Restructuring Charges (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 5,637	$ 6,273	$ 0
Restructuring charges	7,228	14,571	0
Restructuring Reserve, Cash Payments	(7,509)	(7,519)
Restructuring Reserve, Settled without Cash	(527)	(793)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	172	14
Industrial
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	202	1,343	0
Restructuring charges	1,687	3,158
Restructuring Reserve, Cash Payments	2,384	1,772
Restructuring Reserve, Settled without Cash	436	54
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	(8)	11
Energy
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	3,613	3,021	0
Restructuring charges	1,942	5,544
Restructuring Reserve, Cash Payments	1,460	2,345
Restructuring Reserve, Settled without Cash	41	166
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	151	(12)
Engineered Solutions
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1,792	1,863	0
Restructuring charges	3,488	5,411
Restructuring Reserve, Cash Payments	3,582	3,199
Restructuring Reserve, Settled without Cash	6	364
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	29	15
Corporate Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	30	46	$ 0
Restructuring charges	111	458
Restructuring Reserve, Cash Payments	83	203
Restructuring Reserve, Settled without Cash	44	209
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	$ 0	$ 0