DEBT (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Dec. 31, 2012	Mar. 31, 2012
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Description	0.55
Senior Notes Payable Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 680.0
Amount outstanding	492.7
Reference rate	LIBOR
Basis spread on variable rate (in hundredths)	3.00%
Debt instrument interest rate, minimum (in hundredths)	4.00%
Debt instrument effective interest rate (in hundredths)	4.30%	4.40%
Unused amount available	151.7
Line Of Credit Facility Additional Remaining Borrowing Capacity	$ 35.6
Commitment fee percentage (in hundredths)	0.40%	0.50%
Expiration date	Nov. 19, 2014