Derivatives - Additional Information (Detail) (USD $)
0 Months Ended 9 Months Ended 12 Months Ended 3 Months Ended 9 Months Ended
Sep. 30, 2013
Contract
Mar. 31, 2015
Jun. 30, 2014
Mar. 31, 2015
Mar. 31, 2014
Mar. 31, 2014
Derivative [Line Items]            
Fair Value Assets/(Liability) Net   $ 263,274,000 $ (21,283,000) $ 263,274,000    
Number of interest rate swap contracts 1          
Not Designated as Hedging Instrument [Member]            
Derivative [Line Items]            
Forward contracts, maturity period   October 2017        
Forward contracts maturing within 12 months   353,200,000 363,400,000      
Interest Rate Swap Contract [Member]            
Derivative [Line Items]            
Notional amount of interest rate derivatives 19,700,000          
Cash Flow Hedging [Member]            
Derivative [Line Items]            
Fair value of forward contracts   1,526,900,000 1,467,700,000 1,526,900,000    
Forward contracts, maturity period   June 2018        
Ineffectiveness recognized   2,200,000   200,000 700,000 1,900,000
Amount expected to be reclassified from AOCI to earnings within the next 12 months   108,400,000        
Recognized net gains related to the change in forward points   0   0 600,000 600,000
Cash Flow Hedging [Member] | Hedging Instruments [Member] | Designated as Hedging Instrument [Member]            
Derivative [Line Items]            
Fair Value Assets/(Liability) Net   259,613,000 (19,856,000) 259,613,000    
Economic Hedges, Gross [Member] | Designated as Hedging Instrument [Member]            
Derivative [Line Items]            
Fair Value Assets/(Liability) Net   $ 3,661,000 $ (1,427,000) $ 3,661,000    
Minimum [Member]            
Derivative [Line Items]            
Foreign exchange contracts maturity period, years   2 years        
Maximum [Member]            
Derivative [Line Items]            
Foreign exchange contracts maturity period, years   5 years