NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 4) (USD $)	0 Months Ended					12 Months Ended
	May 07, 2013	Feb. 11, 2013	Nov. 05, 2012	Aug. 02, 2012	May 14, 2012	Mar. 31, 2013 Customer	Mar. 31, 2012 Customer	Mar. 31, 2011 Customer
Concentrations of credit risk
Number of major customers						2	1	3
Common Stock Dividends
Dividends declared per common share (in dollars per share)	$ 0.50	$ 0.50	$ 0.50	$ 0.50	$ 0.50	$ 2.00	$ 1.60	$ 1.20
Credit risk
Concentrations of credit risk
Number of major customers						2
Credit risk | U.S. government
Concentrations of credit risk
Number of major customers						1
Credit risk | International customer
Concentrations of credit risk
Number of major customers						1
Accounts receivable | Credit risk
Concentrations of credit risk
Percentage of concentration risk						51.00%