408,000
Long-term investment | Agency bonds
Available-for-sale investments
Cost	2,009,000	2,011,000
Gross Unrealized Losses	(2,000)	(5,000)
Fair Value	2,007,000	2,006,000
Long-term investment | Certificates of deposits
Available-for-sale investments
Cost	9,000,000	10,500,000
Gross Unrealized Gains	7,000
Gross Unrealized Losses		(2,000)
Fair Value	9,007,000	10,498,000
Long-term investment | Other Debt Securities [Member]
Available-for-sale investments
Cost	1,673,000	1,670,000
Gross Unrealized Losses	(5,000)
Fair Value	$ 1,668,000	$ 1,670,000