Penford (PENX) 10-K 14 Nov 13 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Aug. 31, 2013	Nov. 05, 2013	Feb. 28, 2013
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Aug-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Trading Symbol	'PENX	'	'
Entity Registrant Name	'PENFORD CORP	'	'
Entity Central Index Key	'0000739608	'	'
Current Fiscal Year End Date	'--08-31	'	'
Entity Well-known Seasoned Issuer	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Filer Category	'Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	12,497,654	'
Entity Public Float	'	'	$120.30

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$221	$154
Trade accounts receivable, net	43,432	36,464
Inventories	33,992	43,672
Prepaid expenses	3,100	2,826
Material and supplies	4,634	3,980
Income tax receivable	188	188
Other	4,547	4,681
Total current assets	90,114	91,965
Property, plant and equipment, net	112,141	113,191
Restricted cash value of life insurance	7,837	7,858
Deferred tax assets	4,987	13,108
Other assets	1,248	1,612
Other intangible assets, net	313	467
Goodwill, net	7,978	7,978
Total assets	224,618	236,179
Current liabilities:	'	'
Cash overdraft, net	5,072	7,337
Current portion of long-term debt and capital lease obligations	231	458
Accounts payable	20,656	19,201
Short-term financing arrangements	1,474	905
Accrued liabilities	8,207	8,237
Total current liabilities	35,640	36,138
Long-term debt and capital lease obligations	72,739	84,004
Other postretirement benefits	16,596	19,707
Pension benefit liability	10,552	20,917
Other liabilities	6,198	6,563
Total liabilities	141,725	167,329
Commitments and contingencies	'	'
Shareholders' equity:	'	'
Common stock, par value $1.00 per share, authorized 29,000 shares, issued 14,479 shares in 2013 and 14,342 shares in 2012, including treasury shares	14,454	14,281
Additional paid-in capital	105,166	103,205
Retained earnings (deficit)	3,649	-286
Treasury stock, at cost, 1,981 shares	-32,757	-32,757
Accumulated other comprehensive loss	-7,619	-15,593
Total shareholders' equity	82,893	68,850
Total liabilities and shareholders' equity	$224,618	$236,179

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, except Per Share data, unless otherwise specified
Statement Of Financial Position [Abstract]	'	'
Common stock, par value	$1	$1
Common stock, shares authorized	29,000	29,000
Common stock, shares issued	14,479	14,342
Treasury stock, shares	1,981	1,981

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Income Statement [Abstract]	'	'	'
Sales	$467,250	$433,151	$373,763
Cost of sales	422,203	389,241	339,928
Gross margin	45,047	43,910	33,835
Operating expenses	29,773	28,013	24,618
Research and development expenses	5,870	5,838	4,772
Income from operations	9,404	10,059	4,445
Interest expense	-3,989	-8,633	-9,364
Other non-operating income (expense), net	75	-6,186	115
Income (loss) before income taxes	5,490	-4,760	-4,804
Income tax expense (benefit)	1,483	4,806	313
Net income (loss)	$4,007	($9,566)	($5,117)
Weighted average common shares and equivalents outstanding:	'	'	'
Basic	12,369,487	12,293,749	12,250,914
Diluted	12,618,158	12,293,749	12,250,914
Earnings (loss) per common share:	'	'	'
Basic	$0.32	($0.78)	($0.42)
Diluted	$0.32	($0.78)	($0.42)
Dividends declared per common share	'	'	'

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Statement Of Income And Comprehensive Income [Abstract]	'	'	'
Net income (loss)	$4,007	($9,566)	($5,117)
Other comprehensive income (loss):	'	'	'
Change in fair value of derivatives, net of tax benefit (expense) of $(457), $(1,419) and $3,690	747	2,315	-6,018
Loss (gain) from derivative transactions reclassified into earnings from other comprehensive income, net of tax benefit (expense) of $(1,987), $(863) and $4,494	-3,241	-1,408	7,331
Actuarial gain (loss) on postretirement liabilities, net of tax benefit (expense) of $(5,547), $5,722 and $(2,450)	9,049	-9,336	3,997
Loss from postretirement liabilities reclassified to earnings, net of tax benefit of $869, $242 and $601	1,419	395	981
Other comprehensive income (loss)	7,974	-8,034	6,291
Total comprehensive income (loss)	$11,981	($17,600)	$1,174

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Statement Of Income And Comprehensive Income [Abstract]	'	'	'
Change in fair value of derivatives, tax	($457)	($1,419)	$3,690
Loss (gain) from derivative transactions reclassified into earnings from other comprehensive income, tax	-1,987	-863	4,494
Actuarial gain (loss) on post-retirement liabilities, tax	-5,547	5,722	-2,450
Loss from postretirement liabilities, tax	$869	$242	$601

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Operating activities:	'	'	'
Net income (loss)	$4,007	($9,566)	($5,117)
Adjustments to reconcile net income (loss) to net cash provided by operations:	'	'	'
Depreciation and amortization	13,326	14,127	14,415
Loss on redemption of Series A Preferred Stock	'	6,599	'
Non-cash interest on Series A Preferred Stock	'	'	3,859
Stock-based compensation	1,404	1,387	1,117
Loss on sale and disposal of assets	22	26	6
Deferred income tax expense	1,825	4,965	142
Non-cash loss (gain) on hedging transactions	3,543	-176	-1,620
Excess tax benefit from stock-based compensation	-16	'	'
Other	'	20	'
Change in operating assets and liabilities:	'	'	'
Trade accounts receivable	-7,063	-4,450	-2,769
Inventories	6,137	-6,460	-11,264
Decrease (increase) in margin accounts	-5,088	2,285	1,975
Prepaid expenses	-274	-536	-754
Accounts payable and accrued liabilities	1,808	2,105	2,250
Pension and other postretirement benefit contributions	-1,687	-4,574	-6,913
Pension and other postretirement benefit plan costs	5,107	3,386	4,905
Other receivables	2,554	-744	-490
Income tax receivable	'	-96	3,557
Payment of interest on Series A Preferred Stock, net	'	-5,311	'
Other	-956	-427	229
Net cash flow provided by operating activities	24,649	2,560	3,528
Investing activities:	'	'	'
Acquisitions of property, plant and equipment, net	-14,199	-14,146	-8,295
Acquisition of Carolina Starches, net of cash acquired	'	-8,347	'
Settlement of ethanol construction claim (Note 21)	2,106	'	'
Other	31	75	42
Net cash used in investing activities	-12,062	-22,418	-8,253
Financing activities:	'	'	'
Proceeds from revolving line of credit	22,200	88,706	38,550
Payments on revolving line of credit	-33,300	-28,200	-35,350
Payments on long-term debt	-200	-200	-200
Redemption of Series A preferred stock	'	-40,000	'
Payments on capital lease obligations	-280	-249	-253
Payment of loan fees	'	-973	'
Proceeds from financing arrangements	2,019	2,255	1,711
Payments on financing arrangements	-1,438	-2,050	-2,324
Exercise of stock options	730	'	'
Excess tax benefit from stock-based compensation	16	'	'
Increase (decrease) in cash overdraft	-2,265	434	2,518
Other	-2	8	39
Net cash provided by (used in) financing activities	-12,520	19,731	4,691
Increase (decrease) in cash and cash equivalents	67	-127	-34
Cash and cash equivalents, beginning of year	154	281	315
Cash and cash equivalents, end of year	221	154	281
Supplemental disclosure of cash flow information:	'	'	'
Interest	3,623	12,481	3,815
Income taxes paid (refunded), net	125	260	-3,373
Noncash investing and financing activities:	'	'	'
Capital lease obligations incurred for certain equipment leases	$88	$152	$10

Consolidated_Statements_of_Sha

Consolidated Statements of Shareholders' Equity (USD $)	Total	Common Stock [Member]	Preferred Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
In Thousands
Balance, beginning of year at Aug. 31, 2010	'	$13,190	$100	$102,303	$14,586	($13,850)
Treasury stock	-32,757	'	'	'	'	'
Tax deficiency on stock option and awards	'	'	'	-297	'	'
Change in fair value of derivatives, net of tax	-6,018	'	'	'	'	-6,018
Net income (loss)	-5,117	'	'	'	-5,117	'
Stock based compensation	'	'	'	1,117	'	'
Loss (gain) from derivative transactions reclassified into earnings from other comprehensive income, net of tax	7,331	'	'	'	'	7,331
Other	'	'	'	'	-101	'
Net (increase) decrease in postretirement liabilities, net of tax	'	'	'	'	'	4,978
Issuance of restricted stock, net	'	53	'	-53	'	'
Series B preferred stock converted to common shares	'	'	'	'	'	'
Total shareholders' equity	85,465	'	'	'	'	'
Balance, end of year at Aug. 31, 2011	'	13,243	100	103,070	9,368	-7,559
Treasury stock	-32,757	'	'	'	'	'
Tax deficiency on stock option and awards	'	'	'	-314	'	'
Change in fair value of derivatives, net of tax	2,315	'	'	'	'	2,315
Net income (loss)	-9,566	'	'	'	-9,566	'
Stock based compensation	'	'	'	1,387	'	'
Loss (gain) from derivative transactions reclassified into earnings from other comprehensive income, net of tax	-1,408	'	'	'	'	-1,408
Other	'	'	'	'	-88	'
Net (increase) decrease in postretirement liabilities, net of tax	'	'	'	'	'	-8,941
Issuance of restricted stock, net	'	38	'	-38	'	'
Series B preferred stock converted to common shares	'	1,000	-100	-900	'	'
Total shareholders' equity	68,850	'	'	'	'	'
Balance, end of year at Aug. 31, 2012	'	14,281	'	103,205	-286	-15,593
Treasury stock	-32,757	'	'	'	'	'
Tax deficiency on stock option and awards	'	'	'	'	'	'
Change in fair value of derivatives, net of tax	747	'	'	'	'	747
Net income (loss)	4,007	'	'	'	4,007	'
Stock based compensation	'	'	'	1,404	'	'
Loss (gain) from derivative transactions reclassified into earnings from other comprehensive income, net of tax	-3,241	'	'	'	'	-3,241
Other	'	'	'	'	-72	'
Exercise of stock options	'	121	'	609	'	'
Net (increase) decrease in postretirement liabilities, net of tax	'	'	'	'	'	10,468
Issuance of restricted stock, net	'	52	'	-52	'	'
Series B preferred stock converted to common shares	'	'	'	'	'	'
Total shareholders' equity	82,893	'	'	'	'	'
Balance, end of year at Aug. 31, 2013	'	$14,454	'	$105,166	$3,649	($7,619)

Business

Business	12 Months Ended
	Aug. 31, 2013
Accounting Policies [Abstract]	'
Business	'
	Note 1 — Business
	Penford Corporation (which, together with its subsidiary companies, is referred to herein as “Penford” or the “Company”) is a developer, manufacturer and marketer of specialty natural-based ingredient systems for food and industrial applications, including fuel grade ethanol. Penford’s products provide convenient and cost-effective solutions derived from renewable sources. Sales of the Company’s products are generated using a combination of direct sales and distributor agreements.
	The Company has significant research and development capabilities, which are used in applying the complex chemistry of carbohydrate-based materials and in developing applications to address customer needs. In addition, the Company has specialty processing capabilities for a variety of modified starches.
	Penford manages its business in two segments: Industrial Ingredients and Food Ingredients. These segments are based on broad categories of end-market users. The Food Ingredients segment produces specialty starches for food applications. The Industrial Ingredients segment is a supplier of specialty starches to the paper, packaging and other industries, and is a producer of fuel grade ethanol. The Industrial Ingredients segment also sells the by-products from its corn wet milling manufacturing operations, primarily germ, fiber and gluten to customers who use these by-products as animal feed or to produce corn oil.
	In January 2012, the Company completed the acquisition of the businesses operated by Carolina Starches, LLC and related entities (“Carolina Starches”) for $8.5 million in cash. Carolina Starches manufactures and markets cationic starches produced from potato, corn and tapioca. The acquisition of these businesses provides an important source of raw material to support continued growth in the Food Ingredients business and broadens the Company’s portfolio of specialty modified industrial starches. See Note 18.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Aug. 31, 2013
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	Note 2 — Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying consolidated financial statements include the accounts of Penford and its wholly owned subsidiaries. All material intercompany balances and transactions have been eliminated. Certain reclassifications have been made to prior years’ financial statements in order to conform to the current year presentation.
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Estimates are used in accounting for, among other things, the allowance for doubtful accounts, accruals, legal contingencies, the determination of fair value of net assets acquired in a business combination, the determination of assumptions for pension and postretirement employee benefit costs, useful lives of property and equipment, the assessment of a potential impairment of goodwill or long-lived assets, and income taxes including the determination of a need for a valuation allowance for deferred tax assets. Actual results may differ from previously estimated amounts.
	Cash and Cash Equivalents
	Cash and cash equivalents consist of cash and temporary investments with maturities of less than three months when purchased. Amounts are reported in the balance sheets at cost, which approximates fair value.
	Cash Overdrafts
	Cash overdrafts represent the amount by which outstanding checks issued, but not yet presented to banks for disbursement, exceed balances on deposit in the applicable bank accounts. The changes in cash overdrafts are included as a component of cash flows from financing activities in the consolidated statements of cash flows.
	Allowance for Doubtful Accounts and Concentration of Credit Risk
	The Company records accounts receivable at net realizable value, which includes an allowance for doubtful accounts to reflect any loss anticipated on the accounts receivable balances. The allowance for doubtful accounts reflects the Company’s best estimate of probable losses in the accounts receivable balances. Penford estimates the allowance for uncollectible accounts based on historical experience, known troubled accounts, industry trends, economic conditions, how recently payments have been received, and ongoing credit evaluations of its customers. Activity in the allowance for doubtful accounts for fiscal 2013, 2012 and 2011 is as follows (dollars in thousands):
		Balance		Charged to			Deductions			Balance
		Beginning of		Costs and			and Other			End of Year
		Year		Expenses
	Year ended August 31:
	2013	$	78	$	241		$	(39	)	$	280
	2012	$	1,305	$	(42	)	$	(1,185	)	$	78
	2011	$	350	$	958		$	(3	)	$	1,305
	Approximately 38%, 36% and 34% of the Company’s sales in fiscal 2013, 2012 and 2011, respectively, were made to customers who operate in the paper industry. This industry suffered an economic downturn, which has resulted in the closure of a number of mills. In fiscal 2011, the increase in the allowance for uncollectible accounts was related to two paper industry customers. These receivables were written off in fiscal 2012.
	Inventories
	Inventories are stated at the lower of cost or net realizable value. Costs are determined using the first-in, first-out (“FIFO”) method. Capitalized costs include materials, labor and manufacturing overhead related to the purchase and production of inventories.
	Property, Plant and Equipment
	The Company’s property consists primarily of plants and equipment used for manufacturing activities. Property, plant and equipment are recorded at cost less accumulated depreciation. Expenditures for maintenance and repairs are expensed as incurred. The Company uses the straight-line method to compute depreciation expense over the estimated useful lives of the depreciable assets. Equipment and vehicles generally have average useful lives ranging from three to twelve years and real estate between twelve to forty-six years. Depreciation, which includes depreciation of assets under capital leases, of $12.8 million, $12.7 million and $12.8 million was recorded in fiscal years 2013, 2012 and 2011, respectively. For income tax purposes, the Company generally uses accelerated depreciation methods.
	Interest is capitalized on major construction projects while in progress. During fiscal years 2013 and 2012, the Company capitalized $107,000 and $48,000, respectively, in interest costs. No interest was capitalized in fiscal 2011.
	The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Impairment is recognized when estimated expected undiscounted future cash flows are less than the carrying amount of the assets. To the extent that impairment has occurred, the excess of the carrying amount of long-lived assets over its estimated fair value would be recognized as an impairment loss charged to earnings.
	Goodwill and Other Intangible Assets
	Goodwill represents the excess of cost over the fair value of net assets acquired. The Company evaluates its goodwill for impairment annually as of June 1 and whenever events or circumstances make it more likely than not that impairment may have occurred. To determine whether goodwill is impaired, Penford compares the fair value of each reporting unit to that reporting unit’s carrying amount. If the fair value of the reporting unit is greater than its carrying amount goodwill is not considered impaired. If the fair value of the reporting unit is lower than its carrying amount, Penford then compares the implied fair value of the reporting unit’s goodwill with the carrying amount of that goodwill, and, if the carrying value is higher than the fair value, an impairment charge would be recorded. The implied fair value of a reporting unit is determined using a discounted cash flow method considering the Company’s market capitalization.
	Definite-lived intangible assets, primarily patents, are amortized using the straight-line method over their expected economic useful lives. At August 31, 2013, the weighted average remaining amortization period for patents is five years. Penford has no intangible assets with indefinite lives.
	Accrued Liabilities
	Components of accrued liabilities are as follows (dollars in thousands):
		August 31,
		2013		2012
	Employee-related costs	$	3,931	$	4,837
	Other		4,276		3,400
	Accrued liabilities	$	8,207	$	8,237
	Employee-related costs include accrued payroll, compensated absences, payroll taxes, benefits and incentives.
	Revenue Recognition
	Revenue from sales of products and shipping and handling revenue are recognized at the time goods are shipped and title transfers to the customer. This transfer is considered complete when a sales agreement is in place, delivery has occurred, pricing is fixed or determinable and collection is reasonably assured. Proceeds from the sale of by-products from the Company’s corn wet milling operations are classified as sales in the Statements of Operations. Costs associated with shipping and handling are included in cost of sales.
	Significant Customer and Export Sales
	The Company has several relatively large customers in each business segment. The Company’s sales of ethanol to its sole ethanol customer, Eco-Energy, Inc., represented approximately 21%, 24% and 28% of the Company’s net sales for fiscal years 2013, 2012 and 2011, respectively. Eco-Energy, Inc. is a marketer and distributor of biofuels in the United States and Canada, is a customer of the Company’s Industrial Ingredients business. Export sales accounted for approximately 8.0%, 7.6% and 7.2% of consolidated sales in fiscal years ended August 31, 2013, 2012 and 2011, respectively.
	Derivatives
	Penford uses derivative instruments to manage the exposures associated with commodity prices, interest rates and energy costs. The derivative instruments are reported at fair value in other current assets or current liabilities in the consolidated balance sheets. The Company offsets the fair value amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral arising from derivative instruments recognized at fair value executed with the same counterparty under a master netting arrangement.
	For derivative instruments designated and qualifying as fair value hedges, the gain or loss on the derivative instruments as well as the offsetting gain or loss on the hedged firm commitments or inventory are recognized in current earnings as a component of cost of goods sold. For derivative instruments designated and qualifying as cash flow hedges, the effective portion of the gain or loss on the derivative instruments is reported as a component of other comprehensive income (loss), net of applicable income taxes, and recognized in earnings when the hedged exposure affects earnings. The Company recognizes the gain or loss on the derivative instrument as a component of cost of goods sold in the period when the finished goods produced from the hedged item are sold or, for interest rate swaps, as a component of interest expense in the period the forecasted transaction is reported in earnings. If it is determined that the derivative instruments used are no longer effective at offsetting changes in cash flows or fair value of the hedged item, then the changes in fair value would be recognized in current earnings as a component of cost of good sold or interest expense.
	Research and Development
	Research and development costs are expensed as incurred, except for costs of patents, which are capitalized and amortized over the lives of the patents. The Company’s research and development expenditures primarily consists of internal salaries, wages, consulting and supplies attributable to time spent on research and development activities. Other costs include depreciation and maintenance of research and development facilities and equipment, including assets at manufacturing locations that are engaged in pilot plant activities. Research and development costs expensed were $5.9 million, $5.8 million and $4.8 million in fiscal 2013, 2012 and 2011, respectively.
	Stock-Based Compensation
	The Company has a long-term incentive plan that provides for stock-based compensation, including the granting of stock options and shares of restricted stock to employees and directors. The Company utilizes the Black-Scholes option-pricing model to determine the fair value of stock options on the date of grant. This model derives the fair value of stock options based on certain assumptions related to expected stock price volatility, expected option life, risk-free interest rate and dividend yield. The grant date fair value of restricted stock awards is equal to the market price of the Company’s common stock at the grant date.
	The Company recognizes stock-based compensation expense utilizing the accelerated multiple options approach over the requisite service period, which equals the vesting period. See Note 11 for further detail.
	Income Taxes
	The provision for income taxes includes federal and state taxes currently payable and deferred income taxes arising from temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured pursuant to tax laws using the rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The impact on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the date of enactment.
	A valuation allowance is provided to the extent that it is more likely than not that deferred tax assets will not be realized. Tax benefits from uncertain tax positions are recognized when it is more likely than not that the position will be sustained upon examination based on the technical merits of the position. The amount recognized is measured as the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon settlement. The Company recognizes interest and penalty expense associated with uncertain tax positions as a component of income tax expense.
	The Company has not provided deferred taxes related to its investment in foreign subsidiaries, which are classified as discontinued operations, as it does not expect future distributions from the subsidiaries or repayments of permanent advances.
	Foreign Currency
	Assets and liabilities of subsidiaries whose functional currency is deemed to be other than the U.S. dollar are translated at year end rates of exchange. Resulting translation adjustments are accumulated in the currency translation adjustments component of other comprehensive income. Statement of operations amounts are translated at average exchange rates prevailing during the year. Foreign currency transaction gains or losses in fiscal years 2013, 2012 and 2011 were not significant.
	Acquisitions
	Acquisitions of businesses are accounted for using the acquisition method of accounting and the financial statements include the results of the acquired operations from the date of acquisition. The purchase price of the acquired entity is allocated to the net assets acquired and net liabilities assumed based on the estimated fair value at the date of acquisition. The excess of cost over the fair value of the net assets acquired is recognized as goodwill.
	Recent Accounting Pronouncements
	In June 2011, the Financial Accounting Standards Board (“FASB”) issued guidance requiring entities to present the total of comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. The amendment did not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income under current accounting standards. The guidance was effective for the Company’s fiscal year and interim periods beginning September 1, 2012. The Company adopted this amended guidance in fiscal 2013 and presented the Consolidated Statements of Comprehensive Income (Loss) immediately following the Consolidated Statements of Operations.
	In February 2013, the FASB issued guidance requiring entities to provide information about the amounts reclassified out of accumulated other comprehensive income by component. Entities are required to present, either on the face of the financial statements or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income. This guidance, which is effective prospectively for annual reporting periods’ beginning after December 15, 2012, does not change the current requirements for reporting net income or other comprehensive income. The Company is evaluating the impact this guidance will have on its disclosures.
	In December 2011, the FASB issued guidance creating new disclosure requirements about the nature of an entity’s rights of setoff and related arrangements associated with its financial instruments and derivative instruments. The disclosure requirements are effective for annual reporting periods, and interim reporting periods within those years, beginning on or after January 1, 2013 (fiscal 2014 for Penford). The Company is evaluating the impact this update will have on its disclosures.
	In July 2013, the FASB issued guidance designed to reduce diversity in practice of financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. This guidance is effective for fiscal years, and interim reporting periods within those years, beginning after December 15, 2013 (fiscal 2015 for Penford). The Company does not expect this guidance to have a material effect on its financial position, results of operations or liquidity.

