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

Income Taxes - Additional Information (Detail)

v3.19.1
Income Taxes - Additional Information (Detail)
$ in Millions
 12 Months Ended 60 Months Ended
Mar. 31, 2019
USD ($)
Mar. 31, 2019
AUD ($)
Mar. 31, 2018
USD ($)
Mar. 31, 2017
USD ($)
Mar. 31, 2019
USD ($)
Mar. 31, 2019
AUD ($)
Apr. 01, 2018
USD ($)
Mar. 31, 2016
USD ($)
Tax Credit Carryforward [Line Items]                
Deferred income taxes $ 1,092,900,000   $ 29,900,000   $ 1,092,900,000      
Recognized tax deduction 86,900,000 $ 119.1            
Contribution to AICF 103,000,000   102,200,000 $ 91,100,000 472,100,000 $ 595.3    
Foreign tax credit carry-forwards 115,500,000   126,100,000   115,500,000      
Income taxes payable 38,600,000       38,600,000      
Income tax paid, net of refunds 26,300,000              
Total amount of unrecognized tax benefits 600,000   700,000 700,000 600,000     $ 700,000
Interest and penalties accrued 100,000.0   0 0 100,000.0     $ 0
Interest and penalties recognized income tax expense $ 100,000.0   0 $ 0        
Period for the amount of unrecognized tax benefits increase or decrease next twelve months next twelve months            
Deferred tax assets, valuation allowance $ 267,600,000   129,600,000   267,600,000      
Other assets 2,900,000   $ 4,700,000   2,900,000      
Foreign Tax Credit Carry-Forwards [Member]                
Tax Credit Carryforward [Line Items]                
Foreign tax credit carry-forwards 114,600,000       114,600,000      
Research tax credit carry-forwards $ 900,000       $ 900,000      
Percentage of valuation allowance against loss carry-forwards (as percent) 100.00%       100.00%      
Australia                
Tax Credit Carryforward [Line Items]                
Tax loss carry-forwards $ 23,700,000       $ 23,700,000      
North America                
Tax Credit Carryforward [Line Items]                
Tax loss carry-forwards 37,000,000       37,000,000      
Europe [Member]                
Tax Credit Carryforward [Line Items]                
Tax loss carry-forwards 9,200,000       9,200,000      
Tax loss carry-forwards available to offset future taxable income not subject to expiration 5,700,000       5,700,000      
Operating loss carry-forwards subject to expiration $ 3,500,000       $ 3,500,000      
Accounting Standards Update 2016-16 [Member]                
Tax Credit Carryforward [Line Items]                
Deferred income taxes             $ 1,313,000,000  
Deferred tax assets, valuation allowance             148,200,000  
Other assets             $ 4,500,000