Description of Business and Summary of Significant Accounting Policies (Summary of Changes in AOCI) (Details 4) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2016	Aug. 31, 2015	Aug. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (50,854)
Other comprehensive income (loss) before reclassifications	(28,741)
Amounts reclassified from AOCI	39,718
Total other comprehensive income (loss)	10,977	$ (137,816)	$ 5,714
Ending balance	(39,877)	(50,854)
Foreign currency translation adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	6,666
Other comprehensive income (loss) before reclassifications	9,672
Total other comprehensive income (loss)	9,672
Ending balance	16,338	6,666
Derivative instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(12,033)
Other comprehensive income (loss) before reclassifications	(18,994)
Amounts reclassified from AOCI	38,811
Total other comprehensive income (loss)	19,817
Ending balance	7,784	(12,033)
Actuarial loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(30,624)
Other comprehensive income (loss) before reclassifications	(14,009)
Amounts reclassified from AOCI	1,046
Total other comprehensive income (loss)	(12,963)
Ending balance	(43,587)	(30,624)
Prior service cost
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	1,054
Other comprehensive income (loss) before reclassifications	26
Amounts reclassified from AOCI	(139)
Total other comprehensive income (loss)	(113)
Ending balance	941	1,054
Unrealized loss on available for sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(15,917)
Other comprehensive income (loss) before reclassifications	(5,436)
Total other comprehensive income (loss)	(5,436)
Ending balance	$ (21,353)	$ (15,917)