Inventories

Inventories	12 Months Ended
	Aug. 31, 2013
Inventory Disclosure [Abstract]	'
Inventories	'
	Note 3 — Inventories
	Components of inventory are as follows:
		August 31,
		2013		2012
		(Dollars in thousands)
	Raw materials	$	10,381	$	19,773
	Work in progress		1,913		1,542
	Finished goods		21,698		22,357
	Total inventories	$	33,992	$	43,672
	To reduce the price volatility of corn used in fulfilling some of its starch sales contracts, Penford, from time to time, uses readily marketable exchange-traded futures as well as forward cash corn purchases. The exchange-traded futures are not purchased or sold for trading or speculative purposes and are designated as hedges. See Note 14. General and administrative expenses are not capitalized as a component of inventory.

Property_and_equipment

Property and equipment	12 Months Ended
	Aug. 31, 2013
Property Plant And Equipment [Abstract]	'
Property and equipment	'
	Note 4 – Property and equipment
	Components of property and equipment are as follows:
		August 31,
		2013			2012
		(Dollars in thousands)
	Land and land improvements	$	11,881		$	11,623
	Plant and equipment		359,909			346,087
	Construction in progress		5,255			7,679
			377,045			365,389
	Accumulated depreciation		(264,904	)		(252,198	)
	Net property and equipment	$	112,141		$	113,191
	The above table includes approximately $0.8 million and $1.0 million of net property and equipment under capital leases for fiscal years 2013 and 2012, respectively. At August 31, 2013 and 2012, the Company had approximately $0.7 million and $1.1 million, respectively, of payables related to property, plant and equipment.

Goodwill_and_other_intangible_

Goodwill and other intangible assets	12 Months Ended
	Aug. 31, 2013
Goodwill And Intangible Assets Disclosure [Abstract]	'
Goodwill and other intangible assets	'
	Note 5 – Goodwill and other intangible assets
	The Company’s goodwill of $8.0 million at August 31, 2013 and 2012 relates to the Company’s Food Ingredients reporting unit. There were no additions to goodwill during fiscal 2013. See Note 18 for goodwill added in fiscal 2012 as a result of the acquisition of Carolina Starches. The Company completed its evaluation of the carrying value of goodwill as of June 1, 2013 and determined there was no impairment to the recorded value of goodwill. In order to identify potential impairments, Penford compared the fair value of its Food Ingredients reporting unit with its carrying amount, including goodwill. Penford then compared the implied fair value of goodwill with the carrying amount of that goodwill. The implied fair value of the reporting unit was determined using the discounted cash flow method, the implied market capitalization method and the guideline company method. The implied fair value of the reporting unit was computed using unobservable inputs and the fair value measurements are categorized as Level 3 in the fair value hierarchy. Since there was no indication of impairment, Penford was not required to complete the second step of the process which would measure the amount of any impairment. At June 1, 2013, the fair value of the Food Ingredients reporting unit was substantially in excess of its carrying value, and there are no changes in that conclusion as of August 31, 2013.
	Penford’s intangible assets consist of patents, customer lists and non-compete agreements. Patents are being amortized over the weighted average remaining amortization period of four years as of August 31, 2013. There is no residual value associated with patents. The fair value of customer lists and non-compete agreements from the acquisition of Carolina Starches are being amortized over their estimated useful lives. Customer lists are amortized on a straight-line basis over two years and the non-compete agreements are being amortized on a straight-line basis over the five-year term of the agreements. The carrying amount and accumulated amortization of intangible assets are as follows (dollars in thousands):
		August 31, 2013				August 31, 2012
		Carrying		Accumulated		Carrying		Accumulated
		Amount		Amortization		Amount		Amortization
	Intangible assets:
	Patents	$	1,748	$	1,538	$	1,748	$	1,500
	Customer lists		190		154		190		59
	Non-compete agreements		100		33		100		12
	Other intangible assets	$	2,038	$	1,725	$	2,038	$	1,571
	Amortization expense related to intangible assets was $0.1 million in each of the fiscal years 2013 and 2012 and less than $0.1 million in fiscal 2011. The estimated aggregate annual amortization expense for patents is not significant for the next five fiscal years, 2014 through 2018.

Preferred_Stock_Subject_to_Man

Preferred Stock Subject to Mandatory Redemption	12 Months Ended
	Aug. 31, 2013
Equity [Abstract]	'
Preferred Stock Subject to Mandatory Redemption	'
	Note 6 — Preferred Stock Subject to Mandatory Redemption
	On April 7, 2010, the Company issued $40 million of Series A 15% cumulative non-voting, non-convertible preferred stock (“Series A Preferred Stock”) and 100,000 shares of Series B voting convertible preferred stock (“Series B Preferred Stock”) in a private placement to Zell Credit Opportunities Master Fund, L.P., an investment fund managed by Equity Group Investments, a private investment firm (the “Investor”). The Company has 1,000,000 shares of authorized preferred stock, $1.00 par value, of which no shares are issued and outstanding as of August 31, 2013.
	The Company recorded the Series A Preferred Stock and the Series B Preferred Stock at their relative fair values at the time of issuance. The Series A Preferred Stock of $32.3 million was recorded as a long-term liability due to its mandatory redemption feature and the Series B Preferred Stock of $7.7 million was recorded as equity. The discount on the Series A Preferred Stock was amortized into income using the effective interest method over the contractual life of seven years. The holders of the Series A Preferred Stock were entitled to cash dividends of 6% on the sum of the outstanding Series A Preferred Stock plus accrued and unpaid dividends. In addition, dividends equal to 9% of the outstanding Series A Preferred Stock were accrued. Dividends on the Series A Preferred Stock and the discount accretion were recorded as interest expense in the consolidated statements of operations.
	In fiscal 2012, the Company redeemed $48.9 million of its Series A Preferred Stock. The Company redeemed 100,000 shares at the original issue price of $40.0 million plus accrued dividends of $8.9 million. As a result of the early redemption, the Company recorded accelerated discount accretion of $5.5 million and amortization of issuance costs of $1.1 million as a loss on redemption in other non-operating income (expense). In addition, in fiscal 2012, the Investor converted its 100,000 shares of Series B Preferred Stock into 1,000,000 shares of the Company’s common stock.

Debt

Debt	12 Months Ended
	Aug. 31, 2013
Debt Disclosure [Abstract]	'
Debt	'
	Note 7 — Debt
		August 31,
		2013		2012
		(Dollars in thousands)
	Secured credit agreements — revolving loans, 3.18% weighted average interest rate at August 31, 2013	$	71,506	$	82,606
	Iowa Department of Economic Development loans		1,233		1,433
	Capital lease obligations		231		423
			72,970		84,462
	Less: current portion and short-term borrowings		231		458
	Long-term debt and capital lease obligations	$	72,739	$	84,004
	In July 2012, in connection with the redemption of preferred stock discussed above, the Company refinanced its obligations then outstanding. The Company entered into a $130 million Fourth Amended and Restated Credit Agreement (the “2012 Agreement”) with Bank of Montreal; Cooperatieve Centrale Raiffeisen-Boerenleenbank B.A., “Rabobank Nederland” New York Branch; KeyBank National Association; JPMorgan Chase Bank N.A.; First Midwest Bank; Private Bank and Trust Company; Greenstone Farm Credit Services, ACA/FLCA and Bank of America, N.A. Under the 2012 Agreement, the Company may borrow $130 million in revolving lines of credit. The lenders’ revolving credit loan commitment may be increased under certain conditions. Under the 2012 Agreement, there are no scheduled principal payments prior to maturity on July 9, 2017.
	On August 31, 2013, the Company had $71.5 million outstanding under the 2012 Agreement, which is subject to variable interest rates. Interest rates under the 2012 Agreement are based on either the London Interbank Offered Rates (“LIBOR”) or the prime rate, depending on the selection of available borrowing options under the 2012 Agreement. Pursuant to the 2012 Agreement, the interest rate margin over LIBOR ranges between 2% and 4%, depending upon the Total Leverage Ratio (as defined).
	The 2012 Agreement provides that the Total Leverage Ratio, which is computed as funded debt divided by earnings before interest, taxes, depreciation and amortization (as defined in the 2012 Agreement) shall not exceed 3.50 through November 30, 2013; 3.25 through May 31, 2014; and 3.0 thereafter. In addition, the Company must maintain a Fixed Charge Coverage Ratio, as defined in the 2012 Agreement, of not less than 1.35. Fiscal 2014 annual capital expenditures will be restricted to $15 million if the Total Leverage Ratio is greater than 2.00 for the last two fiscal quarters. The Company’s obligations under the 2012 Agreement are secured by substantially all of the Company’s assets. The Company was in compliance with the covenants in the 2012 Agreement as of August 31, 2013.
	Pursuant to the 2012 Agreement, the Company may declare and pay dividends on its common stock in an amount not to exceed, in any consecutive four quarters, the lesser of $10 million or 50% of Free Cash Flow, as defined. As of August 31, 2013, the Company was not permitted to pay dividends.
	In fiscal 2010, the Iowa Department of Economic Development (“IDED”) awarded financial assistance to the Company as a result of the temporary shutdown of the Cedar Rapids, Iowa plant in the fourth quarter of fiscal 2008 due to record flooding of the Cedar River. The IDED provided two five-year non-interest bearing loans as follows: (1) a $1.0 million loan to be repaid in 60 equal monthly payments of $16,667 beginning December 1, 2009, and (2) a $1.0 million loan which is forgivable if the Company maintains certain levels of employment at the Cedar Rapids plant. At August 31, 2013, the Company had $1.2 million outstanding related to the IDED loans.
	The maturities of debt existing at August 31, 2013 for the fiscal years beginning with fiscal 2014 are as follows (dollars in thousands):
	2014	$	231
	2015		1,103
	2016		57
	2017		71,554
	2018		25
		$	72,970
	Included in the Company’s long-term debt at August 31, 2013 is $0.2 million of capital lease obligations, of which less than $0.1 million is considered current portion of long-term debt. See Note 10.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Aug. 31, 2013
Equity [Abstract]	'
Stockholders' Equity	'
	Note 8 — Stockholders’ Equity
	Common Stock
		Year Ended August 31,
		2013		2012		2011
	Common shares outstanding
	Balance, beginning of year		14,280,718		13,243,385		13,189,581
	Series B preferred stock converted to common shares		-		1,000,000		-
	Exercise of stock options		121,226		-		-
	Issuance of restricted stock, net		52,237		37,333		53,804
	Balance, end of year		14,454,181		14,280,718		13,243,385
	Preferred Stock, Series B
	In fiscal 2012, the Investor converted its 100,000 shares of Series B Preferred Stock into 1,000,000 shares of the Company’s common stock.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Aug. 31, 2013
Text Block [Abstract]	'
Accumulated Other Comprehensive Income (Loss)	'
	Note 9 — Accumulated Other Comprehensive Income (Loss)
	The components of accumulated other comprehensive loss and other comprehensive income (loss) are summarized below. The components of other comprehensive income (loss) and the income tax expense (benefit) allocated to each component of other comprehensive income (loss), including reclassification adjustments, are presented in the Consolidated Statements of Comprehensive Income (Loss).
	(In thousands)	Net Unrealized			Gains (Losses)			Accumulated
		Gains (Losses)			on			Other
		on Cash Flow			Postretirement			Comprehensive
		Hedging			Obligations			Loss
		Instruments
	Balance at August 31, 2010	$	(582	)	$	(13,268	)	$	(13,850	)
	Other comprehensive income (loss), net of taxes		1,313			4,978			6,291
	Balance at August 31, 2011		731			(8,290	)		(7,559	)
	Other comprehensive income (loss), net of taxes		907			(8,941	)		(8,034	)
	Balance at August 31, 2012		1,638			(17,231	)		(15,593	)
	Other comprehensive income (loss), net of taxes		(2,494	)		10,468			7,974
	Balance at August 31, 2013	$	(856	)	$	(6,763	)	$	(7,619	)

Leases

Leases	12 Months Ended
	Aug. 31, 2013
Leases [Abstract]	'
Leases	'
	Note 10 — Leases
	Certain of the Company’s property, plant and equipment is leased under operating leases. Equipment and vehicle leases generally have lease terms ranging from one to fifteen years with renewal options and real estate leases range between five and twenty years with renewal options. In fiscal 2013, 2012 and 2011, rental expense under operating leases was $6.3 million, $6.0 million and $5.4 million, respectively. Future minimum lease payments for fiscal years beginning with fiscal year 2014 for noncancelable operating leases and capital leases having initial lease terms of more than one year are as follows (dollars in thousands):
		Capital			Operating Leases
		Leases			Minimum Lease
					Payments
	2014	$	70		$	2,836
	2015		69			1,701
	2016		67			942
	2017		52			448
	2018		17			41
	Thereafter		9			-
	Total minimum lease payments		284		$	5,968
	Less: amounts representing interest		(53	)
	Net minimum lease payments	$	231

Stockbased_Compensation_Plans

Stock-based Compensation Plans	12 Months Ended
	Aug. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock-based Compensation Plans	'
	Note 11 — Stock-based Compensation Plans
	Penford maintains the 2006 Long-Term Incentive Plan (the “2006 Incentive Plan”) pursuant to which various stock-based awards may be granted to employees, directors and consultants. At the Annual Meeting of Shareholders of the Company held on January 26, 2012, the Company’s shareholders approved the amended Penford Corporation 2006 Long-Term Incentive Plan and the number of shares of the Company’s common stock available for issuance under the 2006 Incentive Plan was increased by 800,000 shares. As of August 31, 2013, the aggregate number of shares of the Company’s common stock that were available to be issued as awards under the 2006 Incentive Plan is 388,882. In addition, any shares previously granted under the 1994 Stock Option Plan which are subsequently forfeited or not exercised will be available for future grants under the 2006 Incentive Plan. Non-qualified stock options and restricted stock awards granted under the 2006 Incentive Plan generally vest ratably over one to four years and stock options expire seven years from the date of grant. In addition, the Company may from time to time award compensatory stock-based awards outside of the 2006 Incentive Plan to newly hired employees.
	General Option Information
	A summary of the stock option activity for the year ended August 31, 2013 is as follows:
		Number			Option Price			Weighted			Weighted		Aggregate
		of			Range			Average			Average		Intrinsic
		Shares						Exercise			Remaining		Value
								Price			Term (in
											years)
	Outstanding Balance, August 31, 2012		1,824,916		$	4.66 — 21.73		$	10.94
	Granted		120,000			7.60 — 11.09			8.49
	Exercised		(222,864	)		5.29 — 12.79			10.31
	Cancelled		(204,464	)		9.87 — 17.07			14.99
	Outstanding Balance, August 31, 2013		1,517,588			4.66 — 21.73			10.3			3.9	$	6,737,300
	Options Exercisable at August 31, 2013		895,339		$	4.66 — 21.73		$	13.17			2.74	$	2,144,000
	The aggregate intrinsic value disclosed in the table above represents the total pretax intrinsic value, based on the Company’s closing stock price of $13.55 per share as of August 31, 2013 that would have been received by the option holders had all option holders exercised on that date. The intrinsic value of options exercised during fiscal year 2013 was $835,300. No stock options were exercised in fiscal years 2012 and 2011.
	Valuation and Expense Under ASC 718
	The Company utilizes the Black-Scholes option-pricing model to determine the fair value of stock options on the date of grant. This model derives the fair value of stock options based on certain assumptions related to expected stock price volatility, expected option life, risk-free interest rate and dividend yield. The Company’s expected volatility is based on the historical volatility of the Company’s stock price over the most recent period commensurate with the expected term of the stock option award. The estimated expected option life is based primarily on historical employee exercise patterns and considers whether and the extent to which the options are in-the-money. The risk-free interest rate assumption is based upon the U.S. Treasury yield curve appropriate for the term of the Company’s stock options awards and the selected dividend yield assumption was determined in view of the Company’s historical and estimated dividend payout. The Company has no reason to believe that the expected volatility of its stock price or its option exercise patterns would differ significantly from historical volatility or option exercises.
	At the time of the acquisition of the business of Carolina Starches in fiscal 2012, the Company entered into compensatory stock option agreements outside of the Company’s 2006 Incentive Plan with the former owners of Carolina Starches. Pursuant to these agreements, the Company granted options to purchase an aggregate of 82,500 shares of the Company’s common stock at an exercise price equal to the closing price as of the close of business on January 11, 2012. These options have a term of seven years and, subject to certain conditions, vest ratably over a two year period.
	Under the 2006 Incentive Plan, the Company granted 120,000 stock options during fiscal 2013, 75,000 of which vest ratably over two years and 45,000 vest ratably over three years. The Company granted 678,000 stock options during fiscal 2012 which vest ratably over three years. In fiscal 2011, the Company granted 98,000 stock options, (i) 80,000 stock options which vest one year from the date of grant, and (ii) 18,000 stock options which vest ratably over four years. The Company estimated the fair value of stock options granted using the following weighted-average assumptions and resulting in the following weighted-average grant date fair value:
		2013		2012	2011
	Expected volatility	68%		68%	71%
	Expected life (years)	4.7		4.9	4.3
	Interest rate	0.5 -1.0%		0.5 -1.1%	1.1-2.8%
	Dividend yield	0%		0%	0%
	Weighted-average fair values	$4.60		$3.13	$3.62
	As of August 31, 2013, the Company had $0.9 million of unrecognized compensation costs related to non-vested stock option awards that are expected to be recognized over a weighted average period of 1.2 years.
	Restricted Stock Awards
	The grant date fair value of the Company’s restricted stock awards is equal to the fair value of Penford’s common stock at the grant date. The following table summarizes the restricted stock award activity for the twelve months ended August 31, 2013 as follows:
		Number of			Weighted
		Shares			Average
					Grant Date
					Fair Value
	Nonvested at August 31, 2012		61,716		$	5.94
	Granted		24,489			7.35
	Vested		(61,716	)		5.94
	Cancelled		-
	Nonvested at August 31, 2013		24,489		$	7.35
	The total grant date fair value of awards vested in 2013, 2012, and 2011 was $0.4 million, $1.0 million and $1.2 million, respectively. On January 1, 2013, each non-employee director received an award of 2,721 shares of restricted stock under the 2006 Incentive Plan at the last reported sale price of the stock on the preceding trading day, which vests one year from grant date of the award. On January 26, 2012, each non-employee director received an award of 3,539 shares of restricted stock under the 2006 Incentive Plan at the last reported sale price of the stock on the preceding trading day, which vested one year from grant date of the award. No restricted stock awards were granted in fiscal year 2011. The Company recognizes compensation cost for restricted stock ratably over the vesting period.
	As of August 31, 2013, the Company had less than $0.1 million of unrecognized compensation costs related to non-vested restricted stock awards that is expected to be recognized over a weighted average period of 0.3 years.
	Compensation Expense
	The Company recognizes stock-based compensation expense utilizing the accelerated multiple option approach over the requisite service period, which equals the vesting period. The following table summarizes the total stock-based compensation cost for fiscal years 2013, 2012 and 2011 and the effect on the Company’s consolidated statements of operations (dollars in thousands):
		2013			2012			2011
	Cost of sales	$	-		$	48		$	130
	Operating expenses		1,404			1,324			949
	Research and development expenses		-			15			38
	Total stock-based compensation expense	$	1,404		$	1,387		$	1,117
	Income tax benefit		(534	)		(527	)		(424	)
	Total stock-based compensation expense, net of tax	$	870		$	860		$	693

