Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 28, 2017	Feb. 29, 2016	Feb. 28, 2017	Feb. 29, 2016	Aug. 31, 2016
Impaired Assets [Line Items]
Goodwill, Impairment Loss				$ 118,122
Goodwill	$ 509,078		$ 509,078		$ 519,276
Asset Impairment Charges	0	$ 186,511	0	186,511
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)				16,653
Impairment of Intangible Assets, Finite-lived				27,952
Tangible Asset Impairment Charges				23,784
Future Amortization Expense, Remainder of 2017	10,000		10,000
Future Amortization Expense, 2018	19,900		19,900
Future Amortization Expense, 2019	19,300		19,300
Future Amortization Expense, 2020	18,700		18,700
Future Amortization Expense, 2021	17,800		17,800
Future Amortization Expense, 2022	15,800		15,800
Future Amortization Expense, Thereafter	34,400		34,400
Energy
Impaired Assets [Line Items]
Goodwill	184,694		184,694		187,321
Asset Impairment Charges		140,900		140,900
Engineered Solutions
Impaired Assets [Line Items]
Goodwill	$ 224,516		$ 224,516		$ 230,216
Asset Impairment Charges		$ 45,700		45,700
Cortland [Domain]
Impaired Assets [Line Items]
Goodwill, Impairment Loss				34,502
Asset Impairment Charges				36,713
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)				2,211
Impairment of Intangible Assets, Finite-lived				0
Tangible Asset Impairment Charges				0
Viking [Domain]
Impaired Assets [Line Items]
Goodwill, Impairment Loss				39,099
Asset Impairment Charges				104,124
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)				13,289
Impairment of Intangible Assets, Finite-lived				27,952
Tangible Asset Impairment Charges				23,784
maximatecc [Domain]
Impaired Assets [Line Items]
Goodwill, Impairment Loss				44,521
Asset Impairment Charges				45,674
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)				1,153
Impairment of Intangible Assets, Finite-lived				0
Tangible Asset Impairment Charges				$ 0