Postretirement and Other Employee Benefits (Net Periodic Benefit Cost for Pension Plans) (Details 9) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2013
Postretirement and Other Employee Benefits [Abstract]
Service cost	$ 1,054	$ 1,225	$ 1,596
Interest cost	5,554	6,819	5,977
Expected long-term return on plan assets	(5,778)	(6,167)	(5,308)
Recognized actuarial loss	1,723	2,817	2,474
Net curtailment gain	(2,542)	(107)	(3,401)
Amortization of prior service cost	(147)	(198)	(184)
Net periodic benefit cost	$ (136)	$ 4,389	$ 1,154