Pensions_and_Other_Postretirem

Pensions and Other Postretirement Benefits	12 Months Ended
	Aug. 31, 2013
Compensation And Retirement Disclosure [Abstract]	'
Pensions and Other Postretirement Benefits	'
	Note 12 — Pensions and Other Postretirement Benefits
	Penford maintains two noncontributory defined benefit pension plans that cover approximately 56% of its employees. The defined benefit pension plans for salaried and bargaining unit hourly employees were closed to new participants effective January 1, 2005 and August 1, 2004, respectively. The Company also maintains a postretirement health care benefit plan covering its bargaining unit hourly retirees. Effective August 1, 2004, the Company’s postretirement health care benefit plan covering bargaining unit hourly employees was closed to new entrants and to any current employee who did not meet minimum requirements as to age plus years of service. For the plans described above, the Company determines the vested benefit obligation on the actuarial present value based on the employee’s expected date of retirement.
	Obligations and Funded Status
	The following represents information summarizing the Company’s pension and other postretirement benefit plans. A measurement date of August 31, 2013 was used for all plans.
		Year Ended August 31,
		Pension Benefits						Other Benefits
		2013			2012			2013			2012
		(Dollars in thousands)
	Change in benefit obligation:
	Benefit obligation at September 1	$	62,989		$	47,545		$	20,457		$	16,924
	Service cost		1,945			1,521			235			229
	Interest cost		2,648			2,729			860			972
	Plan participants’ contributions		—			—			106			119
	Amendments		—			212			—			—
	Actuarial (gain) loss		(107	)		619			267			(170	)
	Change in assumptions		(8,135	)		12,359			(3,912	)		3,024
	Benefits paid		(2,062	)		(1,996	)		(657	)		(641	)
	Benefit obligation at August 31	$	57,278		$	62,989		$	17,356		$	20,457
	Change in plan assets:
	Fair value of plan assets at September 1	$	42,072		$	36,328		$	—		$	—
	Actual return on plan assets		5,580			3,688			—			—
	Company contributions		1,136			4,052			551			522
	Plan participants’ contributions		—			—			106			119
	Benefits paid		(2,062	)		(1,996	)		(657	)		(641	)
	Fair value of the plan assets at August 31	$	46,726		$	42,072		$	—		$	—
	Funded status:
	Net liability – Plan assets less than projected benefit obligation	$	(10,552	)	$	(20,917	)	$	(17,356	)	$	(20,457	)
	Recognized as:
	Current accrued benefit liability	$	—		$	—		$	(760	)	$	(750	)
	Non-current accrued benefit liability		(10,552	)		(20,917	)		(16,596	)		(19,707	)
	Net Amount Recognized	$	(10,552	)	$	(20,917	)	$	(17,356	)	$	(20,457	)
	Accumulated other comprehensive loss consists of the following amounts that have not yet been recognized as components of net benefit cost (dollars in thousands):
		August 31, 2013						August 31, 2012
		Pension			Other			Pension			Other
		Benefits			Benefits			Benefits			Benefits
	Unrecognized prior service cost (credit)	$	1,288		$	(155	)	$	1,529		$	(307	)
	Unrecognized net actuarial loss		10,091			(318	)		22,976			3,594
	Total	$	11,379		$	(473	)	$	24,505		$	3,287
	Selected information related to the Company’s defined benefit pension plans that have benefit obligations in excess of fair value of plan assets is presented below (dollars in thousands):
		August 31,
		2013			2012
	Projected benefit obligation	$	57,278		$	62,989
	Accumulated benefit obligation	$	54,389		$	59,853
	Fair value of plan assets	$	46,726		$	42,072
	Net Periodic Benefit Cost
		Year Ended August 31,
		Pension Benefits									Other Benefits
		2013			2012			2011			2013			2012			2011
		(Dollars in thousands)
	Components of net periodic benefit cost
	Service cost	$	1,945		$	1,521		$	1,617		$	235		$	229		$	272
	Interest cost		2,648			2,729			2,696			860			972			972
	Expected return on plan assets		(2,869	)		(2,914	)		(2,234	)		—			—			—
	Amortization of prior service cost		241			228			228			(152	)		(152	)		(152	)
	Amortization of actuarial loss		1,932			773			1,441			267			—			65
	Benefit cost	$	3,897		$	2,337		$	3,748		$	1,210		$	1,049		$	1,157
	Assumptions
	The Company assesses its benefit plan assumptions on a regular basis. Assumptions used in determining plan information are as follows:
		August 31,
		Pension Benefits									Other Benefits
		2013			2012			2011			2013			2012			2011
	Weighted-average assumptions used to calculate net periodic expense:
	Discount rate		4.28	%		5.87	%		5.64	%		4.28	%		5.87	%		5.64	%
Expected return on plan assets		7	%		8	%		8	%
Rate of compensation increase		3	%		3	%		4	%
Weighted-average assumptions used to calculate benefit obligations at August 31:
Discount rate		5.24	%		4.28	%		5.87	%		5.24	%		4.28	%		5.87	%
Expected return on plan assets		7	%		7	%		8	%
Rate of compensation increase		3	%		3	%		3	%
The expected long-term return on assets assumption for the pension plans represents the average rate of return to be earned on plan assets over the period the benefits included in the benefit obligation are to be paid. In developing the expected rate of return, the Company considers long-term historical market rates of return as well as actual returns on the Company’s plan assets, and adjusts this information to reflect expected capital market trends. Penford also considers forward looking return expectations by asset class, the contribution of active management and management fees paid by the plans. The plan assets are held in qualified trusts and anticipated rates of return are not reduced for income taxes. The expected long-term return on assets assumption used to calculate net periodic pension expense was 7.0% for fiscal 2013. A decrease (increase) of 50 basis points in the expected return on assets assumptions would increase (decrease) pension expense by approximately $0.2 million based on the assets of the plans at August 31, 2013. The expected return on plan assets to be used in calculating fiscal 2014 pension expense is 7.0%.
The discount rate used by the Company in determining pension expense and pension obligations reflects the yield of high quality (AA or better rating by a recognized rating agency) corporate bonds whose cash flows are expected to match the timing and amounts of projected future benefit payments. The discount rates to determine net periodic expense used in fiscal 2011 (5.64%), fiscal 2012 (5.87%) and fiscal 2013 (4.28%) reflect the change in bond yields over the last several years. During fiscal 2013, bond yields increased and Penford has increased the discount rate for calculating its benefit obligations at August 31, 2013, as well as net periodic expense for fiscal 2014, to 5.24%. Lowering the discount rate by 25 basis points would increase pension expense by approximately $0.24 million. The effect of lowering the discount rate by 25 basis points on other postretirement benefit expense would not be material.
Unrecognized net loss amounts reflect the difference between expected and actual returns on pension plan assets as well as the effects of changes in actuarial assumptions. Unrecognized net losses in excess of certain thresholds are amortized into net periodic pension and postretirement benefit expense over the average remaining service life of active employees. Amortization of unrecognized net loss amounts is expected to increase net pension expense by approximately $0.5 million in fiscal 2014. Amortization of unrecognized net losses is not expected to increase net postretirement health care expense in fiscal 2014.
Assumed health care cost trend rates:		2013			2012			2011
Current health care trend assumption		7.8	%		8	%		8	%
Ultimate health care trend rate		4.5	%		4.5	%		4.5	%
Year ultimate health care trend is reached		2032			2030			2029
The assumed health care cost trend rate could have a significant effect on the amounts reported. A one-percentage-point change in the assumed health care cost trend rate would have the following effects:
	1-Percentage-			1-Percentage-
	Point			Point
	Increase			Decrease
	(Dollars in thousands)
Effect on total of service and interest cost components in fiscal 2013	$	182		$	(146	)
Effect on postretirement accumulated benefit obligation as of August 31, 2013	$	2,405		$	(1,999	)
Plan Assets
The weighted average asset allocations of the investment portfolio for the pension plans at August 31 are as follows:
	Target			August 31,
	Allocation			2013			2012
U.S. equities		55	%		55	%		56	%
International equities		15	%		15	%		15	%
Fixed income investments		25	%		25	%		24	%
Real estate		5	%		5	%		5	%
During fiscal 2013, the assets of the pension plans are invested in units of common trust funds actively managed by Russell Trust Company, a professional fund investment manager. The investment strategy for the defined benefit pension assets is to maintain a diversified asset allocation in order to minimize the risk of large losses and maximize the long-term risk-adjusted rate of return. No plan assets are invested in Penford shares. There are no plan assets for the Company’s postretirement health care plans.
See Note 14, “Fair Value Measurements and Derivative Instruments,” for a description of the fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The Company’s employee pension plan assets are principally comprised of the following types of investments:
Common collective trust funds:  The fair value of these funds is based on the cumulative net asset value of their underlying investments. The investments in common collective trust funds are comprised of equity funds, fixed income funds and international equity funds. The funds are valued at net asset value based on the closing market value of the units bought or sold as of the valuation date and are classified in Level 2 of the fair value hierarchy.
Real estate equity funds:  The real estate equity funds are composed of underlying investments in primarily nine established income-producing real estate funds and short-term investment funds. The underlying fund net asset values are based on the values of the real estate assets as determined by appraisal. The appraisals are conducted in accordance with Appraisal Institute guidelines including consideration of projected income and expenses of the property as well as recent sales of similar properties. The underlying funds value all real estate investments quarterly and all real estate investments are independently appraised at least once per year as required by the Global Investment Performance Standards. Redemption requests are considered quarterly and are subject to notice of 110 days. The real estate fund is included in Level 3 of the fair value hierarchy.
The following table presents the fair value of the pension plan’s assets by major asset category as of August 31, 2013.
	Quoted Prices			Significant			Significant			Total
	In Active			Other			Unobservable
	Markets for			Observable			Inputs
	Identical			Inputs			(Level 3)
	Instruments			(Level 2)
	(Level 1)
	(in thousands)
Common collective trust funds	$			$	44,378		$	-		$	44,378
Real estate equity funds		-			-			2,348			2,348
Fair value of plan assets	$	-		$	44,378		$	2,348		$	46,726
The following table summarizes the changes in fair value of the pension plan’s real estate equity fund (Level 3) for fiscal year ended August 31, 2013.
	Real Estate
	Equity Fund
	(in thousands)
Balance, August 31, 2012	$	2,102
Actual return on plan assets:
Relating to assets still held at the reporting date		246
Relating to assets sold during the period		-
Purchases and sales		-
Transfers in (out) of Level 3		-
Balance, August 31, 2013	$	2,348
Contributions and Benefit Payments
The Company’s funding policy for the defined benefit pension plans is to contribute amounts sufficient to meet the statutory funding requirements of the Employee Retirement Income Security Act of 1974 and the Pension Protection Act of 2006. The Company contributed $1.1 million, $4.1 million and $6.4 million in fiscal 2013, 2012 and 2011, respectively. The Company estimates that the minimum pension plan funding contribution during fiscal 2014 will be approximately $2.5 million.
Penford funds the benefit payments of its postretirement health care plans on a cash basis; therefore, the Company’s contributions to these plans in fiscal 2014 will approximate the benefit payments below.
Expected benefit payments are based on the same assumptions used to measure the benefit obligations and include benefits attributable to estimate future employee service.
	Pension			Other
				Postretirement
	(Dollars in millions)
2014	$	2.4		$	0.9
2015		2.5			1
2016		2.6			1
2017		2.8			1.1
2018		3			1.2
2019-2023	$	18.7		$	7.7

Other_Employee_Benefits

Other Employee Benefits	12 Months Ended
	Aug. 31, 2013
Postemployment Benefits [Abstract]	'
Other Employee Benefits	'
	Note 13 — Other Employee Benefits
	Savings and Stock Ownership Plan
	The Company has a defined contribution savings plan by which eligible employees can elect a maximum salary deferral of 16%. The plan provides a 100% match on the first 3% of salary contributions and a 50% match on the next 3% per employee. The Company’s matching contributions were $1.2 million, $1.0 million and $0.9 million for fiscal years 2013, 2012 and 2011, respectively.
	Deferred Compensation Plan
	The Company provided its directors and certain employees the opportunity to defer a portion of their salary, bonus and fees. The plan was closed to new contributions effective January 31, 2011. The deferrals earn interest based on Moody’s current Corporate Bond Yield. Deferred compensation interest of $177,000, $179,000 and $197,000 was accrued in fiscal years 2013, 2012 and 2011, respectively.
	Supplemental Executive Retirement Plan
	The Company sponsors a supplemental executive retirement plan, a non-qualified plan, which covers certain employees. No current executive officers participate in this plan. For fiscal 2013, 2012 and 2011, the net periodic pension expense accrued for this plan was $271,000, $258,000 and $370,000, respectively. The accrued obligation related to the plan was $2.7 million at August 31, 2013 and 2012. The plan was amended in fiscal 2011 such that no participant in the plan would accrue any additional benefits after January 31, 2011.
	Health Care and Life Insurance Benefits
	The Company offers health care and life insurance benefits to most active employees. Costs incurred to provide these benefits are charged to expense as incurred. Health care and life insurance expense, net of employee contributions, was $5.9 million, $5.1 million and $4.5 million in fiscal years 2013, 2012 and 2011, respectively.

Fair_Value_Measurements_and_De

Fair Value Measurements and Derivative Instruments	12 Months Ended
	Aug. 31, 2013
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'
Fair Value Measurements and Derivative Instruments	'
	Note 14 — Fair Value Measurements and Derivative Instruments
	Fair Value Measurements
	Fair value is defined as the price that would be received from selling an asset or paid to transfer a liability (an exit price) in Penford’s principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. A fair value hierarchy was established that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Observable inputs are inputs that reflect the assumptions market participants would use in pricing the asset or liability developed based on market data obtained from sources outside the reporting entity. Unobservable inputs are inputs that reflect Penford’s own assumptions based on market data and on assumptions that market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. The three levels of inputs that may be used to measure fair value are:
		•		Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the entity has the ability to access at the measurement date.
		•		Level 2 inputs are other than quoted prices included within Level 1 that are observable for assets and liabilities such as (1) quoted prices for similar assets or liabilities in active markets, (2) quoted prices for identical or similar assets or liabilities in markets that are not active, or (3) inputs that are derived principally or corroborated by observable market date by correlation or other means.
		•		Level 3 inputs are unobservable inputs to the valuation methodology for the assets or liabilities.
	Presented below are the fair values of the Company’s derivative instruments as of August 31, 2013 and 2012:
	As of August 31, 2013		(Level 1)				(Level 2)				(Level 3)			Total
			(in thousands)
	Current assets (Other Current Assets):
	Commodity derivatives (1)		$	512			$	-			$	-		$	512
	(1) On the consolidated balance sheets, commodity derivative assets and liabilities have been offset by cash collateral due and paid under master netting arrangements which are recorded together in Other Current Assets. The cash collateral offset was $1.7 million at August 31, 2013.
	As of August 31, 2012		(Level 1)				(Level 2)				(Level 3)			Total
			(in thousands)
	Current assets (Other Current Assets):
	Commodity derivatives (1)		$	(1,422)			$	-			$	-		$	(1,422)
	(1) On the consolidated balance sheets, commodity derivative assets and liabilities have been offset by cash collateral due and paid under master netting arrangements which are recorded together in Other Current Assets. The cash collateral offset was $2.6 million at August 31, 2012.
	Other Financial Instruments
	The carrying value of cash and cash equivalents, receivables and payables approximates fair value because of their short maturities. The Company’s bank debt interest rate reprices with changes in market interest rates and, accordingly, the carrying amount of such debt approximates fair value.
	In fiscal 2010, the Company received two non-interest bearing loans from the State of Iowa. The carrying value of the debt at August 31, 2013 was $1.2 million and the fair value of the debt was estimated to be $1.2 million. See Note 7. The fair value was computed using a discounted cash flow methodology. The discount rate was selected by reference to corporate debenture yields for comparable companies. The fair value was computed using Level 2 inputs.
	Commodity Contracts
	For derivative instruments designated as fair value hedges, the gain or loss on the derivative instruments as well as the offsetting gain or loss on the hedged firm commitments and/or inventory are recognized in current earnings as a component of cost of sales. For derivative instruments designated as cash flow hedges, the effective portion of the gain or loss on the derivative instruments is reported as a component of other comprehensive income (loss), net of applicable income taxes, and recognized in earnings when the hedged exposure affects earnings. The Company recognizes the gain or loss on the derivative instrument as a component of cost of sales in the period when the finished goods produced from the hedged item are sold. If it is determined that the derivative instruments used are no longer effective at offsetting changes in the price of the hedged item, then the changes in fair value would be recognized in current earnings as a component of cost of goods sold.
	To reduce the price volatility of corn used in fulfilling some of its starch sales contracts, Penford uses readily marketable exchange-traded futures as well as forward cash corn purchases. Penford also uses exchange-traded futures to hedge corn inventories, firm commitments to purchase corn and forecasted purchases of corn. The exchange-traded futures are not purchased or sold for trading or speculative purposes and are designated as hedges. These futures contracts were designated as hedges.
	Prices for natural gas fluctuate due to anticipated changes in supply and demand and movement of prices of related or alternative fuels. To reduce the price risk caused by market fluctuations, Penford generally enters into short-term purchase contracts or uses exchange-traded futures contracts to hedge exposure to natural gas price fluctuations. These futures contracts were designated as hedges prior to fiscal 2012. In September 2011, the Company discontinued hedge accounting treatment for natural gas futures contracts as the hedging relationship no longer met the requirements for hedge accounting. Through August 31, 2011, the gains and losses on natural gas futures contracts were deferred in accumulated other comprehensive income. At the time hedge accounting was discontinued, $0.5 million of pretax losses continued to be deferred in accumulated other comprehensive income for these natural gas futures contracts. These losses were reclassified to cost of sales during fiscal 2012 as the originally forecasted cash flows occurred. Gains and losses on natural gas futures contracts since August 31, 2011 were recognized in cost of sales in the Consolidated Statement of Operations.
	Selling prices for ethanol fluctuate based on the availability and price of manufacturing inputs and the status of various government regulations and tax incentives. To reduce the risk of the price variability of ethanol, Penford enters into exchange-traded futures contracts to hedge exposure to ethanol price fluctuations. These futures contracts have been designated as hedges.
	Hedged transactions are generally expected to occur within 12 months of the time the hedge is established. The deferred gain (loss), net of tax, recorded in other comprehensive income at August 31, 2013 that is expected to be reclassified into income within 12 months is $(0.9) million.
	As of August 31, 2013, Penford had purchased corn positions of 3.1 million bushels, of which 2.2 million bushels represented equivalent firm priced starch and ethanol sales contract volume, resulting in an open position of 0.9 million bushels.
	As of August 31, 2013, the Company had the following outstanding futures contracts:
	Corn Futures			4,190,000				Bushels
	Ethanol Swaps			7,350,000				Gallons
	The following tables provide information about the fair values of the Company’s derivatives, by contract type, as of August 31, 2013 and 2012.
			Assets										Liabilities
	In thousands				Fair Value August 31									Fair Value August 31
			Balance Sheet		2013				2012				Balance Sheet	2013			2012
			Location										Location
	Derivatives designated as hedging instruments:
	Cash Flow Hedges:
	Corn Futures		Other Current Assets		$	-			$	12			Other Current Assets	$	485		$	126
	Ethanol Futures		Other Current Assets			997				-			Other Current Assets		-			706
	Fair Value Hedges:
	Corn Futures		Other Current Assets			-				-			Other Current Assets		-			602
					$	997			$	12				$	485		$	1,434
	The following tables provide information about the effect of derivative instruments on the financial performance of the Company for the fiscal years ended August 31, 2013, 2012 and 2011.
	In thousands		Amount of Gain (Loss)											Amount of Gain (Loss)									Amount of Gain (Loss)
			Recognized in AOCI											Reclassified from									Recognized in Income
														AOCI into Income
			Year Ended August 31											Year Ended August 31									Year Ended August 31
			2013				2012				2011			2013			2012			2011			2013			2012			2011
	Derivatives designated as hedging instruments:
	Cash Flow Hedges:
	Corn Futures (1)		$	(407	)		$	2,067			$	(4,949	)	$	5,351		$	1,500		$	(7,418	)	$	(870	)	$	36		$	(162	)
	Natural Gas Futures (1)			-				-				(579	)		-			(492	)		(1,332	)		-			-			(85	)
	Ethanol Futures (1)			1,611				1,667				(4,180	)		(123	)		1,263			(3,075	)		(151	)		-			-
			$	1,204			$	3,734			$	(9,708	)	$	5,228		$	2,271		$	(11,825	)	$	(1,021	)	$	36		$	(247	)
	Fair Value Hedges:
	Corn Futures (1) (2)																						$	363		$	98			28
	Derivatives not designated as hedging instruments:
	Natural Gas Futures (1)																						$	94		$	(1,082	)	$	-
	FX Contracts (1)																							-			6			-
	Soybean Oil Futures (1)																							-			12			-
	Soybean Meal Futures (1)																							-			(14	)		-
																							$	94		$	(1,078	)	$	-
	(1) Gains and losses reported in cost of goods sold
(2) Hedged items are firm commitments and inventory

Other_Nonoperating_Income_Expe

Other Non-operating Income (Expense)	12 Months Ended
	Aug. 31, 2013
Other Income And Expenses [Abstract]	'
Other Non-operating Income (Expense)	'
	Note 15 — Other Non-operating Income (Expense)
	Other non-operating income (expense) consists of the following:
		Year Ended August 31,
		2013		2012			2011
		(Dollars in thousands)
	Loss on redemption of Series A Preferred Stock	$	—	$	(6,599	)	$	—
	Other		75		413			115
		$	75	$	(6,186	)	$	115
	In 2012 the Company redeemed its Series A Preferred Stock. See Note 6. In fiscal 2012, the Company redeemed 100,000 shares at the original issue price of $40.0 million plus accrued dividends of $8.9 million. As a result of the early redemptions, the Company recorded accelerated discount accretion of $5.5 million and amortization of issuance costs of $1.1 million as a loss on redemption in other non-operating income (expense).

