Annual report pursuant to Section 13 and 15(d)

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

v3.19.3
Employee Benefit Plans Employee Benefit Plans - Additional Information (Details) - USD ($)
 12 Months Ended
Aug. 31, 2019
Aug. 31, 2018
Aug. 31, 2017
Defined Benefit Plan Disclosure [Line Items]      
Deferred Compensation Arrangement with Individual, Compensation Expense $ 1,400,000 $ 1,500,000 $ 1,600,000
Fixed Income Securities      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage 70.00%    
Equity Securities      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage 30.00%    
Other Postretirement Benefit Plan, Defined Benefit      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year $ 200,000    
Defined Benefit Plan, Benefit Obligation $ 3,100,000 2,900,000  
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate 6.80%    
Defined Benefit Plan Health Care Cost Trend Rate In Future Period 5.00%    
Foreign Defined Benefit Plan, Net Periodic Benefit Cost $ 100,000 (100,000) (200,000)
Other Current Liabilities and Other Long-term Liabilities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Deferred Compensation Liability, Current and Noncurrent $ 18,400,000 20,100,000  
401(k) [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent 50.00%    
Maximum Percentage Of Core Contributions Made By Employer 3.00%    
Defined Contribution Plan, Employer Matching Contribution, Percent of Match 25.00%    
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay 6.00%    
Company Contributions $ 0.50    
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Amount $ 1    
Defined Contribution Plan, Employer Discretionary Contribution Amount 3.00%    
Defined Contribution Plan, Cost $ 2,700,000 3,100,000 3,200,000
Supplemental Executive Retirement Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Benefit Obligation 1,600,000 1,700,000  
Defined Contribution Plan, Cost $ 400,000 300,000 $ 300,000
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%    
UNITED STATES | Pension Plans, Defined Benefit      
Defined Benefit Plan Disclosure [Line Items]      
Accumulated Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Tax $ (16,100,000) $ (13,200,000)  
Defined Benefit Plan, Expected Amortization, Next Fiscal Year $ 1,200,000    
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate 2.90% 4.05% 3.60%
Defined Benefit Plan, Expected Long Term Rate Of Returns On Assets Assumption 4.60%    
Amount of benefits expected to be paid in fiscal 2020 $ 3,000,000    
Amount of benefits expected to be paid in fiscal 2021 3,000,000    
Amount of benefits expected to be paid in fiscal 2022 3,000,000    
Amount of benefits expected to be paid in, fiscal 2023 3,000,000    
Amount of benefits expected to be paid in, fiscal 2024 3,000,000    
Amount of benefits expected to be paid fiscal 2025 through fiscal 2027 14,500,000    
Defined Benefit Plan, Benefit Obligation 47,400,000 $ 43,280,000 $ 46,806,000
Foreign Defined Benefit Plan, Net Periodic Benefit Cost 476,000 92,000 (36,000)
Company Contributions $ 108,000 $ 108,000  
Foreign Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate   2.00%  
Foreign Plan [Member] | Pension Plans, Defined Benefit      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate 1.10%    
Defined Benefit Plan, Expected Long Term Rate Of Returns On Assets Assumption 4.20%    
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year $ 300,000    
Amount of benefits expected to be paid in fiscal 2020 200,000    
Amount of benefits expected to be paid in fiscal 2021 300,000    
Amount of benefits expected to be paid in fiscal 2022 400,000    
Amount of benefits expected to be paid in, fiscal 2023 300,000    
Amount of benefits expected to be paid fiscal 2025 through fiscal 2027 1,900,000    
Defined Benefit Plan, Benefit Obligation 15,103,000 $ 13,056,000 13,423,000
Foreign Defined Benefit Plan, Net Periodic Benefit Cost 504,000 607,000 $ 918,000
Company Contributions $ 374,000 $ 588,000