Quarterly report pursuant to Section 13 or 15(d)

Earnings per share - Additional Information (Detail)

v2.4.0.6
Earnings per share - Additional Information (Detail)
3 Months Ended 9 Months Ended
Mar. 31, 2012
Mar. 31, 2011
Mar. 31, 2012
Mar. 31, 2011
Earnings Per Share Disclosure [Line Items]        
Number of potentially dilutive stock option shares excluded from the calculation of earnings per share 222,000 69,000 222,000 70,000