LETTERS OF CREDIT (Details) (USD $)	Jun. 30, 2013	Mar. 31, 2013
Credit facilities
Long-term restricted cash and investment, as determined by the expiration date of the underlying letters of credit	$ 859,000	$ 899,000
Standby letters of credit
Credit facilities
Outstanding Amount	28,845,000
Restricted cash and investment balance	15,314,000
Long-term restricted cash and investment, as determined by the expiration date of the underlying letters of credit	$ 859,000
Standby letters of credit | Minimum
Credit facilities
Percentage of outstanding amount that is cash secured	52.00%
Standby letters of credit | Maximum
Credit facilities
Percentage of outstanding amount that is cash secured	72.00%