Goodwill and Other Intangible Assets Goodwill by Segment (Details) $ in Thousands	6 Months Ended
	Feb. 28, 2017 USD ($)
Goodwill [Roll Forward]
Beginning Balance, Goodwill	$ 160,414
Effect of foreign currency translation adjustments	(284)
Other	(372)
Ending Balance, Goodwill	159,758
Energy [Member]
Goodwill [Roll Forward]
Beginning Balance, Goodwill	552
Effect of foreign currency translation adjustments	0
Other	0
Ending Balance, Goodwill	552
Ag [Member]
Goodwill [Roll Forward]
Beginning Balance, Goodwill	148,916
Effect of foreign currency translation adjustments	(284)
Other	0
Ending Balance, Goodwill	148,632
Corporate and Other
Goodwill [Roll Forward]
Beginning Balance, Goodwill	10,946
Effect of foreign currency translation adjustments	0
Other	(372)
Ending Balance, Goodwill	10,574
Nitrogen Production [Member]
Goodwill [Roll Forward]
Ending Balance, Goodwill	$ 0