Income_Taxes

Income Taxes	12 Months Ended
	Aug. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Note 16 — Income Taxes
	The Company’s U.S. income (loss) before income taxes for fiscal years 2013, 2012 and 2011 was $5.0 million, $(4.9) million, and $(4.2) million, respectively. Foreign income (loss) before income taxes for fiscal years 2013, 2012, and 2011 was $0.5 million, $0.1 million, and (0.6) million, respectively. Foreign tax expense for all three years was zero.
	U.S. Income tax expense (benefit) consists of the following:
		Year Ended August 31,
		2013			2012			2011
		(Dollars in thousands)
	Current:
	Federal	$	(422	)	$	(162	)	$	34
	State		80			3			137
			(342	)		(159	)		171
	Deferred:
	Federal		1,829			4,582			9
	State		(4	)		383			133
			1,825			4,965			142
	Total		$1,483			$4,806			$313
		Year Ended August 31,
		2013			2012			2011
		(Dollars in thousands)
	Comprehensive tax expense (benefit) allocable to:
	Income before taxes	$	1,483		$	4,806		$	313
	Comprehensive income (loss)		4,887			(4,924	)		3,856
		$	6,370		$	(118	)	$	4,169
	A reconciliation of the statutory federal tax to the actual provision (benefit) for taxes is as follows:
		Year Ended August 31,
		2013			2012			2011
		(Dollars in thousands)
	Statutory tax rate		35%			35%			35%
	Statutory tax on income	$	1,921		$	(1,666	)	$	(1,682	)
	State taxes, net of federal benefit		94			219			52
	Non-deductible expenses related to preferred stock		-			4,547			2,687
	Research credit		(189	)		(73	)		(195	)
	Ethanol credit		-			-			(975	)
	Foreign taxes		(183	)		(38	)		200
	Stock option exercises/expirations		376			-			-
	Prior year true up		(265	)		95			79
	Unrecognized tax benefits		(359	)		(165	)		67
	Valuation allowance		(104	)		1,787			-
	Other		192			100			80
	Total provision (benefit)	$	1,483		$	4,806		$	313
	The significant components of deferred tax assets and liabilities are as follows:
		August 31,
		2013			2012
		(Dollars in thousands)
	Deferred tax assets:
	Alternative minimum tax credit	$	3,473		$	3,354
	Postretirement benefits		11,920			18,060
	Provisions for accrued expenses		2,791			2,908
	Stock-based compensation		2,453			2,420
	Net operating loss carryforward		4,575			7,469
	Tax credit carryforwards		4,373			4,152
	NOL carryforward-foreign		10,853			11,010
	Hedging		525			-
	Other		2,092			2,025
			43,055			51,398
	Less - valuation allowance		(12,537	)		(12,797	)
	Total deferred tax assets		30,518			38,601
	Deferred tax liabilities:
	Depreciation		22,296			21,762
	Hedging		-			1,004
	Other		1,756			2,560
	Total deferred tax liabilities		24,052			25,326
	Net deferred tax assets	$	6,466		$	13,275
	Recognized as:
Other current assets	$	1,479		$	167
Deferred tax asset		4,987			13,108
Total net deferred tax assets	$	6,466		$	13,275
Carryforwards
At August 31, 2013, the Company had a U.S. federal alternative minimum tax credit carryforward of $3.5 million with no expiration, research and development credit carryforwards of $1.7 million expiring 2025 through 2032, a small ethanol producer credit of $2.6 million expiring 2014, and a net operating loss carryforward of $10.8 million expiring in 2030. The Company also has U.S. state net operating loss carryforwards of $19.8 million with expiration dates between 2014 and 2030.
Valuation Allowance
In fiscal 2012, the Company recorded a $1.8 million valuation allowance related to small ethanol producer tax credit carryforwards which expire in fiscal 2014. Tax laws require that any net operating loss carryforwards be utilized before the Company can utilize the small ethanol producer tax credit carryforwards. As a result of challenging market trends related to the cost of corn and ethanol pricing and the redemptions of the Company’s Series A Preferred Stock discussed in Note 6, estimates of future taxable income during the carryforward periods were revised. Due to the near-term expiration of the small ethanol producer tax credit carryforward period, the Company did not believe it had sufficient positive evidence to substantiate that the small ethanol tax credit carryforwards were realizable at a more-likely-than-not level of assurance and recorded a $1.8 million valuation allowance. During fiscal 2013, $0.1 million of the valuation allowance was reversed as the Company expects to utilize the credit. The remaining valuation allowance will be reversed in future periods if it is more likely than not that these tax credit carryforwards will be utilized.
In fiscal 2012, the Company recorded a $44,000 valuation allowance related to charitable contributions which expire in fiscal years 2013 through 2015. In fiscal 2013, the valuation allowance was reduced by $22,000 as a portion of the charitable contributions carryforward expired unused. Tax laws limit the deduction of charitable contributions to 10% of otherwise taxable income with the excess carried forward for five years. Utilization of net operating loss carryforwards are considered to reduce taxable income. Due to the near-term expiration of these deductions, the Company did not believe that it had sufficient positive evidence to substantiate that the charitable contributions carryforwards were realizable at a more-likely-than-not level of assurance and recorded a valuation allowance. The valuation allowance will be reversed in future periods if it is more likely than not that these deductions will be utilized.
At August 31, 2013, the Company had $6.5 million of U.S. net deferred tax assets. Other than for the ethanol tax credit and charitable contributions discussed above, a valuation allowance has not been provided on the net U.S. deferred tax assets as of August 31, 2013. The determination of the need for a valuation allowance requires significant judgment and estimates. The Company evaluates the requirement for a valuation allowance each quarter as the Company incurred book losses in fiscal 2012 and the two previous fiscal years. The Company believes that it is more likely than not that future operations will generate sufficient taxable income to realize its deferred tax assets. However, there can be no assurance that management’s current plans will be achieved or that a valuation allowance will not be required in the future.
The Company sold the assets of its Australia/New Zealand operations in fiscal 2010. The Company believes that it is more likely than not that the net deferred tax asset of $10.9 million recorded for the Australian operations will not be realized. The Company’s discontinued Australian operations recorded a valuation allowance as of August 31, 2013 of $10.9 million against the entire Australian net deferred tax asset.
Uncertain Tax Positions
The total amount of gross unrecognized tax benefits was $0.7 million at August 31, 2013, all of which, if recognized, would impact the Company’s effective tax rate. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (dollars in thousands):
	2013			2012
Unrecognized tax benefits at beginning of year	$	1,058		$	1,220
Additions for tax positions related to prior years		134			112
Additions for tax positions related to current year		90			62
Reductions due to lapse of applicable statute of limitations		(576	)		(336	)
Unrecognized tax benefits at end of year	$	706		$	1,058
The Company’s policy is to recognize interest and penalty expense associated with uncertain tax positions as a component of income tax expense (benefit) in the consolidated statements of operations. As of August 31, 2013 and 2012, the Company had $0.1 million and $0.2 million, respectively, of accrued interest and penalties included in the long-term tax liability. During fiscal 2013, the Company decreased the liability for unrecognized tax benefits by $44,000 for interest and $51,000 for penalties.
Other
The Company files tax returns in the U.S. federal jurisdiction and various U.S. state jurisdictions, and is subject to examination by taxing authorities in all of those jurisdictions. From time to time, the Company’s tax returns are reviewed or audited by U.S. federal and various U.S. state taxing authorities. The Company believes that adjustments, if any, resulting from these reviews or audits would not be material, individually or in the aggregate, to the Company’s financial position, results of operations or liquidity. It is reasonably possible that the amount of unrecognized tax benefits related to certain of the Company’s tax positions will increase or decrease in the next twelve months as audits or reviews are initiated and settled. At this time, an estimate of the range of a reasonably possible change cannot be made. The Company is not subject to income tax examinations by U.S. federal or state jurisdictions for fiscal years prior to 2009.
Deferred tax liabilities or assets are not recognized on temporary differences from undistributed earnings of foreign subsidiaries and from foreign exchange translation gains or losses on permanent advances to foreign subsidiaries as the Company does not expect that the divestiture of its foreign subsidiaries will result in any tax benefit or expense.

Earnings_loss_per_Common_Share

Earnings (loss) per Common Share	12 Months Ended
	Aug. 31, 2013
Earnings Per Share [Abstract]	'
Earnings (loss) per Common Share	'
	Note 17 — Earnings (loss) per Common Share
	Outstanding unvested share-based payment awards that contain rights to non-forfeitable dividends participate in undistributed earnings with common shareholders and, therefore, are included in computing earnings per share under the two-class method. Under the two-class method, net earnings are reduced by the amount of dividends declared in the period for each class of common stock and participating security. The remaining undistributed earnings are then allocated to common stock and participating securities, based on their respective rights to receive dividends. Restricted stock awards granted to certain employees and directors under the Company’s 2006 Incentive Plan, which contain non-forfeitable rights to dividends at the same rate as common stock, are considered participating securities.
	Basic earnings (loss) per share reflect only the weighted average common shares outstanding during the period. Diluted earnings (loss) per share reflect weighted average common shares outstanding and the effect of any dilutive common stock equivalent shares. Diluted earnings (loss) per share is calculated by dividing net income (loss) by the average common shares outstanding plus additional common shares that would have been outstanding assuming the exercise of in-the-money stock options, using the treasury stock method. The following table presents the reconciliation of net income (loss) to net income (loss) applicable to common shares and the computation of diluted weighted average shares outstanding for the fiscal years 2013, 2012 and 2011.
		Year Ended August 31,
		2013			2012			2011
		(in thousands)
	Numerator:
	Net income (loss)	$	4,007		$	(9,566	)	$	(5,117	)
	Less: Allocation to participating securities		(11	)		-			-
	Net income (loss) applicable to common shares and equivalents	$	3,996		$	(9,566	)	$	(5,117	)
	Denominator:
	Weighted average common shares and equivalents outstanding, basic		12,369			12,294			12,251
	Dilutive stock options and awards		249			-			-
	Weighted average common shares and equivalents outstanding, diluted		12,618			12,294			12,251
	The 100,000 shares of Series B Preferred Stock are included in the fiscal 2011 weighted average common shares and equivalents computation of basic earnings per share. During the third quarter of fiscal 2012, the Investor converted its 100,000 shares of Series B Preferred Stock into 1,000,000 shares of the Company’s common stock. See Note 6.
	Weighted-average restricted stock awards of 57,443 and 98,158 for fiscal years 2012 and 2011, respectively, were excluded from the calculation of diluted earnings per share because they were antidilutive. Weighted-average stock options omitted from the denominator of the earnings per share calculation because they were antidilutive were 896,354, 1,648,704 and 1,325,945 for fiscal years 2013, 2012 and 2011, respectively.

Carolina_Starches_Acquisition

Carolina Starches Acquisition	12 Months Ended
	Aug. 31, 2013
Business Combinations [Abstract]	'
Carolina Starches Acquisition	'
	Note 18 — Carolina Starches Acquisition
	On January 11, 2012, Penford Carolina, LLC, a Delaware limited liability company (“Purchaser”) and a wholly-owned subsidiary of the Company, entered into an Amended and Restated Business Sale and Membership Interest Purchase Agreement (the “Amended and Restated Purchase Agreement”) providing for the purchase of Carolina Starches for $8.5 million in cash. Penford Carolina, LLC manufactures, markets and sells industrial cationic starches produced from potato, corn and tapioca into the paper and packaging industry. The acquisition of these businesses provides an important source of raw material to support continued growth in the Food Ingredients business and broadens the Company’s portfolio of specialty modified industrial starches.
	The acquisition of Carolina Starches was accounted for as a business combination under the acquisition method. The final allocation of the purchase price to the assets acquired and liabilities assumed, based on their fair values as of January 11, 2012, is presented below. Goodwill represents the amount by which the purchase price exceeded the fair value of the net assets acquired and has been allocated to the Food Ingredients segment. It is estimated that all of the goodwill associated with this acquisition is deductible for tax purposes. Pro forma results of operations have not been included as the results were not significant to the historical periods.
	(in thousands)
	Property, plant and equipment	$	3,947
	Working capital		4,225
	Other assets		141
	Intangible assets		290
	Goodwill		81
	Non-current liabilities		(184	)
	Total purchase price	$	8,500

Segment_Reporting

Segment Reporting	12 Months Ended
	Aug. 31, 2013
Segment Reporting [Abstract]	'
Segment Reporting	'
	Note 19 — Segment Reporting
	Financial information for the Company’s two segments, Industrial Ingredients and Food Ingredients, is presented below. Industrial Ingredients and Food Ingredients are broad categories of end-market users served by the Company’s U.S. operations. Penford manages its business in two segments: Industrial Ingredients and Food Ingredients. These segments are based on broad categories of end-market users. The Food Ingredients segment produces specialty starches for food applications. The Industrial Ingredients segment is a supplier of specialty starches to the paper, packaging and other industries, and is a producer of fuel grade ethanol. The Industrial Ingredients segment also sells the by-products from its corn wet milling manufacturing operations, primarily germ, fiber and gluten to customers who use these by-products as animal feed or to produce corn oil.
	A third item for “corporate and other” activity has been presented to provide reconciliation to amounts reported in the consolidated financial statements. Corporate and other represents the activities related to the corporate headquarters such as public company reporting, personnel costs of the executive management team, corporate-wide professional services and consolidation entries. The accounting policies of the reportable segments are the same as those described in Note 2. The Company’s assets and manufacturing operations are located in the United States.
		Year Ended August 31,
		2013			2012			2011
		(Dollars in thousands)
	Sales
	Industrial ingredients
	Industrial Starch	$	177,382		$	156,945		$	127,471
	Ethanol		96,852			101,874			105,730
	By-products		81,782			71,788			58,322
		$	356,016		$	330,607		$	291,523
	Food ingredients		111,234			102,544			82,240
		$	467,250		$	433,151		$	373,763
	Depreciation and amortization
	Industrial ingredients	$	10,933		$	10,879		$	10,812
	Food ingredients		2,061			1,989			2,110
	Corporate and other		332			1,259			1,493
		$	13,326		$	14,127		$	14,415
	Income (loss) from operations
	Industrial ingredients	$	(3,238	)	$	(928	)	$	(4,718	)
	Food ingredients		23,265			21,591			18,037
	Corporate and other		(10,623	)		(10,604	)		(8,874	)
		$	9,404		$	10,059		$	4,445
	Capital expenditures, net
	Industrial ingredients	$	8,997		$	8,700		$	6,625
	Food ingredients		5,202			5,446			1,663
	Corporate and other		-			-			7
		$	14,199		$	14,146		$	8,295
		August 31,
		2013			2012
		(Dollars in thousands)
	Total assets
	Industrial ingredients	$	133,120		$	143,039
	Food ingredients		68,550			63,949
	Corporate and other		22,948			29,191
		$	224,618		$	236,179
	In January 2012, the Company acquired the net assets and operations of the business generally known as Carolina Starches, which manufactures and markets industrial potato starch based products and blends for the paper and packaging industries. See Note 18. The net assets and results of operations since acquisition have been integrated into the Company’s existing business segments. The acquired net assets, consisting primarily of property, plant and equipment and working capital, are being managed by and included in the reported balance sheet amounts of the Company’s Food Ingredients business, which has experience, expertise and technologies related to the manufacture of potato starch products.
	Since the primary end markets for Carolina Starches’ products are the paper and packaging industries, the Carolina Starches sales and marketing functions of the acquired operations are being managed by the Industrial Ingredients business; therefore, the sales, cost of sales and a majority of the operating expenses are included in the Industrial Ingredients segment’s results of operations in the Consolidated Financial Statements. Sales of $26.9 million related to the acquired Carolina Starches businesses were included in the Industrial Ingredients results of operations. Due to the integration of Carolina Starches into the Company’s two business segments, it is not practicable to determine the net earnings of Carolina Starches included in the consolidated statements of operations since the acquisition.
	Reconciliation of income (loss) from operations for the Company’s segments to income (loss) before income taxes as reported in the consolidated financial statements follows:
		Year Ended August 31,
		2013			2012			2011
		(Dollars in thousands)
	Income from operations	$	9,404		$	10,059		$	4,445
	Interest expense		(3,989	)		(8,633	)		(9,364	)
	Other non-operating income (expense)		75			(6,186	)		115
	Income (loss) before income taxes	$	5,490		$	(4,760	)	$	(4,804	)
	Sales, attributed to the area to which the product was shipped, are as follows:
		Year Ended August 31,
		2013			2012			2011
		(Dollars in thousands)
	United States	$	429,957		$	400,070		$	346,893
	Canada		8,662			5,653			4,027
	Mexico		11,419			12,761			9,221
	Columbia		7,379			6,678			6,802
	Japan		5,112			4,380			3,434
	Other		4,721			3,609			3,386
	Non-United States		37,293			33,081			26,870
	Total	$	467,250		$	433,151		$	373,763

Quarterly_Financial_Data_Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Aug. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Quarterly Financial Data (Unaudited)	'
	Note 20 — Quarterly Financial Data (Unaudited)
	The following tables set forth selected unaudited consolidated quarterly financial information for the Company’s two most recent fiscal years.
	Fiscal 2013	First		Second			Third			Fourth			Total
		Quarter		Quarter			Quarter			Quarter
		(Dollars in thousands, except per share data)
	Sales	$	118,022	$	110,082		$	121,719		$	117,427		$	467,250
	Cost of sales		104,764		99,081			108,528			109,830			422,203
	Gross margin		13,258		11,001			13,191			7,597			45,047
	Net income (loss)		1,707		1,191			2,058			(949	)		4,007
	Earnings (loss) per common share:
	Basic	$	0.14	$	0.1		$	0.17		$	(0.08	)	$	0.32
	Diluted	$	0.14	$	0.1		$	0.16		$	(0.08	)	$	0.32
	Dividends declared		$      -		$      -			$      -			$      -			$      -
	Fiscal 2012	First		Second			Third			Fourth			Total
		Quarter		Quarter			Quarter			Quarter
		(Dollars in thousands, except per share data)
	Sales	$	108,168	$	103,477		$	111,283		$	110,223		$	433,151
	Cost of sales		96,360		94,076			99,829			98,976			389,241
	Gross margin		11,808		9,401			11,454			11,247			43,910
	Net income (loss)		592		(340	)		(5,452	)		(4,366	)		(9,566	)
	Earnings (loss) per common share:
	Basic	$	0.05	$	(0.03	)	$	(0.44	)	$	(0.35	)	$	(0.78	)
	Diluted	$	0.05	$	(0.03	)	$	(0.44	)	$	(0.35	)	$	(0.78	)
	Dividends declared		$      -		$      -			$      -			$      -			$      -
	In the fourth quarter of fiscal 2012, the Company redeemed $28.9 million of its outstanding Series A Preferred Stock at the original issue price of $23.5 million plus accrued dividends of $5.4 million. As a result of the early redemption, the Company recorded accelerated discount accretion of $3.2 million and amortization of issuance costs of $0.6 million as a loss on redemption in other non-operating income (expense). See Note 6.

