BASIS OF PRESENTATION - Additional Information (Detail) (New Tricare South Region Contract, USD $)	6 Months Ended
	Sep. 30, 2012
New Tricare South Region Contract
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
TRICARE Health care cost payments	$ 1,300,000,000
TRICARE Health care cost reimbursements	1,200,000,000
Difference between TRICARE health care costs payments and reimbursements	$ 65,000,000