Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans Employee Benefit Plans - Additional Information (Details)

v3.20.2
Employee Benefit Plans Employee Benefit Plans - Additional Information (Details) - USD ($)
1 Months Ended 12 Months Ended
Sep. 30, 2020
Aug. 31, 2020
Aug. 31, 2019
Aug. 31, 2018
Defined Benefit Plan Disclosure [Line Items]        
Deferred Compensation Arrangement with Individual, Compensation Expense   $ 1,100,000 $ 1,400,000 $ 1,500,000
Equity Securities        
Defined Benefit Plan Disclosure [Line Items]        
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage   30.00%    
Fixed Income Securities        
Defined Benefit Plan Disclosure [Line Items]        
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage   70.00%    
Other Postretirement Benefit Plan, Defined Benefit        
Defined Benefit Plan Disclosure [Line Items]        
Defined Benefit Plan, Benefit Obligation   $ 2,400,000 3,100,000  
Foreign Defined Benefit Plan, Net Periodic Benefit Cost   (300,000) (100,000) 100,000
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year   $ 200,000    
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate   6.50%    
Defined Benefit Plan Health Care Cost Trend Rate In Future Period   5.00%    
Other Current Liabilities and Other Long-term Liabilities [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Deferred Compensation Liability, Current and Noncurrent   $ 15,700,000 18,400,000  
401(k) [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay   8.00%    
Defined Contribution Plan, Cost   $ 1,400,000 2,700,000 3,100,000
Maximum Percentage Of Core Contributions Made By Employer   3.00%    
Defined Benefit Plan, Plan Assets, Contributions by Employer   $ 0.50    
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Amount   1    
Supplemental Executive Retirement Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined Benefit Plan, Benefit Obligation   1,300,000 1,600,000  
Defined Contribution Plan, Cost   300,000 400,000 300,000
Restoration Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined Contribution Plan, Cost     100,000 100,000
Domestic Plan Member        
Defined Benefit Plan Disclosure [Line Items]        
Amount of benefits expected to be paid in fiscal 2021   2,900,000    
Amount of benefits expected to be paid in fiscal 2022   3,000,000.0    
Amount of benefits expected to be paid in fiscal 2023   3,000,000.0    
Amount of benefits expected to be paid in, fiscal 2024   3,000,000.0    
Amount of benefits expected to be paid in, fiscal 2025   3,000,000.0    
Amount of benefits expected to be paid fiscal 2026 through fiscal 2031   14,700,000    
Defined Benefit Plan, Benefit Obligation   49,640,000 47,400,000 43,280,000
Foreign Defined Benefit Plan, Net Periodic Benefit Cost   $ 773,000 $ 476,000 $ 92,000
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate   2.40% 2.90% 4.05%
Accumulated Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Tax   $ (21,400,000) $ (16,100,000)  
Defined Benefit Plan, Expected Amortization, Next Fiscal Year   $ 1,300,000    
Defined Benefit Plan, Expected Long Term Rate Of Returns On Assets Assumption   4.20%    
Defined Benefit Plan, Plan Assets, Benefits Paid   $ 3,222,000 2,912,000  
Defined Benefit Plan, Plan Assets, Contributions by Employer   183,000 108,000  
Domestic Plan Member | Subsequent Event [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined Benefit Plan, Plan Assets, Benefits Paid $ 600,000      
Foreign Plan Member        
Defined Benefit Plan Disclosure [Line Items]        
Amount of benefits expected to be paid in fiscal 2021   400,000    
Amount of benefits expected to be paid in fiscal 2022   300,000    
Amount of benefits expected to be paid in fiscal 2023   300,000    
Amount of benefits expected to be paid in, fiscal 2024   300,000    
Amount of benefits expected to be paid fiscal 2026 through fiscal 2031   1,900,000    
Defined Benefit Plan, Benefit Obligation   14,297,000 15,103,000 $ 13,056,000
Foreign Defined Benefit Plan, Net Periodic Benefit Cost   $ (443,000) $ 504,000 $ 607,000
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate   1.40% 1.10%  
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year   $ 200,000    
Defined Benefit Plan, Expected Long Term Rate Of Returns On Assets Assumption   3.90%    
Defined Benefit Plan, Plan Assets, Benefits Paid   $ 300,000 $ 421,000  
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment   (1,687,000) (107,000)  
Defined Benefit Plan, Plan Assets, Contributions by Employer   323,000 $ 374,000  
Foreign Plan Member | Other Expense [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment   700,000    
Foreign Plan Member | Other Comprehensive Income (Loss) [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment   $ (1,000,000.0)    
Minimum | Supplemental Executive Retirement Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined Contribution Plan Employer Contribution Percentage   3.00%    
Maximum | Supplemental Executive Retirement Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined Contribution Plan Employer Contribution Percentage   6.00%