Legal_Proceedings_and_Continge

Legal Proceedings and Contingencies	12 Months Ended
	Aug. 31, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Legal Proceedings and Contingencies	'
	Note 21 – Legal Proceedings and Contingencies
	In June 2011, the Company was notified that a complaint had been filed against a customer of a Company subsidiary, Penford Products Co. (“Penford Products”), in the United States District Court for the District of New Jersey alleging that certain pet products supplied by Penford Products to the customer by infringed upon a patent owned by T.F.H. Publications, Inc. (“Plaintiff”). The customer tendered the defense of this lawsuit to Penford Products pursuant to the terms of its supply agreement with Penford Products, and Penford Products commenced a defense at that time. In April 2012, the Plaintiff filed an amended complaint alleging that certain additional products made by Penford Products for the same customer infringed upon two of Plaintiff’s patents. The complaint seeks an injunction against infringement of the Plaintiff’s patents as well as the recovery of certain damages. The court held a claim construction hearing on August 7, 2013 and the Company is awaiting the court’s decision regarding certain disputed patent claim terms. In November 2013 Plaintiff filed an amended complaint adding Penford Products as a defendant in the case. The Company believes that its products do not infringe upon any of Plaintiff’s patents and has continued its defense of the lawsuit. The Company cannot at this time determine the likelihood of any outcome or estimate any damages that might be awarded.
	In late August and early September, 2013, two of the Company’s subsidiaries, Penford Products and Carolina Starches, LLC (“Carolina Starches”), were served with separate complaints filed by Pirinate Consulting Group, LLC, as Litigation Trustee for the NP Creditor Litigation Trust, a successor in interest to the bankruptcy estate of NewPage Corporation, in the United States Bankruptcy Court for the District of Delaware seeking damages arising from alleged preferential transfers. The complaint filed against Penford Products seeks the recovery of alleged preferential transfers in the amount of approximately $778,000, together with other damages. The complaint filed against Carolina Starches seeks recovery of alleged preferential transfers of approximately $216,000, together with other damages. Answers to these complaints are not yet due and have not been filed, and no discovery in these matters has yet occurred. The Company believes that it has adequate, well-recognized defenses to these claims; however, the Company cannot at this time determine the likelihood of any outcome or estimate any damages that might be awarded.
	In the third quarter of fiscal year 2013, the Company received $3.4 million in full settlement of certain claims the Company had made against a contractor and its insurer that arose from engineering design work performed in connection with the construction of the Company’s ethanol plant completed in 2008. The Company had alleged breach of contract and negligence by the contractor, and sought recovery of its costs and damages from the contractor and its insurer due to errors and delays in the performance of the work. The settlement amount, net of contingent legal fees, expert fees and other litigation expenses incurred in the matter, of approximately $2.1 million, was reflected as a reduction of the cost of the ethanol plant. Approximately $0.3 million was recorded as a reduction of operating expenses related to the recovery of legal and other costs.
	The Company sold its Australia/New Zealand Operations in fiscal year 2010. Proceeds from the sale of the Australia/New Zealand Operations included $2.0 million placed in escrow, approximately $1.225 million of which had been distributed to the Company’s subsidiary, Penford Australia Limited (“Penford Australia”) prior to fiscal year 2013. In August 2012, the purchaser of the Company’s Lane Cove, New South Wales, Australia operating assets submitted a statement to an agreed-upon arbitrator in which it indicated that the total value of its warranty claims amounted to approximately $901,000, including certain taxes. During the second quarter of fiscal year 2013, the arbitrator denied most of the purchaser’s warranty claims. As a result of this determination and the terms of the asset sale contract with the purchaser, Penford Australia received all of the remaining escrowed funds during the second quarter of fiscal year 2013.
	The Company regularly evaluates the status of claims and legal proceedings in which it is involved in order to assess whether a loss is probable or there is a reasonable possibility that a loss may have been incurred and to determine if accruals are appropriate. For the matters identified in the first two paragraphs, management is unable to provide additional information regarding any possible loss because (i) the Company currently believes that the claims are not adequately supported, and (ii) there are significant factual issues to be resolved. With regard to these matters, management does not believe, based on currently available information, that the eventual outcomes will have a material adverse effect on the Company’s financial condition, although the outcomes could be material to the Company’s operating results for any particular period, depending, in part, upon the operating results for such period.
	The Company is involved from time to time in various other claims and litigation arising in the normal course of business. The Company expenses legal costs as incurred. In the judgment of management, which relies in part on information obtained from the Company’s outside legal counsel, the ultimate resolution of these other matters will not materially affect the consolidated financial position, results of operations or liquidity of the Company.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Aug. 31, 2013
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying consolidated financial statements include the accounts of Penford and its wholly owned subsidiaries. All material intercompany balances and transactions have been eliminated. Certain reclassifications have been made to prior years’ financial statements in order to conform to the current year presentation.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Estimates are used in accounting for, among other things, the allowance for doubtful accounts, accruals, legal contingencies, the determination of fair value of net assets acquired in a business combination, the determination of assumptions for pension and postretirement employee benefit costs, useful lives of property and equipment, the assessment of a potential impairment of goodwill or long-lived assets, and income taxes including the determination of a need for a valuation allowance for deferred tax assets. Actual results may differ from previously estimated amounts.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents
	Cash and cash equivalents consist of cash and temporary investments with maturities of less than three months when purchased. Amounts are reported in the balance sheets at cost, which approximates fair value.
Cash Overdrafts	'
	Cash Overdrafts
	Cash overdrafts represent the amount by which outstanding checks issued, but not yet presented to banks for disbursement, exceed balances on deposit in the applicable bank accounts. The changes in cash overdrafts are included as a component of cash flows from financing activities in the consolidated statements of cash flows.
Allowance for Doubtful Accounts and Concentration of Credit Risk	'
	Allowance for Doubtful Accounts and Concentration of Credit Risk
	The Company records accounts receivable at net realizable value, which includes an allowance for doubtful accounts to reflect any loss anticipated on the accounts receivable balances. The allowance for doubtful accounts reflects the Company’s best estimate of probable losses in the accounts receivable balances. Penford estimates the allowance for uncollectible accounts based on historical experience, known troubled accounts, industry trends, economic conditions, how recently payments have been received, and ongoing credit evaluations of its customers. Activity in the allowance for doubtful accounts for fiscal 2013, 2012 and 2011 is as follows (dollars in thousands):
		Balance		Charged to			Deductions			Balance
		Beginning of		Costs and			and Other			End of Year
		Year		Expenses
	Year ended August 31:
	2013	$	78	$	241		$	(39	)	$	280
	2012	$	1,305	$	(42	)	$	(1,185	)	$	78
	2011	$	350	$	958		$	(3	)	$	1,305
	Approximately 38%, 36% and 34% of the Company’s sales in fiscal 2013, 2012 and 2011, respectively, were made to customers who operate in the paper industry. This industry suffered an economic downturn, which has resulted in the closure of a number of mills. In fiscal 2011, the increase in the allowance for uncollectible accounts was related to two paper industry customers. These receivables were written off in fiscal 2012.
Inventories	'
	Inventories
	Inventories are stated at the lower of cost or net realizable value. Costs are determined using the first-in, first-out (“FIFO”) method. Capitalized costs include materials, labor and manufacturing overhead related to the purchase and production of inventories.
Property, Plant and Equipment	'
	Property, Plant and Equipment
	The Company’s property consists primarily of plants and equipment used for manufacturing activities. Property, plant and equipment are recorded at cost less accumulated depreciation. Expenditures for maintenance and repairs are expensed as incurred. The Company uses the straight-line method to compute depreciation expense over the estimated useful lives of the depreciable assets. Equipment and vehicles generally have average useful lives ranging from three to twelve years and real estate between twelve to forty-six years. Depreciation, which includes depreciation of assets under capital leases, of $12.8 million, $12.7 million and $12.8 million was recorded in fiscal years 2013, 2012 and 2011, respectively. For income tax purposes, the Company generally uses accelerated depreciation methods.
	Interest is capitalized on major construction projects while in progress. During fiscal years 2013 and 2012, the Company capitalized $107,000 and $48,000, respectively, in interest costs. No interest was capitalized in fiscal 2011.
	The Company reviews its long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Impairment is recognized when estimated expected undiscounted future cash flows are less than the carrying amount of the assets. To the extent that impairment has occurred, the excess of the carrying amount of long-lived assets over its estimated fair value would be recognized as an impairment loss charged to earnings.
Goodwill and Other Intangible Assets	'
	Goodwill and Other Intangible Assets
	Goodwill represents the excess of cost over the fair value of net assets acquired. The Company evaluates its goodwill for impairment annually as of June 1 and whenever events or circumstances make it more likely than not that impairment may have occurred. To determine whether goodwill is impaired, Penford compares the fair value of each reporting unit to that reporting unit’s carrying amount. If the fair value of the reporting unit is greater than its carrying amount goodwill is not considered impaired. If the fair value of the reporting unit is lower than its carrying amount, Penford then compares the implied fair value of the reporting unit’s goodwill with the carrying amount of that goodwill, and, if the carrying value is higher than the fair value, an impairment charge would be recorded. The implied fair value of a reporting unit is determined using a discounted cash flow method considering the Company’s market capitalization.
	Definite-lived intangible assets, primarily patents, are amortized using the straight-line method over their expected economic useful lives. At August 31, 2013, the weighted average remaining amortization period for patents is five years. Penford has no intangible assets with indefinite lives.
Accrued Liabilities	'
	Accrued Liabilities
	Components of accrued liabilities are as follows (dollars in thousands):
		August 31,
		2013		2012
	Employee-related costs	$	3,931	$	4,837
	Other		4,276		3,400
	Accrued liabilities	$	8,207	$	8,237
	Employee-related costs include accrued payroll, compensated absences, payroll taxes, benefits and incentives.
Revenue Recognition	'
	Revenue Recognition
	Revenue from sales of products and shipping and handling revenue are recognized at the time goods are shipped and title transfers to the customer. This transfer is considered complete when a sales agreement is in place, delivery has occurred, pricing is fixed or determinable and collection is reasonably assured. Proceeds from the sale of by-products from the Company’s corn wet milling operations are classified as sales in the Statements of Operations. Costs associated with shipping and handling are included in cost of sales.
Significant Customer and Export Sales	'
	Significant Customer and Export Sales
	The Company has several relatively large customers in each business segment. The Company’s sales of ethanol to its sole ethanol customer, Eco-Energy, Inc., represented approximately 21%, 24% and 28% of the Company’s net sales for fiscal years 2013, 2012 and 2011, respectively. Eco-Energy, Inc. is a marketer and distributor of biofuels in the United States and Canada, is a customer of the Company’s Industrial Ingredients business. Export sales accounted for approximately 8.0%, 7.6% and 7.2% of consolidated sales in fiscal years ended August 31, 2013, 2012 and 2011, respectively.
Derivatives	'
	Derivatives
	Penford uses derivative instruments to manage the exposures associated with commodity prices, interest rates and energy costs. The derivative instruments are reported at fair value in other current assets or current liabilities in the consolidated balance sheets. The Company offsets the fair value amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral arising from derivative instruments recognized at fair value executed with the same counterparty under a master netting arrangement.
	For derivative instruments designated and qualifying as fair value hedges, the gain or loss on the derivative instruments as well as the offsetting gain or loss on the hedged firm commitments or inventory are recognized in current earnings as a component of cost of goods sold. For derivative instruments designated and qualifying as cash flow hedges, the effective portion of the gain or loss on the derivative instruments is reported as a component of other comprehensive income (loss), net of applicable income taxes, and recognized in earnings when the hedged exposure affects earnings. The Company recognizes the gain or loss on the derivative instrument as a component of cost of goods sold in the period when the finished goods produced from the hedged item are sold or, for interest rate swaps, as a component of interest expense in the period the forecasted transaction is reported in earnings. If it is determined that the derivative instruments used are no longer effective at offsetting changes in cash flows or fair value of the hedged item, then the changes in fair value would be recognized in current earnings as a component of cost of good sold or interest expense.
Research and Development	'
	Research and Development
	Research and development costs are expensed as incurred, except for costs of patents, which are capitalized and amortized over the lives of the patents. The Company’s research and development expenditures primarily consists of internal salaries, wages, consulting and supplies attributable to time spent on research and development activities. Other costs include depreciation and maintenance of research and development facilities and equipment, including assets at manufacturing locations that are engaged in pilot plant activities. Research and development costs expensed were $5.9 million, $5.8 million and $4.8 million in fiscal 2013, 2012 and 2011, respectively.
Stock-Based Compensation	'
	Stock-Based Compensation
	The Company has a long-term incentive plan that provides for stock-based compensation, including the granting of stock options and shares of restricted stock to employees and directors. The Company utilizes the Black-Scholes option-pricing model to determine the fair value of stock options on the date of grant. This model derives the fair value of stock options based on certain assumptions related to expected stock price volatility, expected option life, risk-free interest rate and dividend yield. The grant date fair value of restricted stock awards is equal to the market price of the Company’s common stock at the grant date.
	The Company recognizes stock-based compensation expense utilizing the accelerated multiple options approach over the requisite service period, which equals the vesting period. See Note 11 for further detail.
Income Taxes	'
	Income Taxes
	The provision for income taxes includes federal and state taxes currently payable and deferred income taxes arising from temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured pursuant to tax laws using the rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The impact on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the date of enactment.
	A valuation allowance is provided to the extent that it is more likely than not that deferred tax assets will not be realized. Tax benefits from uncertain tax positions are recognized when it is more likely than not that the position will be sustained upon examination based on the technical merits of the position. The amount recognized is measured as the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon settlement. The Company recognizes interest and penalty expense associated with uncertain tax positions as a component of income tax expense.
	The Company has not provided deferred taxes related to its investment in foreign subsidiaries, which are classified as discontinued operations, as it does not expect future distributions from the subsidiaries or repayments of permanent advances.
Foreign Currency	'
	Foreign Currency
	Assets and liabilities of subsidiaries whose functional currency is deemed to be other than the U.S. dollar are translated at year end rates of exchange. Resulting translation adjustments are accumulated in the currency translation adjustments component of other comprehensive income. Statement of operations amounts are translated at average exchange rates prevailing during the year. Foreign currency transaction gains or losses in fiscal years 2013, 2012 and 2011 were not significant.
Acquisitions	'
	Acquisitions
	Acquisitions of businesses are accounted for using the acquisition method of accounting and the financial statements include the results of the acquired operations from the date of acquisition. The purchase price of the acquired entity is allocated to the net assets acquired and net liabilities assumed based on the estimated fair value at the date of acquisition. The excess of cost over the fair value of the net assets acquired is recognized as goodwill.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In June 2011, the Financial Accounting Standards Board (“FASB”) issued guidance requiring entities to present the total of comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. The amendment did not change the items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income under current accounting standards. The guidance was effective for the Company’s fiscal year and interim periods beginning September 1, 2012. The Company adopted this amended guidance in fiscal 2013 and presented the Consolidated Statements of Comprehensive Income (Loss) immediately following the Consolidated Statements of Operations.
	In February 2013, the FASB issued guidance requiring entities to provide information about the amounts reclassified out of accumulated other comprehensive income by component. Entities are required to present, either on the face of the financial statements or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income. This guidance, which is effective prospectively for annual reporting periods’ beginning after December 15, 2012, does not change the current requirements for reporting net income or other comprehensive income. The Company is evaluating the impact this guidance will have on its disclosures.
	In December 2011, the FASB issued guidance creating new disclosure requirements about the nature of an entity’s rights of setoff and related arrangements associated with its financial instruments and derivative instruments. The disclosure requirements are effective for annual reporting periods, and interim reporting periods within those years, beginning on or after January 1, 2013 (fiscal 2014 for Penford). The Company is evaluating the impact this update will have on its disclosures.
	In July 2013, the FASB issued guidance designed to reduce diversity in practice of financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. This guidance is effective for fiscal years, and interim reporting periods within those years, beginning after December 15, 2013 (fiscal 2015 for Penford). The Company does not expect this guidance to have a material effect on its financial position, results of operations or liquidity.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Aug. 31, 2013
Accounting Policies [Abstract]	'
Allowance for Doubtful Accounts Activity	'
	Activity in the allowance for doubtful accounts for fiscal 2013, 2012 and 2011 is as follows (dollars in thousands):
		Balance		Charged to			Deductions			Balance
		Beginning of		Costs and			and Other			End of Year
		Year		Expenses
	Year ended August 31:
	2013	$	78	$	241		$	(39	)	$	280
	2012	$	1,305	$	(42	)	$	(1,185	)	$	78
	2011	$	350	$	958		$	(3	)	$	1,305
Components of accrued liabilities	'
	Components of accrued liabilities are as follows (dollars in thousands):
		August 31,
		2013		2012
	Employee-related costs	$	3,931	$	4,837
	Other		4,276		3,400
	Accrued liabilities	$	8,207	$	8,237

Inventories_Tables

Inventories (Tables)	12 Months Ended
	Aug. 31, 2013
Inventory Disclosure [Abstract]	'
Components of Inventory	'
	Components of inventory are as follows:
		August 31,
		2013		2012
		(Dollars in thousands)
	Raw materials	$	10,381	$	19,773
	Work in progress		1,913		1,542
	Finished goods		21,698		22,357
	Total inventories	$	33,992	$	43,672

Property_and_equipment_Tables

Property and equipment (Tables)	12 Months Ended
	Aug. 31, 2013
Property Plant And Equipment [Abstract]	'
Components of Property and Equipment	'
	Components of property and equipment are as follows:
		August 31,
		2013			2012
		(Dollars in thousands)
	Land and land improvements	$	11,881		$	11,623
	Plant and equipment		359,909			346,087
	Construction in progress		5,255			7,679
			377,045			365,389
	Accumulated depreciation		(264,904	)		(252,198	)
	Net property and equipment	$	112,141		$	113,191

Goodwill_and_other_intangible_1

Goodwill and other intangible assets (Tables)	12 Months Ended
	Aug. 31, 2013
Goodwill And Intangible Assets Disclosure [Abstract]	'
Carrying Amount and Accumulated Amortization of Intangible Assets	'
	The carrying amount and accumulated amortization of intangible assets are as follows (dollars in thousands):
		August 31, 2013				August 31, 2012
		Carrying		Accumulated		Carrying		Accumulated
		Amount		Amortization		Amount		Amortization
	Intangible assets:
	Patents	$	1,748	$	1,538	$	1,748	$	1,500
	Customer lists		190		154		190		59
	Non-compete agreements		100		33		100		12
	Other intangible assets	$	2,038	$	1,725	$	2,038	$	1,571

Debt_Tables

Debt (Tables)	12 Months Ended
	Aug. 31, 2013
Debt Disclosure [Abstract]	'
Long-term Debt and Capital Lease Obligations Current and Non Current	'
		August 31,
		2013		2012
		(Dollars in thousands)
	Secured credit agreements — revolving loans, 3.18% weighted average interest rate at August 31, 2013	$	71,506	$	82,606
	Iowa Department of Economic Development loans		1,233		1,433
	Capital lease obligations		231		423
			72,970		84,462
	Less: current portion and short-term borrowings		231		458
	Long-term debt and capital lease obligations	$	72,739	$	84,004
Schedule of Maturities of Long-term Debt	'
	The maturities of debt existing at August 31, 2013 for the fiscal years beginning with fiscal 2014 are as follows (dollars in thousands):
	2014	$	231
	2015		1,103
	2016		57
	2017		71,554
	2018		25
		$	72,970

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	12 Months Ended
	Aug. 31, 2013
Equity [Abstract]	'
Common Shares Outstanding	'
	Common Stock
		Year Ended August 31,
		2013		2012		2011
	Common shares outstanding
	Balance, beginning of year		14,280,718		13,243,385		13,189,581
	Series B preferred stock converted to common shares		-		1,000,000		-
	Exercise of stock options		121,226		-		-
	Issuance of restricted stock, net		52,237		37,333		53,804
	Balance, end of year		14,454,181		14,280,718		13,243,385

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Aug. 31, 2013
Text Block [Abstract]	'
Components of Accumulated Other Comprehensive Income (Loss)	'
	The components of accumulated other comprehensive loss and other comprehensive income (loss) are summarized below. The components of other comprehensive income (loss) and the income tax expense (benefit) allocated to each component of other comprehensive income (loss), including reclassification adjustments, are presented in the Consolidated Statements of Comprehensive Income (Loss).
	(In thousands)	Net Unrealized			Gains (Losses)			Accumulated
		Gains (Losses)			on			Other
		on Cash Flow			Postretirement			Comprehensive
		Hedging			Obligations			Loss
		Instruments
	Balance at August 31, 2010	$	(582	)	$	(13,268	)	$	(13,850	)
	Other comprehensive income (loss), net of taxes		1,313			4,978			6,291
	Balance at August 31, 2011		731			(8,290	)		(7,559	)
	Other comprehensive income (loss), net of taxes		907			(8,941	)		(8,034	)
	Balance at August 31, 2012		1,638			(17,231	)		(15,593	)
	Other comprehensive income (loss), net of taxes		(2,494	)		10,468			7,974
	Balance at August 31, 2013	$	(856	)	$	(6,763	)	$	(7,619	)

Leases_Tables

Leases (Tables)	12 Months Ended
	Aug. 31, 2013
Leases [Abstract]	'
Future Minimum Lease Payments for Noncancelable Operating and Capital Leases	'
	Future minimum lease payments for fiscal years beginning with fiscal year 2014 for noncancelable operating leases and capital leases having initial lease terms of more than one year are as follows (dollars in thousands):
		Capital			Operating Leases
		Leases			Minimum Lease
					Payments
	2014	$	70		$	2,836
	2015		69			1,701
	2016		67			942
	2017		52			448
	2018		17			41
	Thereafter		9			-
	Total minimum lease payments		284		$	5,968
	Less: amounts representing interest		(53	)
	Net minimum lease payments	$	231

