DEBT (Details) (USD $)	1 Months Ended	3 Months Ended	9 Months Ended
	Jun. 30, 2012	Mar. 31, 2013	Mar. 31, 2013
Long-term debt disclosure
Total debt, non-current	$ 293,248,000	$ 299,961,000	$ 299,961,000
Convertible notes due 2019, net
Long-term debt disclosure
Total debt, non-current	293,248,000	299,961,000	299,961,000
Aggregate principal amount of convertible senior notes issued	370,000,000
Interest rate on convertible senior notes (as a percent)		2.875%	2.875%
Interest expense recognized		5,200,000	15,500,000
Revolving credit facility
Long-term debt disclosure
Maximum availability under the revolving credit facility		350,000,000	350,000,000
Outstanding amount under credit facility		$ 0	$ 0
Leverage ratio, maximum			3.0