DEBT (Details) (USD $)
3 Months Ended 9 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Mar. 31, 2015
Mar. 31, 2014
Jun. 30, 2014
Jun. 30, 2012
Long-term debt disclosure            
Total debt $ 319,484,000   $ 319,484,000   $ 311,860,000  
Convertible notes due 2019, net            
Long-term debt disclosure            
Total debt 319,484,000   319,484,000   311,860,000  
Aggregate principal amount of convertible senior notes issued           370,000,000
Interest rate on convertible senior notes (as a percent)           2.875%
Interest expense recognized 5,600,000 5,400,000 16,500,000 16,000,000    
Revolving credit facility            
Long-term debt disclosure            
Maximum availability under the revolving credit facility 450,000,000   450,000,000      
Outstanding amount under credit facility $ 0   $ 0