Stockbased_Compensation_Plans_

Stock-based Compensation Plans (Tables)	12 Months Ended
	Aug. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Schedule of Share Based Compensation Stock Options Activity	'
	A summary of the stock option activity for the year ended August 31, 2013 is as follows:
		Number			Option Price			Weighted			Weighted		Aggregate
		of			Range			Average			Average		Intrinsic
		Shares						Exercise			Remaining		Value
								Price			Term (in
											years)
	Outstanding Balance, August 31, 2012		1,824,916		$	4.66 — 21.73		$	10.94
	Granted		120,000			7.60 — 11.09			8.49
	Exercised		(222,864	)		5.29 — 12.79			10.31
	Cancelled		(204,464	)		9.87 — 17.07			14.99
	Outstanding Balance, August 31, 2013		1,517,588			4.66 — 21.73			10.3			3.9	$	6,737,300
	Options Exercisable at August 31, 2013		895,339		$	4.66 — 21.73		$	13.17			2.74	$	2,144,000
Schedule of Share Based Payment Award Stock Options Valuation Assumptions	'
	The Company estimated the fair value of stock options granted using the following weighted-average assumptions and resulting in the following weighted-average grant date fair value:
		2013		2012	2011
	Expected volatility	68%		68%	71%
	Expected life (years)	4.7		4.9	4.3
	Interest rate	0.5 -1.0%		0.5 -1.1%	1.1-2.8%
	Dividend yield	0%		0%	0%
	Weighted-average fair values	$4.60		$3.13	$3.62
Schedule of Share-Based Compensation, Restricted Stock Award Activity	'
	The following table summarizes the restricted stock award activity for the twelve months ended August 31, 2013 as follows:
		Number of			Weighted
		Shares			Average
					Grant Date
					Fair Value
	Nonvested at August 31, 2012		61,716		$	5.94
	Granted		24,489			7.35
	Vested		(61,716	)		5.94
	Cancelled		-
	Nonvested at August 31, 2013		24,489		$	7.35
Schedule of Employee Service Share-Based Compensation, Allocation of Recognized Period Costs	'
	The following table summarizes the total stock-based compensation cost for fiscal years 2013, 2012 and 2011 and the effect on the Company’s consolidated statements of operations (dollars in thousands):
		2013			2012			2011
	Cost of sales	$	-		$	48		$	130
	Operating expenses		1,404			1,324			949
	Research and development expenses		-			15			38
	Total stock-based compensation expense	$	1,404		$	1,387		$	1,117
	Income tax benefit		(534	)		(527	)		(424	)
	Total stock-based compensation expense, net of tax	$	870		$	860		$	693

Pensions_and_Other_Postretirem1

Pensions and Other Postretirement Benefits (Tables)	12 Months Ended
	Aug. 31, 2013
Compensation And Retirement Disclosure [Abstract]	'
Summary of Pension and Other Postretirement Benefit Plans	'
	The following represents information summarizing the Company’s pension and other postretirement benefit plans. A measurement date of August 31, 2013 was used for all plans.
		Year Ended August 31,
		Pension Benefits						Other Benefits
		2013			2012			2013			2012
		(Dollars in thousands)
	Change in benefit obligation:
	Benefit obligation at September 1	$	62,989		$	47,545		$	20,457		$	16,924
	Service cost		1,945			1,521			235			229
	Interest cost		2,648			2,729			860			972
	Plan participants’ contributions		—			—			106			119
	Amendments		—			212			—			—
	Actuarial (gain) loss		(107	)		619			267			(170	)
	Change in assumptions		(8,135	)		12,359			(3,912	)		3,024
	Benefits paid		(2,062	)		(1,996	)		(657	)		(641	)
	Benefit obligation at August 31	$	57,278		$	62,989		$	17,356		$	20,457
	Change in plan assets:
	Fair value of plan assets at September 1	$	42,072		$	36,328		$	—		$	—
	Actual return on plan assets		5,580			3,688			—			—
	Company contributions		1,136			4,052			551			522
	Plan participants’ contributions		—			—			106			119
	Benefits paid		(2,062	)		(1,996	)		(657	)		(641	)
	Fair value of the plan assets at August 31	$	46,726		$	42,072		$	—		$	—
	Funded status:
	Net liability – Plan assets less than projected benefit obligation	$	(10,552	)	$	(20,917	)	$	(17,356	)	$	(20,457	)
	Recognized as:
	Current accrued benefit liability	$	—		$	—		$	(760	)	$	(750	)
	Non-current accrued benefit liability		(10,552	)		(20,917	)		(16,596	)		(19,707	)
	Net Amount Recognized	$	(10,552	)	$	(20,917	)	$	(17,356	)	$	(20,457	)
Components of Accumulated Other Comprehensive Loss Unrecognized	'
	Accumulated other comprehensive loss consists of the following amounts that have not yet been recognized as components of net benefit cost (dollars in thousands):
		August 31, 2013						August 31, 2012
		Pension			Other			Pension			Other
		Benefits			Benefits			Benefits			Benefits
	Unrecognized prior service cost (credit)	$	1,288		$	(155	)	$	1,529		$	(307	)
	Unrecognized net actuarial loss		10,091			(318	)		22,976			3,594
	Total	$	11,379		$	(473	)	$	24,505		$	3,287
Benefit Obligations in Excess of Fair Value of Plan Assets	'
	Selected information related to the Company’s defined benefit pension plans that have benefit obligations in excess of fair value of plan assets is presented below (dollars in thousands):
		August 31,
		2013			2012
	Projected benefit obligation	$	57,278		$	62,989
	Accumulated benefit obligation	$	54,389		$	59,853
	Fair value of plan assets	$	46,726		$	42,072
Components of Net Periodic Benefit Cost	'
	Net Periodic Benefit Cost
		Year Ended August 31,
		Pension Benefits									Other Benefits
		2013			2012			2011			2013			2012			2011
		(Dollars in thousands)
	Components of net periodic benefit cost
	Service cost	$	1,945		$	1,521		$	1,617		$	235		$	229		$	272
	Interest cost		2,648			2,729			2,696			860			972			972
	Expected return on plan assets		(2,869	)		(2,914	)		(2,234	)		—			—			—
	Amortization of prior service cost		241			228			228			(152	)		(152	)		(152	)
	Amortization of actuarial loss		1,932			773			1,441			267			—			65
	Benefit cost	$	3,897		$	2,337		$	3,748		$	1,210		$	1,049		$	1,157
Benefit Plan Assumptions	'
	Assumptions
	The Company assesses its benefit plan assumptions on a regular basis. Assumptions used in determining plan information are as follows:
		August 31,
		Pension Benefits									Other Benefits
		2013			2012			2011			2013			2012			2011
	Weighted-average assumptions used to calculate net periodic expense:
	Discount rate		4.28	%		5.87	%		5.64	%		4.28	%		5.87	%		5.64	%
	Expected return on plan assets		7	%		8	%		8	%
	Rate of compensation increase		3	%		3	%		4	%
	Weighted-average assumptions used to calculate benefit obligations at August 31:
	Discount rate		5.24	%		4.28	%		5.87	%		5.24	%		4.28	%		5.87	%
	Expected return on plan assets		7	%		7	%		8	%
	Rate of compensation increase		3	%		3	%		3	%
Assumed Health Care Cost Trend Rates	'
	Assumed health care cost trend rates:		2013			2012			2011
	Current health care trend assumption		7.8	%		8	%		8	%
	Ultimate health care trend rate		4.5	%		4.5	%		4.5	%
	Year ultimate health care trend is reached		2032			2030			2029
Effect of Changes in Assumed Health Care Cost Trend Rate	'
	The assumed health care cost trend rate could have a significant effect on the amounts reported. A one-percentage-point change in the assumed health care cost trend rate would have the following effects:
		1-Percentage-			1-Percentage-
		Point			Point
		Increase			Decrease
		(Dollars in thousands)
	Effect on total of service and interest cost components in fiscal 2013	$	182		$	(146	)
	Effect on postretirement accumulated benefit obligation as of August 31, 2013	$	2,405		$	(1,999	)
Weighted Average Asset Allocations of Investment Portfolio for Pension Plans	'
	The weighted average asset allocations of the investment portfolio for the pension plans at August 31 are as follows:
		Target			August 31,
		Allocation			2013			2012
	U.S. equities		55	%		55	%		56	%
	International equities		15	%		15	%		15	%
	Fixed income investments		25	%		25	%		24	%
	Real estate		5	%		5	%		5	%
Fair Value of Pension Plan's Assets by Major Asset Category	'
	The following table presents the fair value of the pension plan’s assets by major asset category as of August 31, 2013.
		Quoted Prices			Significant			Significant			Total
		In Active			Other			Unobservable
		Markets for			Observable			Inputs
		Identical			Inputs			(Level 3)
		Instruments			(Level 2)
		(Level 1)
		(in thousands)
	Common collective trust funds	$			$	44,378		$	-		$	44,378
	Real estate equity funds		-			-			2,348			2,348
	Fair value of plan assets	$	-		$	44,378		$	2,348		$	46,726
Changes in Fair Value of Pension Plan's Real Estate Equity Fund	'
	The following table summarizes the changes in fair value of the pension plan’s real estate equity fund (Level 3) for fiscal year ended August 31, 2013.
		Real Estate
		Equity Fund
		(in thousands)
	Balance, August 31, 2012	$	2,102
	Actual return on plan assets:
	Relating to assets still held at the reporting date		246
	Relating to assets sold during the period		-
	Purchases and sales		-
	Transfers in (out) of Level 3		-
	Balance, August 31, 2013	$	2,348
Expected Benefit Payments	'
	Expected benefit payments are based on the same assumptions used to measure the benefit obligations and include benefits attributable to estimate future employee service.
		Pension			Other
					Postretirement
		(Dollars in millions)
	2014	$	2.4		$	0.9
	2015		2.5			1
	2016		2.6			1
	2017		2.8			1.1
	2018		3			1.2
	2019-2023	$	18.7		$	7.7

Fair_Value_Measurements_and_De1

Fair Value Measurements and Derivative Instruments (Tables)	12 Months Ended
	Aug. 31, 2013
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'
Fair Values of Company's Derivative Instruments	'
	Presented below are the fair values of the Company’s derivative instruments as of August 31, 2013 and 2012:
	As of August 31, 2013	(Level 1)				(Level 2)				(Level 3)			Total
		(in thousands)
	Current assets (Other Current Assets):
	Commodity derivatives (1)	$	512			$	-			$	-		$	512
	(1) On the consolidated balance sheets, commodity derivative assets and liabilities have been offset by cash collateral due and paid under master netting arrangements which are recorded together in Other Current Assets. The cash collateral offset was $1.7 million at August 31, 2013.
	As of August 31, 2012	(Level 1)				(Level 2)				(Level 3)			Total
		(in thousands)
	Current assets (Other Current Assets):
	Commodity derivatives (1)	$	(1,422)			$	-			$	-		$	(1,422)
	(1) On the consolidated balance sheets, commodity derivative assets and liabilities have been offset by cash collateral due and paid under master netting arrangements which are recorded together in Other Current Assets. The cash collateral offset was $2.6 million at August 31, 2012.
Outstanding Futures Contracts	'
	As of August 31, 2013, the Company had the following outstanding futures contracts:
	Corn Futures		4,190,000				Bushels
	Ethanol Swaps		7,350,000				Gallons
Fair Values of Company's Derivatives by Contract Type	'
	The following tables provide information about the fair values of the Company’s derivatives, by contract type, as of August 31, 2013 and 2012.
		Assets										Liabilities
	In thousands			Fair Value August 31									Fair Value August 31
		Balance Sheet		2013				2012				Balance Sheet	2013			2012
		Location										Location
	Derivatives designated as hedging instruments:
	Cash Flow Hedges:
	Corn Futures	Other Current Assets		$	-			$	12			Other Current Assets	$	485		$	126
	Ethanol Futures	Other Current Assets			997				-			Other Current Assets		-			706
	Fair Value Hedges:
	Corn Futures	Other Current Assets			-				-			Other Current Assets		-			602
				$	997			$	12				$	485		$	1,434
Effect of Derivative Instruments on Company's Financial Performance	'
	The following tables provide information about the effect of derivative instruments on the financial performance of the Company for the fiscal years ended August 31, 2013, 2012 and 2011.
	In thousands	Amount of Gain (Loss)											Amount of Gain (Loss)									Amount of Gain (Loss)
		Recognized in AOCI											Reclassified from									Recognized in Income
													AOCI into Income
		Year Ended August 31											Year Ended August 31									Year Ended August 31
		2013				2012				2011			2013			2012			2011			2013			2012			2011
	Derivatives designated as hedging instruments:
	Cash Flow Hedges:
	Corn Futures (1)	$	(407	)		$	2,067			$	(4,949	)	$	5,351		$	1,500		$	(7,418	)	$	(870	)	$	36		$	(162	)
	Natural Gas Futures (1)		-				-				(579	)		-			(492	)		(1,332	)		-			-			(85	)
	Ethanol Futures (1)		1,611				1,667				(4,180	)		(123	)		1,263			(3,075	)		(151	)		-			-
		$	1,204			$	3,734			$	(9,708	)	$	5,228		$	2,271		$	(11,825	)	$	(1,021	)	$	36		$	(247	)
	Fair Value Hedges:
	Corn Futures (1) (2)																					$	363		$	98			28
	Derivatives not designated as hedging instruments:
	Natural Gas Futures (1)																					$	94		$	(1,082	)	$	-
	FX Contracts (1)																						-			6			-
	Soybean Oil Futures (1)																						-			12			-
	Soybean Meal Futures (1)																						-			(14	)		-
																						$	94		$	(1,078	)	$	-
	(1) Gains and losses reported in cost of goods sold
	(2) Hedged items are firm commitments and inventory

Other_Nonoperating_Income_Expe1

Other Non-operating Income (Expense) (Tables)	12 Months Ended
	Aug. 31, 2013
Other Income And Expenses [Abstract]	'
Other Non-Operating Income (Expense)	'
	Other non-operating income (expense) consists of the following:
		Year Ended August 31,
		2013		2012			2011
		(Dollars in thousands)
	Loss on redemption of Series A Preferred Stock	$	—	$	(6,599	)	$	—
	Other		75		413			115
		$	75	$	(6,186	)	$	115

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Aug. 31, 2013
Income Tax Disclosure [Abstract]	'
Schedule of U.S. Income Tax Expense (Benefit)	'
	U.S. Income tax expense (benefit) consists of the following:
		Year Ended August 31,
		2013			2012			2011
		(Dollars in thousands)
	Current:
	Federal	$	(422	)	$	(162	)	$	34
	State		80			3			137
			(342	)		(159	)		171
	Deferred:
	Federal		1,829			4,582			9
	State		(4	)		383			133
			1,825			4,965			142
	Total		$1,483			$4,806			$313
Schedule of Allocable Comprehensive Tax Expense (Benefit)	'
		Year Ended August 31,
		2013			2012			2011
		(Dollars in thousands)
	Comprehensive tax expense (benefit) allocable to:
	Income before taxes	$	1,483		$	4,806		$	313
	Comprehensive income (loss)		4,887			(4,924	)		3,856
		$	6,370		$	(118	)	$	4,169
Reconciliation of Statutory Federal Tax to Actual Provision (Benefit) for Taxes	'
	A reconciliation of the statutory federal tax to the actual provision (benefit) for taxes is as follows:
		Year Ended August 31,
		2013			2012			2011
		(Dollars in thousands)
	Statutory tax rate		35%			35%			35%
	Statutory tax on income	$	1,921		$	(1,666	)	$	(1,682	)
	State taxes, net of federal benefit		94			219			52
	Non-deductible expenses related to preferred stock		-			4,547			2,687
	Research credit		(189	)		(73	)		(195	)
	Ethanol credit		-			-			(975	)
	Foreign taxes		(183	)		(38	)		200
	Stock option exercises/expirations		376			-			-
	Prior year true up		(265	)		95			79
	Unrecognized tax benefits		(359	)		(165	)		67
	Valuation allowance		(104	)		1,787			-
	Other		192			100			80
	Total provision (benefit)	$	1,483		$	4,806		$	313
Schedule of Significant Components of Deferred Tax Assets and Liabilities	'
	The significant components of deferred tax assets and liabilities are as follows:
		August 31,
		2013			2012
		(Dollars in thousands)
	Deferred tax assets:
	Alternative minimum tax credit	$	3,473		$	3,354
	Postretirement benefits		11,920			18,060
	Provisions for accrued expenses		2,791			2,908
	Stock-based compensation		2,453			2,420
	Net operating loss carryforward		4,575			7,469
	Tax credit carryforwards		4,373			4,152
	NOL carryforward-foreign		10,853			11,010
	Hedging		525			-
	Other		2,092			2,025
			43,055			51,398
	Less - valuation allowance		(12,537	)		(12,797	)
	Total deferred tax assets		30,518			38,601
	Deferred tax liabilities:
	Depreciation		22,296			21,762
	Hedging		-			1,004
	Other		1,756			2,560
	Total deferred tax liabilities		24,052			25,326
	Net deferred tax assets	$	6,466		$	13,275
	Recognized as:
	Other current assets	$	1,479		$	167
	Deferred tax asset		4,987			13,108
	Total net deferred tax assets	$	6,466		$	13,275
Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits	'
	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (dollars in thousands):
		2013			2012
	Unrecognized tax benefits at beginning of year	$	1,058		$	1,220
	Additions for tax positions related to prior years		134			112
	Additions for tax positions related to current year		90			62
	Reductions due to lapse of applicable statute of limitations		(576	)		(336	)
	Unrecognized tax benefits at end of year	$	706		$	1,058

Earnings_loss_per_Common_Share1

Earnings (loss) per Common Share (Tables)	12 Months Ended
	Aug. 31, 2013
Earnings Per Share [Abstract]	'
Reconciliation of Income from Operations Applicable to Common Shares and Computation of Diluted Weighted Average Shares Outstanding	'
	The following table presents the reconciliation of net income (loss) to net income (loss) applicable to common shares and the computation of diluted weighted average shares outstanding for the fiscal years 2013, 2012 and 2011.
		Year Ended August 31,
		2013			2012			2011
		(in thousands)
	Numerator:
	Net income (loss)	$	4,007		$	(9,566	)	$	(5,117	)
	Less: Allocation to participating securities		(11	)		-			-
	Net income (loss) applicable to common shares and equivalents	$	3,996		$	(9,566	)	$	(5,117	)
	Denominator:
	Weighted average common shares and equivalents outstanding, basic		12,369			12,294			12,251
	Dilutive stock options and awards		249			-			-
	Weighted average common shares and equivalents outstanding, diluted		12,618			12,294			12,251

Carolina_Starches_Acquisition_

Carolina Starches Acquisition (Tables)	12 Months Ended
	Aug. 31, 2013
Business Combinations [Abstract]	'
Purchase Price Allocation to Assets Acquired and Liabilities Assumed	'
	The final allocation of the purchase price to the assets acquired and liabilities assumed, based on their fair values as of January 11, 2012, is presented below.
	(in thousands)
	Property, plant and equipment	$	3,947
	Working capital		4,225
	Other assets		141
	Intangible assets		290
	Goodwill		81
	Non-current liabilities		(184	)
	Total purchase price	$	8,500

Segment_Reporting_Tables

Segment Reporting (Tables)	12 Months Ended
	Aug. 31, 2013
Segment Reporting [Abstract]	'
Segment Wide Reporting Information	'
		Year Ended August 31,
		2013			2012			2011
		(Dollars in thousands)
	Sales
	Industrial ingredients
	Industrial Starch	$	177,382		$	156,945		$	127,471
	Ethanol		96,852			101,874			105,730
	By-products		81,782			71,788			58,322
		$	356,016		$	330,607		$	291,523
	Food ingredients		111,234			102,544			82,240
		$	467,250		$	433,151		$	373,763
	Depreciation and amortization
	Industrial ingredients	$	10,933		$	10,879		$	10,812
	Food ingredients		2,061			1,989			2,110
	Corporate and other		332			1,259			1,493
		$	13,326		$	14,127		$	14,415
	Income (loss) from operations
	Industrial ingredients	$	(3,238	)	$	(928	)	$	(4,718	)
	Food ingredients		23,265			21,591			18,037
	Corporate and other		(10,623	)		(10,604	)		(8,874	)
		$	9,404		$	10,059		$	4,445
	Capital expenditures, net
	Industrial ingredients	$	8,997		$	8,700		$	6,625
	Food ingredients		5,202			5,446			1,663
	Corporate and other		-			-			7
		$	14,199		$	14,146		$	8,295
		August 31,
		2013			2012
		(Dollars in thousands)
	Total assets
	Industrial ingredients	$	133,120		$	143,039
	Food ingredients		68,550			63,949
	Corporate and other		22,948			29,191
		$	224,618		$	236,179
Reconciliation of Income (Loss) from Operations for Segments to Income (Loss) Before Income Taxes	'
	Reconciliation of income (loss) from operations for the Company’s segments to income (loss) before income taxes as reported in the consolidated financial statements follows:
		Year Ended August 31,
		2013			2012			2011
		(Dollars in thousands)
	Income from operations	$	9,404		$	10,059		$	4,445
	Interest expense		(3,989	)		(8,633	)		(9,364	)
	Other non-operating income (expense)		75			(6,186	)		115
	Income (loss) before income taxes	$	5,490		$	(4,760	)	$	(4,804	)
Sales, Attributed to Area to Which Product was Shipped	'
	Sales, attributed to the area to which the product was shipped, are as follows:
		Year Ended August 31,
		2013			2012			2011
		(Dollars in thousands)
	United States	$	429,957		$	400,070		$	346,893
	Canada		8,662			5,653			4,027
	Mexico		11,419			12,761			9,221
	Columbia		7,379			6,678			6,802
	Japan		5,112			4,380			3,434
	Other		4,721			3,609			3,386
	Non-United States		37,293			33,081			26,870
	Total	$	467,250		$	433,151		$	373,763

