DEBT (Details) (USD $)	3 Months Ended		6 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2013	Jun. 30, 2012
Long-term debt disclosure
Total debt, non-current	$ 306,983,000		$ 306,983,000		$ 302,263,000
Convertible notes due 2019, net
Long-term debt disclosure
Total debt, non-current	306,983,000		306,983,000		302,263,000
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	5,300,000	5,200,000	10,600,000	10,300,000
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
Revolving credit facility, description of interest rate basis			LIBOR
Revolving credit facility, basis spread on interest rate (as a percent)			1.75%