Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Capital Management and Dividends - Additional Information (Detail)

v3.4.0.3
Capital Management and Dividends - Additional Information (Detail)
AUD / shares in Units, $ / shares in Units, AUD in Millions, $ in Millions
 3 Months Ended 12 Months Ended
May. 19, 2016
$ / shares
Mar. 31, 2016
Sep. 30, 2015
USD ($)
$ / shares
shares
Sep. 30, 2015
AUD
AUD / shares
shares
Mar. 31, 2016
USD ($)
Mar. 31, 2015
USD ($)
Mar. 31, 2014
USD ($)
Dividends Payable [Line Items]              
Percentage of stock buyback program authorized   5.00%     5.00%    
Aggregate number of common stock repurchased and cancelled | shares     1,653,247 1,653,247      
Aggregate cost of common stock repurchased     $ 22.3 AUD 30.0 $ 22.3 $ 9.1 $ 22.1
Average price paid per share of common stock repurchased and cancelled | (per share)     $ 13.50 AUD 18.14      
Ordinary dividend record date   Jun. 09, 2016          
Ordinary dividend payment Date   Aug. 05, 2016          
Subsequent Event [Member]              
Dividends Payable [Line Items]              
Ordinary dividend declared | $ / shares $ 0.29            
Fiscal 2017 Program [Member]              
Dividends Payable [Line Items]              
Aggregate cost of common stock repurchased | $         $ 100.0