Quarterly_Financial_Data_Unaud1

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Aug. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Summary of Quarterly Financial Data	'
	The following tables set forth selected unaudited consolidated quarterly financial information for the Company’s two most recent fiscal years.
	Fiscal 2013	First		Second			Third			Fourth			Total
		Quarter		Quarter			Quarter			Quarter
		(Dollars in thousands, except per share data)
	Sales	$	118,022	$	110,082		$	121,719		$	117,427		$	467,250
	Cost of sales		104,764		99,081			108,528			109,830			422,203
	Gross margin		13,258		11,001			13,191			7,597			45,047
	Net income (loss)		1,707		1,191			2,058			(949	)		4,007
	Earnings (loss) per common share:
	Basic	$	0.14	$	0.1		$	0.17		$	(0.08	)	$	0.32
	Diluted	$	0.14	$	0.1		$	0.16		$	(0.08	)	$	0.32
	Dividends declared		$      -		$      -			$      -			$      -			$      -
	Fiscal 2012	First		Second			Third			Fourth			Total
		Quarter		Quarter			Quarter			Quarter
		(Dollars in thousands, except per share data)
	Sales	$	108,168	$	103,477		$	111,283		$	110,223		$	433,151
	Cost of sales		96,360		94,076			99,829			98,976			389,241
	Gross margin		11,808		9,401			11,454			11,247			43,910
	Net income (loss)		592		(340	)		(5,452	)		(4,366	)		(9,566	)
	Earnings (loss) per common share:
	Basic	$	0.05	$	(0.03	)	$	(0.44	)	$	(0.35	)	$	(0.78	)
	Diluted	$	0.05	$	(0.03	)	$	(0.44	)	$	(0.35	)	$	(0.78	)
	Dividends declared		$      -		$      -			$      -			$      -			$      -

Business_Additional_Informatio

Business - Additional Information (Detail) (USD $)	12 Months Ended	1 Months Ended
In Millions, unless otherwise specified	Aug. 31, 2013	Jan. 31, 2012
	Segment	Carolina Starches, LLC [Member]
Business And Organization [Line Items]	'	'
Number of segments	2	'
Purchase price	'	$8.50

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Allowance for Doubtful Accounts and Concentration of Credit Risk (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Accounting Policies [Abstract]	'	'	'
Balance Beginning of Year	$78	$1,305	$350
Charged to Costs and Expenses	241	-42	958
Deductions and Other	-39	-1,185	-3
Balance End of Year	$280	$78	$1,305

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Schedule Of Significant Accounting Policies [Line Items]	'	'	'
Depreciation of assets	$13,326,000	$14,127,000	$14,415,000
Interest capitalized	107,000	48,000	0
Weighted average remaining amortization period (in years)	'4 years	'	'
Intangible assets with indefinite lives	0	'	'
Research and development costs expensed	5,870,000	5,838,000	4,772,000
Minimum percentage likelihood of tax benefit to be realized	50.00%	'	'
Real Estate [Member]	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'
Depreciation of assets	$12,800,000	$12,700,000	$12,800,000
Minimum [Member] | Equipment and Vehicles [Member]	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'
Average useful life (in years)	'3 Years	'	'
Minimum [Member] | Real Estate [Member]	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'
Average useful life (in years)	'12 years	'	'
Maximum [Member] | Equipment and Vehicles [Member]	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'
Average useful life (in years)	'12 Years	'	'
Maximum [Member] | Real Estate [Member]	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'
Average useful life (in years)	'46 years	'	'
Eco Energy, Inc [Member] | Sales Revenue, Goods, Net [Member]	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'
Concentration of sales (in percentage)	21.00%	24.00%	28.00%
Export Distribution Channel [Member] | Sales Revenue, Goods, Net [Member]	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'
Concentration of sales (in percentage)	8.00%	7.60%	7.20%
Patents [Member]	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'
Weighted average remaining amortization period (in years)	'5 years	'	'
Paper Industry [Member] | Customer Concentration Risk [Member] | Sales Revenue, Goods, Net [Member]	'	'	'
Schedule Of Significant Accounting Policies [Line Items]	'	'	'
Concentration of sales (in percentage)	38.00%	36.00%	34.00%
Number of customers in paper industry primarily responsible for increase in allowance for doubtful accounts (in customers)	2	'	'

Summary_of_Significant_Account5

Summary of Significant Accounting Policies - Components of Accrued Liabilities (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, unless otherwise specified
Accounting Policies [Abstract]	'	'
Employee-related costs	$3,931	$4,837
Other	4,276	3,400
Accrued liabilities	$8,207	$8,237

Inventories_Components_of_Inve

Inventories - Components of Inventory (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Raw materials	$10,381	$19,773
Work in progress	1,913	1,542
Finished goods	21,698	22,357
Total inventories	$33,992	$43,672

Property_and_Equipment_Compone

Property and Equipment - Components of Property and Equipment (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, unless otherwise specified
Property, Plant and Equipment [Line Items]	'	'
Property, plant and equipment, gross	$377,045	$365,389
Accumulated depreciation	-264,904	-252,198
Net property and equipment	112,141	113,191
Land and land improvements [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant and equipment, gross	11,881	11,623
Plant and equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant and equipment, gross	359,909	346,087
Construction in progress [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property, plant and equipment, gross	$5,255	$7,679

Property_and_Equipment_Additio

Property and Equipment - Additional Information (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Millions, unless otherwise specified
Property Plant And Equipment [Abstract]	'	'
Equipment under capital leases	$0.80	$1
Payables related to property, plant and equipment	$0.70	$1.10

Recovered_Sheet1

Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended					12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2013	31-May-13	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2013	Aug. 31, 2013	Aug. 31, 2013
			Food Ingredients [Member]	Food Ingredients [Member]	Food Ingredients [Member]	Maximum [Member]	Customer Lists [Member]	Non-Compete Agreements [Member]	Patents [Member]
Goodwill And Other Intangible Assets [Line Items]	'	'	'	'	'	'	'	'	'
Goodwill	$7,978,000	$7,978,000	$8,000,000	'	$8,000,000	'	'	'	'
Additions to goodwill	0	'	'	'	'	'	'	'	'
Intangible asset residual value	'	'	'	'	'	'	'	'	0
Impairment to the recorded value of goodwill	'	'	'	0	'	'	'	'	'
Weighted average remaining amortization period (in years)	'4 years	'	'	'	'	'	'2 years	'5 years	'5 years
Amortization expense related to intangible assets	$100,000	$100,000	'	'	'	$100,000	'	'	'

Recovered_Sheet2

Goodwill and Other Intangible Assets - Carrying Amount and Accumulated Amortization of Intangible Assets (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, unless otherwise specified
Goodwill And Other Intangible Assets [Line Items]	'	'
Carrying Amount	$2,038	$2,038
Accumulated Amortization	1,725	1,571
Patents [Member]	'	'
Goodwill And Other Intangible Assets [Line Items]	'	'
Carrying Amount	1,748	1,748
Accumulated Amortization	1,538	1,500
Customer Lists [Member]	'	'
Goodwill And Other Intangible Assets [Line Items]	'	'
Carrying Amount	190	190
Accumulated Amortization	154	59
Non-Compete Agreements [Member]	'	'
Goodwill And Other Intangible Assets [Line Items]	'	'
Carrying Amount	100	100
Accumulated Amortization	$33	$12

Preferred_Stock_Subject_to_Man1

Preferred Stock Subject to Mandatory Redemption - Additional Information (Detail) (USD $)	12 Months Ended		3 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended
	Aug. 31, 2012	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2012	Aug. 31, 2012	Apr. 07, 2010	Aug. 31, 2012	Apr. 07, 2010
			Series A Preferred Stock [Member]	Series A Preferred Stock [Member]	Series B Preferred Stock [Member]	Series A Cumulative Non-Voting Non-Convertible Preferred Stock, Redeemable [Member]	Series A Cumulative Non-Voting Non-Convertible Preferred Stock, Redeemable [Member]	Series B Voting Convertible Preferred Stock [Member]
Class of Stock [Line Items]	'	'	'	'	'	'	'	'
Preferred stock issued value	'	'	'	'	'	$40,000,000	'	$7,700,000
Dividend on preferred stock (in percentage)	'	'	'	'	'	15.00%	6.00%	'
Preferred stock, shares issued (in shares)	'	0	'	'	'	'	'	100,000
Preferred Stock, shares authorized (in shares)	'	1,000,000	'	'	'	'	'	'
Preferred stock, shares par value (in USD per share)	'	$1	'	'	'	'	'	'
Preferred stock, shares outstanding (in shares)	'	0	'	'	'	'	'	'
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Fair Value of Shares	'	'	'	'	'	32,300,000	'	'
Amortization period of the discount on the Series A mandatory redeemable preferred stock (in years)	'	'	'	'	'	'	'7 years	'
Preferred stock dividends accrued as a percentage of outstanding Preferred Stock	'	'	'	'	'	'	9.00%	'
Preferred stock, redeemed	40,000,000	'	'	48,900,000	'	'	'	'
Preferred stock, redeemed shares	'	'	'	100,000	'	'	'	'
Preferred stock redemption price	'	'	23,500,000	40,000,000	'	'	'	'
Accrued dividend	'	'	5,400,000	8,900,000	'	'	'	'
Accelerated discount accretion	'	'	3,200,000	5,500,000	'	'	'	'
Amortization of issuance costs	'	'	'	$1,100,000	'	'	'	'
Preferred stock, converted	'	'	'	'	100,000	'	'	'
Common stock, Converted shares	'	'	'	'	1,000,000	'	'	'

Debt_Longterm_Debt_and_Capital

Debt - Long-term Debt and Capital Lease Obligations Current and Non Current (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Capital lease obligations	$231	$423
Debt and capital lease obligations, including current portion and short-term borrowings	72,970	84,462
Less: current portion and short-term borrowings	231	458
Long-term debt and capital lease obligations	72,739	84,004
Secured Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Carrying amount of debt	71,506	82,606
Iowa Department of Economic Development Loans [Member]	'	'
Debt Instrument [Line Items]	'	'
Carrying amount of debt	$1,233	$1,433

Debt_Longterm_Debt_and_Capital1

Debt - Long-term Debt and Capital Lease Obligations Current and Non Current (Parenthetical) (Detail) (Secured Debt [Member])	Aug. 31, 2013
Secured Debt [Member]	'
Debt Instrument [Line Items]	'
Secured credit agreements - weighted average interest rate (in percentage)	3.18%

Debt_Additional_Information_De

Debt - Additional Information (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2013	Jul. 31, 2012	Aug. 31, 2013	Aug. 31, 2013	Aug. 31, 2013	Aug. 31, 2013	Aug. 31, 2013
			Maximum [Member]	2012 Agreement [Member]	2012 Agreement [Member]	2012 Agreement [Member]	2012 Agreement [Member]	2012 Agreement [Member]	2012 Agreement [Member]
						Two Consecutive Quarters [Member]	Minimum [Member]	Maximum [Member]	Maximum [Member]
									Scenario, Forecast [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'	'
Maximum borrowing amount under amended and restated credit agreement	'	'	'	$130,000,000	'	'	'	'	'
Scheduled principal payment	'	'	'	0	'	'	'	'	'
Debt instrument maturity date	'	'	'	9-Jul-17	'	'	'	'	'
Line of credit, amount outstanding	'	'	'	'	71,500,000	'	'	'	'
Debt Instrument, Description of Variable Rate Basis over LIBOR (in percentage)	'	'	'	'	'	'	2.00%	4.00%	'
Covenant, maximum total leverage ratio permitted through November 30, 2013	'	'	'	'	'	2	'	'	3.5
Covenant, maximum total leverage ratio permitted from December 1, 2013 through May 31, 2014	'	'	'	'	'	'	'	'	3.25
Covenant, maximum total leverage ratio permitted after May 31, 2014	'	'	'	'	'	'	'	3	'
Covenant, fixed coverage ratio	'	'	'	'	'	'	1.35	'	'
Covenant, amount of annual capital expenditures permitted	'	'	'	'	'	'	'	15,000,000	'
Covenant, dividend declaration permitted	'	'	'	'	'	'	'	10,000,000	'
Dividend declared, Percentage of cash flow	'	'	'	'	50.00%	'	'	'	'
Capital lease obligations	231,000	423,000	'	'	'	'	'	'	'
Current portion of capital leases	'	'	$100,000	'	'	'	'	'	'

Debt_Iowa_Department_of_Econom

Debt - Iowa Department of Economic Development - Additional Information (Detail) (Iowa Department of Economic Development Loans [Member], USD $)	3 Months Ended	12 Months Ended
	Nov. 30, 2009	Aug. 31, 2013	Aug. 31, 2012
		SecurityLoan
Iowa Department of Economic Development Loans [Member]	'	'	'
Debt Instrument [Line Items]	'	'	'
Number of non interest bearing loans	'	2	'
Loan period (in years)	'	'5 years	'
Non interest bearing loans	$1,000,000	'	'
Number of monthly payments	'60 equal monthly payments	'	'
Potentially forgivable loan amount	'	1,000,000	'
Periodic repayments of loan	16,667	'	'
Outstanding amount of IDED loans	'	$1,233,000	$1,433,000

Debt_Schedule_of_Maturities_of

Debt - Schedule of Maturities of Long-term Debt (Detail) (USD $)	Aug. 31, 2013
In Thousands, unless otherwise specified
Debt Disclosure [Abstract]	'
2014	$231
2015	1,103
2016	57
2017	71,554
2018	25
Total	$72,970

Stockholders_Equity_Common_Sha

Stockholders' Equity - Common Shares Outstanding (Detail)	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Statement Of Stockholders Equity [Abstract]	'	'	'
Balance, beginning of year	14,280,718	13,243,385	13,189,581
Series B preferred stock converted to common shares	'	1,000,000	'
Exercise of stock options	121,226	'	'
Issuance of restricted stock, net	52,237	37,333	53,804
Balance, end of year	14,454,181	14,280,718	13,243,385

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail)	12 Months Ended
	Aug. 31, 2012
Series B Voting Convertible Preferred Stock [Member]	'
Conversion of Stock [Line Items]	'
Series B preferred stock	100,000
Common Stock [Member]	'
Conversion of Stock [Line Items]	'
Series B preferred stock converted to common shares	1,000,000

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Income (Loss) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'
Beginning Balance	($15,593)	($7,559)	($13,850)
Other comprehensive income (loss), net of taxes	7,974	-8,034	6,291
Ending Balance	-7,619	-15,593	-7,559
Net Unrealized Gains (Losses) on Cash Flow Hedging Instruments [Member]	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'
Beginning Balance	1,638	731	-582
Other comprehensive income (loss), net of taxes	-2,494	907	1,313
Ending Balance	-856	1,638	731
Gains (Losses) on Postretirement Obligations [Member]	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'
Beginning Balance	-17,231	-8,290	-13,268
Other comprehensive income (loss), net of taxes	10,468	-8,941	4,978
Ending Balance	($6,763)	($17,231)	($8,290)

Leases_Additional_Information_

Leases - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Operating Leased Assets [Line Items]	'	'	'
Rental expense under operating leases, net	$6.30	$6	$5.40
Minimum [Member] | Vehicles and Office Equipment [Member]	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Operating lease term (in years)	'1 year	'	'
Minimum [Member] | Real Estate Leases [Member]	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Operating lease term (in years)	'5 years	'	'
Maximum [Member] | Vehicles and Office Equipment [Member]	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Operating lease term (in years)	'15 years	'	'
Maximum [Member] | Real Estate Leases [Member]	'	'	'
Operating Leased Assets [Line Items]	'	'	'
Operating lease term (in years)	'20 years	'	'

Leases_Future_Minimum_Lease_Pa

Leases - Future Minimum Lease Payments for Noncancelable Operating and Capital Leases (Detail) (USD $)	Aug. 31, 2013
In Thousands, unless otherwise specified
Leases [Abstract]	'
2014	$70
2015	69
2016	67
2017	52
2018	17
Thereafter	9
Total minimum lease payments	284
Less: amounts representing interest	-53
Net minimum lease payments, Capital Leases	231
2014	2,836
2015	1,701
2016	942
2017	448
2018	41
Thereafter	'
Total minimum lease payments, Operating Leases	$5,968

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

Aug. 31, 2013

Jan. 11, 2012

Jan. 26, 2012

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2012

Aug. 31, 2011

Aug. 31, 2013

Jan. 01, 2013

Jan. 26, 2012

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2012

Aug. 31, 2011

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2011

Aug. 31, 2011

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2013

Carolina Starches, LLC [Member]

2006 Incentive Plan [Member]

2006 Incentive Plan [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Restricted Stock [Member]

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

Non Qualified Stock Options And Restricted Stock [Member]

Non Qualified Stock Options And Restricted Stock [Member]

Non Qualified Stock Options And Restricted Stock [Member]

Maximum [Member]

2006 Incentive Plan [Member]

2006 Incentive Plan [Member]

2006 Incentive Plan [Member]

2006 Incentive Plan [Member]

2006 Incentive Plan [Member]

2006 Incentive Plan [Member]

2006 Incentive Plan [Member]

2006 Incentive Plan [Member]

2006 Incentive Plan [Member]

2006 Incentive Plan [Member]

2006 Incentive Plan [Member]

2006 Incentive Plan [Member]

Non Employee Directors [Member]

Non Employee Directors [Member]

Vesting Period Two Years [Member]

Vesting Period Three Years [Member]

Vesting Period One Year [Member]

Vesting Period Four Years [Member]

Minimum [Member]

Maximum [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of additional common shares authorized for issuance under the plan (in shares)

'

'

800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of common shares available for issuance under the plan

'

'

'

388,882

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vesting period (in Years)

'

'2 years

'

'

'

'

'

'

'1 year

'1 year

'

'

'3 years

'

'2 years

'3 years

'1 year

'4 years

'

'1 year

'4 years

Expiration period (in years)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'Seven years

'

'

Share price of Company's stock

$13.55

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Intrinsic value of options exercised

$835,300

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options granted during the period

'

82,500

'

'

'

'

'

'

'

'

'

120,000

678,000

98,000

75,000

45,000

80,000

18,000

'

'

'

Option term

'

'7 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Compensation expense related to non-vested awards not yet recognized

'

'

'

'

'

'

'

'

'

'

900,000

'

'

'

'

'

'

'

'

'

'

Weighted-average period over which unrecognized compensation cost will be recognized (in years)

'

'

'

'

'3 months 18 days

'

'

'

'

'

'1 year 2 months 12 days

'

'

'

'

'

'

'

'

'

'

Total fair value of restricted stock vested

'

'

'

'

400,000

1,000,000

1,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares issued for non-employee director, shares

'

'

'

'

'

'

'

'

2,721

3,539

'

'

'

'

'

'

'

'

'

'

'

Restricted stock awards granted

'

'

'

'

24,489

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Compensation expense related to unvested awards not yet recognized

'

'

'

'

'

'

'

$100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

StockBased_Compensation_Schedu

Stock-Based Compensation - Schedule of Share Based Compensation Stock Options Activity (Detail) (USD $)

12 Months Ended

12 Months Ended

12 Months Ended

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2012

Aug. 31, 2012

Aug. 31, 2012

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2013

Aug. 31, 2013

Minimum [Member]

Maximum [Member]

Outstanding Beginning Balance Option Price Range [Member]

Outstanding Beginning Balance Option Price Range [Member]

Outstanding Beginning Balance Option Price Range [Member]

Granted During Period Option Price Range [Member]

Granted During Period Option Price Range [Member]

Granted During Period Option Price Range [Member]

Cancelled During Period Option Price Range [Member]

Cancelled During Period Option Price Range [Member]

Cancelled During Period Option Price Range [Member]

Outstanding Ending Balance Option Price Range [Member]

Outstanding Ending Balance Option Price Range [Member]

Outstanding Ending Balance Option Price Range [Member]

Exercisable Ending Balance Option Price Range [Member]

Exercisable Ending Balance Option Price Range [Member]

Exercisable Ending Balance Option Price Range [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options outstanding, beginning of period, Shares

'

'

'

1,824,916

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options outstanding, end of period, Shares

'

'

'

