Investments - Additional Information (Detail) (USD $)
3 Months Ended 9 Months Ended
Apr. 06, 2013
Apr. 06, 2013
Jun. 30, 2012
Mar. 31, 2012
Schedule of Available-for-sale Securities [Line Items]        
Short term available for Sale securities $ 41,084,000 $ 41,084,000 $ 76,428,000 $ 79,926,000
Available for sale securities 58,621,000 58,621,000 60,002,000 64,410,000
Temporary impairment charge   6,900,000    
Percentage of Company's ARS portfolio 92.00% 92.00%    
Investment maturity date range year start 2018 2018    
Investments maturity date range year end 2042 2042    
Par value of action rate securities 0 22,400,000    
Long term auction rate securities gross [Member]
       
Schedule of Available-for-sale Securities [Line Items]        
Available for sale securities 45,600,000 45,600,000    
Municipal Bonds [Member]
       
Schedule of Available-for-sale Securities [Line Items]        
Percentage of Company's ARS portfolio 8.00% 8.00%    
Standard & Poor's, AAA Rating [Member]
       
Schedule of Available-for-sale Securities [Line Items]        
Company's ARS Percentage consist 20.00% 20.00% 27.00%  
Standard & Poor's, AA Rating [Member]
       
Schedule of Available-for-sale Securities [Line Items]        
Company's ARS Percentage consist 47.00% 47.00% 23.00%  
Standard & Poor's, A Rating [Member]
       
Schedule of Available-for-sale Securities [Line Items]        
Company's ARS Percentage consist     28.00%  
Standard & Poor's, BBB Rating [Member]
       
Schedule of Available-for-sale Securities [Line Items]        
Company's ARS Percentage consist 18.00% 18.00% 12.00%  
Standard & Poor's, CCC Rating [Member]
       
Schedule of Available-for-sale Securities [Line Items]        
Company's ARS Percentage consist 15.00% 15.00% 10.00%  
Treasury bills [Member]
       
Schedule of Available-for-sale Securities [Line Items]        
Short term available for Sale securities 12,000,000 12,000,000    
Available for sale securities 19,900,000 19,900,000    
Certificates of deposit [Member]
       
Schedule of Available-for-sale Securities [Line Items]        
Short term available for Sale securities 29,100,000 29,100,000    
Long term auction rate securities [Member]
       
Schedule of Available-for-sale Securities [Line Items]        
Available for sale securities $ 38,700,000 $ 38,700,000