Common Stock Purchases - Additional Information (Detail) (USD $)
In Millions, except Per Share data, unless otherwise specified
1 Months Ended 3 Months Ended 9 Months Ended
Nov. 30, 2012
Apr. 06, 2013
Mar. 31, 2012
Apr. 06, 2013
Mar. 31, 2012
Common stock repurchase program, authorized amount $ 30        
Number of shares repurchased during the period   3.7 0 5.5 0
Common stock repurchased, average price per share   $ 3.88   $ 3.88  
Common stock repurchased, aggregate purchase price   $ 14.4   $ 21.2