XML 95 R79.htm IDEA: XBRL DOCUMENT v3.23.3
Income Taxes - Additional Information (Detail) - USD ($)
 12 Months Ended
Sep. 30, 2023
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2020
Income Taxes [Line Items]        
Net decrease in valuation allowances $ 9,297 $ 8,682,000    
Tax credits, net capital and operating loss carryforwards 591,626 516,270,000    
Tax credits, net capital and operating loss carryforwards having expiration date $ 85,347 $ 104,079,000    
Tax credit net capital and operating loss carryforwards expiration dates Through 2042 for $104,079 tax credit, net capital and operating loss carryforwards Through 2042 for $104,079 tax credit, net capital and operating loss carryforwards    
Gross unrecognized tax benefits $ 196,949,000 $ 213,031,000 $ 195,196,000 $ 168,186,000
Accrued income taxes payable for interest and penalties relating to unrecognized tax benefits 35,065,000 35,471,000    
Interest and penalties recognized in the statements of income, relating to unrecognized tax benefits (net of reversals) (2,253) 10,460,000    
Unrecognized deferred tax liability for undistributed earnings of foreign subsidiary due to indefinitely reinvestment 81,700,000 $ 59,000,000    
Fiscal Year 2024 [Member]        
Income Taxes [Line Items]        
Unrecognized Tax Benefits Reduce 51,566      
Expected decrease in unrecognized tax benefits within next 12 months due to lapse of statutes of limitations $ 13,028      
GUERNSEY        
Income Taxes [Line Items]        
Statutory Guernsey tax rate 0.00% 0.00% 0.00%  
Prepaid Expenses and Other Current Assets [Member]        
Income Taxes [Line Items]        
Tax receivable balance $ 44,531 $ 56,959