INVESTMENTS (Details) (USD $)	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Mar. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	$ 8,241,000		$ 8,253,000
Gross Unrealized Gain	35,000		41,000
Gross Unrealized (Loss)	0		0
Fair Value	8,276,000		8,294,000
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	33,765,000		36,837,000
Gross Unrecognized Gain	160,000		202,000
Gross Unrecognized (Loss)	(85,000)		(32,000)
Fair Value	33,840,000		37,007,000
Available-for-sale investments by stated maturities, amortized cost [Abstract]
Amortized Cost, Due in less than one year	665,000		670,000
Amortized Cost, Due in 1 to 4 years	7,576,000		7,583,000
Amortized Cost, Total investments	8,241,000		8,253,000
Available-for-sale investments by stated maturity, fair value [Abstract]
Fair Value, Due in less than one year	665,000		670,000
Fair Value, Due in 1 to 4 years	7,611,000		7,624,000
Fair Value, Total investments	8,276,000		8,294,000
Held-to-maturity investments by stated maturities, amortized cost [Abstract]
Amortized Cost, Due in less than one year	21,247,000		21,019,000
Amortized Cost, Due in 1 to 4 years	12,518,000		15,818,000
Amortized Cost, Total investments	33,765,000		36,837,000
Held-to-maturity investments by stated maturity, fair value [Abstract]
Fair Value, Due in less than one year	21,287,000		21,062,000
Fair Value, Due in 1 to 4 years	12,553,000		15,945,000
Fair Value, Total investments	33,840,000		37,007,000
Investments, Debt and Equity Securities [Abstract]
Other-than-temporary impairment	0	0
Unrealized gain (loss) on available-for-sale investments, net of related income taxes	21,000		25,000
Redemptions of investments	717,000	0
Certificates of deposit [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	3,341,000		844,000
Gross Unrecognized Gain	0		0
Gross Unrecognized (Loss)	(4,000)		0
Fair Value	3,337,000		844,000
Corporate bonds [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	23,230,000		23,072,000
Gross Unrecognized Gain	103,000		131,000
Gross Unrecognized (Loss)	(81,000)		(31,000)
Fair Value	23,252,000		23,172,000
Municipal bonds [Member]
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	7,194,000		12,921,000
Gross Unrecognized Gain	57,000		71,000
Gross Unrecognized (Loss)	0		(1,000)
Fair Value	7,251,000		12,991,000
Certificates of deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	1,245,000		1,245,000
Gross Unrealized Gain	4,000		2,000
Gross Unrealized (Loss)	0		0
Fair Value	1,249,000		1,247,000
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	6,042,000		6,047,000
Gross Unrealized Gain	30,000		38,000
Gross Unrealized (Loss)	0		0
Fair Value	6,072,000		6,085,000
Municipal bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	954,000		961,000
Gross Unrealized Gain	1,000		1,000
Gross Unrealized (Loss)	0		0
Fair Value	$ 955,000		$ 962,000