Income Taxes (Details) (USD $)	3 Months Ended	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Income from continuing operations before income taxes [Abstract]
United States		$ (196,289,000)	$ 54,304,000	$ 171,329,000
Foreign		(141,160,000)	(11,348,000)	9,476,000
Income (loss) from continuing operations before income taxes		(337,449,000)	42,956,000	180,805,000
Current [Abstract]
Federal		556,000	5,267,000	33,499,000
State		356,000	453,000	2,583,000
Foreign		764,000	(2,000)	82,000
Total current tax expense (benefit)		1,676,000	5,718,000	36,164,000
Deferred [Abstract]
Federal		(58,194,000)	13,166,000	19,164,000
State		(264,000)	(2,748,000)	383,000
Foreign		(644,000)	(2,097,000)	1,457,000
Total deferred tax expense (benefit)		(59,102,000)	8,321,000	21,004,000
Total income tax expense (benefit)		(57,426,000)	14,039,000	57,168,000
Reconciliation of the difference between the federal statutory rate and the Company's effective tax rate [Abstract]
Federal statutory rate		35.00%	35.00%	35.00%
State taxes, net of credits		1.20%	(5.70%)	0.70%
Foreign income taxed at different rates		(3.50%)	4.20%	(0.60%)
Section 199 deduction		0.50%	(0.30%)	(1.00%)
Non-deductible officers' compensation		(0.10%)	1.50%	0.30%
Noncontrolling interests		0.20%	(2.20%)	(1.00%)
Research and development credits		0.20%	(2.00%)	(0.50%)
Valuation allowance on deferred tax assets		(8.60%)	0.00%	0.00%
Non-deductible goodwill		(7.10%)	0.00%	0.00%
Foreign interest income		0.00%	0.70%	0.00%
Other		(0.80%)	1.50%	(1.30%)
Effective tax rate		17.00%	32.70%	31.60%
Valuation Allowance, Deferred Tax Asset, Change in Amount	29,000,000
Deferred tax assets [Abstract]
Environmental liabilities	12,390,000	12,390,000	11,165,000
Employee benefit accruals	9,378,000	9,378,000	9,784,000
State income tax and other	2,478,000	2,478,000	5,384,000
Net operating loss carryforwards	11,758,000	11,758,000	5,699,000
State credit carryforwards	5,360,000	5,360,000	4,374,000
Inventory valuation methods	1,390,000	1,390,000	1,560,000
Amortizable goodwill and other intangibles	38,820,000	38,820,000	0
Valuation allowance	(29,696,000)	(29,696,000)	(795,000)
Total deferred tax assets	51,878,000	51,878,000	37,171,000
Deferred tax liabilities [Abstract]
Amortizable goodwill and other intangibles	0	0	20,452,000
Accelerated depreciation and basis differences	68,609,000	68,609,000	90,544,000
Prepaid expense acceleration	2,418,000	2,418,000	2,365,000
Foreign currency translation adjustment	30,000	30,000	1,987,000
Total deferred tax liabilities	71,057,000	71,057,000	115,348,000
Net deferred tax liability	19,179,000	19,179,000	78,177,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, as of the beginning of the year		491,000	303,000	1,631,000
Reductions for tax positions of prior years		(31,000)	(143,000)	(75,000)
Settlements with tax authorities		0	0	(875,000)
Additions for tax positions of the current year		66,000	331,000	160,000
Reductions for lapse of statutes		0	0	(538,000)
Unrecognized tax benefits, as of the end of the year	526,000	526,000	491,000	303,000
Foreign Country
Deferred tax liabilities [Abstract]
Operating Loss Carryforwards	48,000,000	48,000,000
Foreign Country | Minimum
Deferred tax liabilities [Abstract]
Operating Loss Carryforwards, Expiration Dates		Aug. 31, 2014
Foreign Country | Maximum
Deferred tax liabilities [Abstract]
Operating Loss Carryforwards, Expiration Dates		Aug. 31, 2033
State and Local Jurisdiction | Minimum
Deferred tax liabilities [Abstract]
Tax Credit Carryforward, Expiration Date		Aug. 31, 2014
State and Local Jurisdiction | Maximum
Deferred tax liabilities [Abstract]
Tax Credit Carryforward, Expiration Date		Aug. 31, 2025
Deferred Tax Liabilities Correction
Reconciliation of the difference between the federal statutory rate and the Company's effective tax rate [Abstract]
Correction of error resulting in reduction of income tax expense				$ 3,000,000