STOCKHOLDERS' EQUITY (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended		180 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Aug. 18, 2016	Aug. 13, 2015
STOCKHOLDERS' EQUITY [Abstract]
Authorized number of shares under stock repurchase program (in shares)				500,000	500,000
Common stock repurchased during the period (in shares)	328,481		6,000,000
Average cost of share repurchased (in dollars per share)	$ 81.62		$ 24.44
Common stock repurchased during the period	$ 26.8		$ 147.3
Shares repurchased to satisfy tax withholding obligation (in shares)	29,736	30,447
Value of Shares repurchased to satisfy tax withholding obligation	$ 2.6	$ 2.5