Annual report pursuant to Section 13 and 15(d)

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

v3.10.0.1
Employee Benefit Plans Employee Benefit Plans - Additional Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Aug. 31, 2016
Aug. 31, 2018
Aug. 31, 2017
Aug. 31, 2016
Defined Benefit Plan Disclosure [Line Items]        
Deferred Compensation Arrangement with Individual, Compensation Expense   $ 1,500 $ 1,600 $ 1,600
Other Postretirement Benefit Plan, Defined Benefit        
Defined Benefit Plan Disclosure [Line Items]        
Defined Benefit Plan, Benefit Obligation   2,900 3,800  
Foreign Defined Benefit Plan, Net Periodic Benefit Cost   100 200 0
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year   $ 200    
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate   7.00%    
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   $ 20,100 20,900  
Domestic Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Amount of benefits expected to be paid in fiscal 2019   3,000    
Amount of benefits expected to be paid in fiscal 2020   3,000    
Amount of benefits expected to be paid in fiscal 2021   2,900    
Amount of benefits expected to be paid in, fiscal 2022   2,900    
Amount of benefits expected to be paid in, fiscal 2023   2,900    
Amount of benefits expected to be paid fiscal 2024 through fiscal 2027   14,600    
Defined Benefit Plan, Benefit Obligation $ 50,409 43,280 46,806 50,409
Foreign Defined Benefit Plan, Net Periodic Benefit Cost   $ 92 $ (36) $ (190)
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate 3.45% 4.05% 3.60% 3.45%
Accumulated Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Tax   $ (13,200) $ (16,000)  
Defined Benefit Plan, Expected Amortization, Next Fiscal Year   $ 800    
Defined Benefit Plan, Expected Long Term Rate Of Returns On Assets Assumption   5.75%    
Foreign Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Amount of benefits expected to be paid in fiscal 2019   $ 300    
Amount of benefits expected to be paid in fiscal 2020   300    
Amount of benefits expected to be paid in fiscal 2021   400    
Amount of benefits expected to be paid in, fiscal 2022   500    
Amount of benefits expected to be paid in, fiscal 2023   400    
Amount of benefits expected to be paid fiscal 2024 through fiscal 2027   2,400    
Defined Benefit Plan, Benefit Obligation   13,936 14,645  
Foreign Defined Benefit Plan, Net Periodic Benefit Cost   $ 700 $ 1,000 $ 700
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate   2.20% 2.30%  
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year   $ 300    
Defined Benefit Plan, Expected Long Term Rate Of Returns On Assets Assumption   4.40%    
401(k) [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined Contribution Plan, Employer Matching Contribution, Percent of Match   25.00%    
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay   6.00%    
Defined Contribution Plan, Cost   $ 4,700 $ 4,700 4,400
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent   50.00%    
Maximum Percentage Of Core Contributions Made By Employer   3.00%    
Supplemental Executive Retirement Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Defined Benefit Plan, Benefit Obligation   $ 1,700 $ 1,600  
Defined Contribution Plan, Cost $ 300 $ 300   $ 300
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%