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%