1,824,916

'

'

'

'

'

'

'

'

1,517,588

'

'

'

'

'

Shares, Granted

'

'

'

'

'

'

120,000

'

'

'

'

'

'

'

'

'

'

'

Option Price Range, Outstanding end of the period

'

'

'

$10.94

$4.66

$21.73

'

'

'

'

'

'

$10.30

$4.66

$21.73

'

'

'

Shares, Exercised

-222,864

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares, Cancelled

'

'

'

'

'

'

'

'

'

-204,464

'

'

'

'

'

'

'

'

Options exercisable, end of period, Shares

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

895,339

'

'

Option Price Range, Outstanding Beginning of the period

'

'

'

$10.94

$4.66

$21.73

'

'

'

'

'

'

'

$4.66

$21.73

'

'

'

Option Price Range, Granted

'

'

'

'

'

'

$8.49

$7.60

$11.09

'

'

'

'

'

'

'

'

'

Option Price Range, Exercised

$10.31

$5.29

$12.79

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Option Price Range, Cancelled

'

'

'

'

'

'

'

'

'

$14.99

$9.87

$17.07

'

'

'

'

'

'

Options Price Range, Exercisable end of period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$13.17

$4.66

$21.73

Weighted Average Remaining Term, Outstanding, Ending Balance (in years)

'

'

'

'

'

'

'

'

'

'

'

'

'3 years 10 months 24 days

'

'

'

'

'

Weighted Average Remaining Term, Options Exercisable (in years)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'2 years 8 months 27 days

'

'

Aggregate Intrinsic value, Outstanding, Ending Balance

'

'

'

'

'

'

'

'

'

'

'

'

$6,737,300

'

'

'

'

'

Aggregate Intrinsic value, Options Exercisable

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$2,144,000

'

'

StockBased_Compensation_Schedu1

Stock-Based Compensation - Schedule of Share Based Payment Award Stock Options Valuation Assumptions (Detail) (Stock Options [Member], USD $)	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Stock Options [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Expected volatility	68.00%	68.00%	71.00%
Expected life (years)	'4 years 8 months 12 days	'4 years 10 months 24 days	'4 years 3 months 18 days
Interest rate, minimum	0.50%	0.50%	1.10%
Interest rate, maximum	1.00%	1.10%	2.80%
Dividend yield	0.00%	0.00%	0.00%
Weighted-average fair values	$4.60	$3.13	$3.62

StockBased_Compensation_Schedu2

Stock-Based Compensation - Schedule of Share-Based Compensation, Restricted Stock Award Activity (Detail) (Restricted Stock [Member], USD $)	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2011
Restricted Stock [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Shares, Nonvested at August 31, 2012	61,716	'
Shares, Granted	24,489	0
Shares, Vested	-61,716	'
Shares, Cancelled	'	'
Shares, Nonvested at August 31, 2013	24,489	'
Weighted-Average Grant-Date Fair Value, Beginning balance (in USD per share)	$5.94	'
Weighted-Average Grant-Date Fair Value, Granted (in USD per share)	$7.35	'
Weighted-Average Grant-Date Fair Value, Vested (in USD per share)	$5.94	'
Weighted-Average Grant-Date Fair Value, Cancelled (in USD per share)	'	'
Weighted-Average Grant-Date Fair Value, Ending balance (in USD per share)	$7.35	'

StockBased_Compensation_Schedu3

Stock-Based Compensation - Schedule of Employee Service Share-Based Compensation, Allocation of Recognized Period Costs (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Total stock-based compensation expense	$1,404	$1,387	$1,117
Income tax benefit	-534	-527	-424
Total stock-based compensation expense, net of tax	870	860	693
Cost of Sales [Member]	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Total stock-based compensation expense	'	48	130
Operating Expense [Member]	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Total stock-based compensation expense	1,404	1,324	949
Research and Development Expense [Member]	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'
Total stock-based compensation expense	'	$15	$38

Pensions_and_Other_Postretirem2

Pensions and Other Postretirement Benefits - Additional Information (Detail) (USD $)	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
	Contracts
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Number of defined benefit plans	2	'	'
Employees covered under noncontributory defined benefit pension plans (in percentage)	56.00%	'	'
Redemption requests notice period (in days)	'110 days	'	'
Employer contributions	$1,100,000	$4,100,000	$6,400,000
Minimum pension plan funding contribution during fiscal 2014	2,500,000	'	'
Pension Benefits [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Expected long-term return on assets assumption used to calculate net periodic pension expense (in percentage)	7.00%	8.00%	8.00%
Hypothetical decrease in the expected return on assets assumption, to determine impact on expense (in percentage)	0.50%	'	'
Estimated increase in expense resulting from a hypothetical decrease of 50 bps in the expected return on plan assets assumption	200,000	'	'
Discount rate (in percentage)	4.28%	5.87%	5.64%
Discount rate (in percentage)	5.24%	4.28%	5.87%
Hypothetical decrease in the discount rate assumption, to determine impact on expense (in percentage)	0.25%	'	'
Estimated increase in expense resulting from a hypothetical decrease of 25 bps in the discount rate assumption	240,000	'	'
Employer contributions	1,136,000	4,052,000	'
Pension Benefits [Member] | Penford Corporation [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Plan assets invested	0	'	'
Pension Benefits [Member] | Scenario, Forecast [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Expected long-term return on assets assumption used to calculate net periodic pension expense (in percentage)	7.00%	'	'
Discount rate (in percentage)	5.24%	'	'
Defined Benefit Plan, Amortization of Net Gains (Losses), next fiscal year	500,000	'	'
Other Benefits [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Discount rate (in percentage)	4.28%	5.87%	5.64%
Discount rate (in percentage)	5.24%	4.28%	5.87%
Hypothetical decrease in the discount rate assumption, to determine impact on expense (in percentage)	0.25%	'	'
Plan assets invested	0	'	'
Employer contributions	$551,000	$522,000	'

Pensions_and_Other_Postretirem3

Pensions and Other Postretirement Benefits - Summary of Pension and Other Postretirement Benefit Plans (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Change in plan assets:	'	'	'
Company contributions	$1,100	$4,100	$6,400
Balance, August 31, 2013	46,726	'	'
Pension Benefits [Member]	'	'	'
Change in benefit obligation:	'	'	'
Benefit obligation, beginning balance	62,989	47,545	'
Service cost	1,945	1,521	1,617
Interest cost	2,648	2,729	2,696
Amendments	'	212	'
Actuarial (gain) loss	-107	619	'
Change in assumptions	-8,135	12,359	'
Benefits paid	-2,062	-1,996	'
Benefit obligation, ending balance	57,278	62,989	47,545
Change in plan assets:	'	'	'
Balance, August 31, 2012	42,072	36,328	'
Actual return on plan assets	5,580	3,688	'
Company contributions	1,136	4,052	'
Benefits paid	-2,062	-1,996	'
Balance, August 31, 2013	46,726	42,072	36,328
Funded status:	'	'	'
Net liability - Plan assets less than projected benefit obligation	-10,552	-20,917	'
Recognized as:	'	'	'
Non-current accrued benefit liability	-10,552	-20,917	'
Net Amount Recognized	-10,552	-20,917	'
Other Benefits [Member]	'	'	'
Change in benefit obligation:	'	'	'
Benefit obligation, beginning balance	20,457	16,924	'
Service cost	235	229	272
Interest cost	860	972	972
Plan participants' contributions	106	119	'
Actuarial (gain) loss	267	-170	'
Change in assumptions	-3,912	3,024	'
Benefits paid	-657	-641	'
Benefit obligation, ending balance	17,356	20,457	16,924
Change in plan assets:	'	'	'
Company contributions	551	522	'
Plan participants' contributions	106	119	'
Benefits paid	-657	-641	'
Funded status:	'	'	'
Net liability - Plan assets less than projected benefit obligation	-17,356	-20,457	'
Recognized as:	'	'	'
Current accrued benefit liability	-760	-750	'
Non-current accrued benefit liability	-16,596	-19,707	'
Net Amount Recognized	($17,356)	($20,457)	'

Pensions_and_Other_Postretirem4

Pensions and Other Postretirement Benefits - Components of Accumulated Other Comprehensive Loss Unrecognized (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, unless otherwise specified
Pension Benefits [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Unrecognized prior service cost (credit)	$1,288	$1,529
Unrecognized net actuarial loss	10,091	22,976
Total	11,379	24,505
Other Benefits [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Unrecognized prior service cost (credit)	-155	-307
Unrecognized net actuarial loss	-318	3,594
Total	($473)	$3,287

Pensions_and_Other_Postretirem5

Pensions and Other Postretirement Benefits - Benefit Obligations in Excess of Fair Value of Plan Assets (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, unless otherwise specified
Compensation And Retirement Disclosure [Abstract]	'	'
Projected benefit obligation	$57,278	$62,989
Accumulated benefit obligation	54,389	59,853
Fair value of plan assets	$46,726	$42,072

Pensions_and_Other_Postretirem6

Pensions and Other Postretirement Benefits - Components of Net Periodic Benefit Cost (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Pension Benefits [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost	$1,945	$1,521	$1,617
Interest cost	2,648	2,729	2,696
Expected return on plan assets	-2,869	-2,914	-2,234
Amortization of prior service cost	241	228	228
Amortization of actuarial loss	1,932	773	1,441
Benefit cost	3,897	2,337	3,748
Other Benefits [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost	235	229	272
Interest cost	860	972	972
Amortization of prior service cost	-152	-152	-152
Amortization of actuarial loss	267	'	65
Benefit cost	$1,210	$1,049	$1,157

Pensions_and_Other_Postretirem7

Pensions and Other Postretirement Benefits - Benefit Plan Assumptions (Detail)	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Pension Benefits [Member]	'	'	'
Weighted-average assumptions used to calculate net periodic expense:	'	'	'
Discount rate	4.28%	5.87%	5.64%
Expected return on plan assets	7.00%	8.00%	8.00%
Rate of compensation increase	3.00%	3.00%	4.00%
Weighted-average assumptions used to calculate benefit obligations at August 31:	'	'	'
Discount rate	5.24%	4.28%	5.87%
Expected return on plan assets	7.00%	7.00%	8.00%
Rate of compensation increase	3.00%	3.00%	3.00%
Other Benefits [Member]	'	'	'
Weighted-average assumptions used to calculate net periodic expense:	'	'	'
Discount rate	4.28%	5.87%	5.64%
Weighted-average assumptions used to calculate benefit obligations at August 31:	'	'	'
Discount rate	5.24%	4.28%	5.87%

Pensions_and_Other_Postretirem8

Pensions and Other Postretirement Benefits - Assumed Health Care Cost Trend Rates (Detail)	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Compensation And Retirement Disclosure [Abstract]	'	'	'
Current health care trend assumption	7.80%	8.00%	8.00%
Ultimate health care trend rate	4.50%	4.50%	4.50%
Year ultimate health care trend is reached	'2032	'2030	'2029

Pensions_and_Other_Postretirem9

Pensions and Other Postretirement Benefits - Effect of Changes in Assumed Health Care Cost Trend Rate (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013
Compensation And Retirement Disclosure [Abstract]	'
Effect on total of service and interest cost components in fiscal 2013, one percentage point increase in health care trend rate	$182
Effect on postretirement accumulated benefit obligation as of August 31, 2013, one percentage point increase in health care trend rate	2,405
Effect on total of service and interest cost components in fiscal 2013, one percentage point decrease in health care trend rate	-146
Effect on postretirement accumulated benefit obligation as of August 31, 2013, one percentage point decrease in health care trend rate	($1,999)

Recovered_Sheet3

Pensions and Other Postretirement Benefits - Weighted Average Asset Allocations of Investment Portfolio for Pension Plans (Detail)	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012
U.S. Equities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Target asset allocation	55.00%	'
Weighted average asset allocation	55.00%	56.00%
International Equities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Target asset allocation	15.00%	'
Weighted average asset allocation	15.00%	15.00%
Fixed Income Investments [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Target asset allocation	25.00%	'
Weighted average asset allocation	25.00%	24.00%
Real Estate [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Target asset allocation	5.00%	'
Weighted average asset allocation	5.00%	5.00%

Recovered_Sheet4

Pensions and Other Postretirement Benefits - Fair Value of Pension Plan's Assets by Major Asset Category (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets	$46,726	$42,072
Fair value of plan assets	46,726	'
Common collective trust funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets	44,378	'
Real estate equity funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets	2,348	'
Fair value of plan assets	2,348	2,102
Level 1 [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets	'	'
Level 1 [Member] | Common collective trust funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets	'	'
Level 1 [Member] | Real estate equity funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets	'	'
Level 2 [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets	44,378	'
Level 2 [Member] | Common collective trust funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets	44,378	'
Level 3 [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets	2,348	'
Level 3 [Member] | Real estate equity funds [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Fair value of plan assets	$2,348	'

Recovered_Sheet5

Pensions and Other Postretirement Benefits - Changes in Fair Value of Pension Plan's Real Estate Equity Fund (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013
Actual return on plan assets:	'
Balance, August 31, 2013	$46,726
Real estate equity funds [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Balance, August 31, 2012	2,102
Actual return on plan assets:	'
Relating to assets still held at the reporting date	246
Relating to assets sold during the period	'
Purchases and sales	'
Transfers in (out) of Level 3	'
Balance, August 31, 2013	$2,348

Recovered_Sheet6

Pensions and Other Postretirement Benefits - Expected Benefit Payments (Detail) (USD $)	Aug. 31, 2013
In Millions, unless otherwise specified
Pension Benefits [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
2014	$2.40
2015	2.5
2016	2.6
2017	2.8
2018	3
2019-2023	18.7
Other Benefits [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
2014	0.9
2015	1
2016	1
2017	1.1
2018	1.2
2019-2023	$7.70

Other_Employee_Benefits_Additi

Other Employee Benefits - Additional Information (Detail) (USD $)	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Savings and Stock Ownership Plan [Member]	'	'	'
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]	'	'	'
Deferral maximum salary percentage	16.00%	'	'
Employer's match of the first 0% of an employee's salary contributed by that employee to the plan	100.00%	'	'
Percentage of salary under first plan	3.00%	'	'
Employer's match of the second 0% of an employee's salary contributed by that employee to the plan	50.00%	'	'
Company's matching contributions	$1,200,000	$1,000,000	$900,000
Postretirement Health Care and Life Insurance Benefits [Member]	'	'	'
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]	'	'	'
Pension and postretirement benefits expense, deferred compensation arrangement	5,900,000	5,100,000	4,500,000
Deferred Compensation Plan [Member]	'	'	'
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]	'	'	'
Pension and postretirement benefits expense, deferred compensation arrangement	177,000	179,000	197,000
Supplemental Executive Retirement Plans [Member]	'	'	'
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]	'	'	'
Pension and postretirement benefits expense, deferred compensation arrangement	271,000	258,000	370,000
Accrued pension plan obligation	$2,700,000	'	'

Fair_Value_Measurements_and_De2

Fair Value Measurements and Derivative Instruments - Fair Values of Company's Derivative Instruments (Detail) (Other Current Assets [Member], Commodity Contract [Member], USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, unless otherwise specified
Derivative [Line Items]	'	'
Commodity derivatives	$512	($1,422)
Level 1 [Member]	'	'
Derivative [Line Items]	'	'
Commodity derivatives	512	-1,422
Level 2 [Member]	'	'
Derivative [Line Items]	'	'
Commodity derivatives	'	'
Level 3 [Member]	'	'
Derivative [Line Items]	'	'
Commodity derivatives	'	'

Fair_Value_Measurements_and_De3

Fair Value Measurements and Derivative Instruments - Fair Values of Company's Derivative Instruments (Parenthetical) (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Millions, unless otherwise specified
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'	'
Cash collateral due offset	$1.70	$2.60

Fair_Value_Measurements_and_De4

Fair Value Measurements and Derivative Instruments - Additional Information (Detail) (USD $)	12 Months Ended
	Aug. 31, 2011	Aug. 31, 2013	Aug. 31, 2013	Aug. 31, 2013	Aug. 31, 2013	Aug. 31, 2013	Aug. 31, 2012
		Commodity Contract [Member]	Commodity Contract [Member]	Commodity Contract [Member]	Commodity Contract [Member]	Iowa Department of Economic Development Loans [Member]	Iowa Department of Economic Development Loans [Member]
			Designated as Hedging Instrument [Member]	Firm Priced Starch and Ethanol Futures [Member]	Open Position [Member]
			Corn Futures [Member]	Designated as Hedging Instrument [Member]	Designated as Hedging Instrument [Member]
			bu	Corn Futures [Member]	Corn Futures [Member]
				bu	bu
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'	'	'	'	'	'
Carrying value of debt	'	'	'	'	'	$1,233,000	$1,433,000
Fair value of debt	'	'	'	'	'	1,200,000	'
Pretax losses continued to be deferred in accumulated other comprehensive income	500,000	'	'	'	'	'	'
Deferred loss, net of tax, recorded in other comprehensive income	'	($900,000)	'	'	'	'	'
Purchased corn positions	'	'	3,100,000	2,200,000	900,000	'	'

Fair_Value_Measurements_and_De5

Fair Value Measurements and Derivative Instruments - Outstanding Futures Contracts (Detail) (Designated as Hedging Instrument [Member], Commodity Contract [Member])	Aug. 31, 2013
	bu
Corn Futures [Member]	'
Derivative [Line Items]	'
Outstanding futures contracts	4,190,000
Ethanol Swaps [Member]	'
Derivative [Line Items]	'
Outstanding futures contracts	7,350,000

Fair_Value_Measurements_and_De6

Fair Value Measurements and Derivative Instruments - Effect of Derivative Instruments on Company's Financial Performance (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Cash Flow Hedges [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Gain (Loss) Recognized in AOCI	$1,204	$3,734	($9,708)
Amount of Gain (Loss) Reclassified from AOCI into Income	5,228	2,271	-11,825
Amount of Gain (Loss) Recognized in Income	-1,021	36	-247
Cash Flow Hedges [Member] | Corn Futures [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Gain (Loss) Recognized in AOCI	-407	2,067	-4,949
Amount of Gain (Loss) Reclassified from AOCI into Income	5,351	1,500	-7,418
Amount of Gain (Loss) Recognized in Income	-870	36	-162
Cash Flow Hedges [Member] | Natural Gas Futures [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Gain (Loss) Recognized in AOCI	'	'	-579
Amount of Gain (Loss) Reclassified from AOCI into Income	'	-492	-1,332
Amount of Gain (Loss) Recognized in Income	'	'	-85
Cash Flow Hedges [Member] | Ethanol Futures [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Gain (Loss) Recognized in AOCI	1,611	1,667	-4,180
Amount of Gain (Loss) Reclassified from AOCI into Income	-123	1,263	-3,075
Amount of Gain (Loss) Recognized in Income	-151	'	'
Fair Value Hedges [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Gain (Loss) Recognized in Income	94	-1,078	'
Fair Value Hedges [Member] | FX Contracts [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Gain (Loss) Recognized in Income	'	6	'
Fair Value Hedges [Member] | Soybean Oil Futures [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Gain (Loss) Recognized in Income	'	12	'
Fair Value Hedges [Member] | Soybean Meal Futures [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Gain (Loss) Recognized in Income	'	-14	'
Fair Value Hedges [Member] | Corn Futures [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Gain (Loss) Recognized in Income	363	98	28
Fair Value Hedges [Member] | Natural Gas Futures [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Amount of Gain (Loss) Recognized in Income	$94	($1,082)	'

Recovered_Sheet7

Other Non-Operating Income (Expense) - Other Non-Operating Income (Expense) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Component of Other Expense, Nonoperating [Abstract]	'	'	'
Other non-operating income (expense)	$75	($6,186)	$115
Series A Preferred Stock [Member]	'	'	'
Component of Other Expense, Nonoperating [Abstract]	'	'	'
Other non-operating income (expense)	'	-6,599	'
Other [Member]	'	'	'
Component of Other Expense, Nonoperating [Abstract]	'	'	'
Other non-operating income (expense)	$75	$413	$115

Recovered_Sheet8

Other Non-Operating Income (Expense) - Additional Information (Detail) (Series A Preferred Stock [Member], USD $)	3 Months Ended	12 Months Ended
In Millions, except Share data, unless otherwise specified	Aug. 31, 2012	Aug. 31, 2012
Series A Preferred Stock [Member]	'	'
Component Of Other Income Expense Nonoperating [Line Items]	'	'
Redeemed shares	'	100,000
Original issue price of redeemed shares	$23.50	$40
Accrued dividend of redeemed shares	5.4	8.9
Accelerated discount accretion	3.2	5.5
Amortization of issuance cost	'	$1.10

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Income Taxes [Line Items]	'	'	'
U.S. income (loss) before income taxes	$5,000,000	($4,900,000)	($4,200,000)
Foreign income (loss) before income taxes	500,000	100,000	-600,000
Foreign tax expense	0	0	0
Valuation allowance	12,537,000	12,797,000	'
Net deferred tax assets	6,466,000	13,275,000	'
Total amount of gross unrecognized tax benefits, if recognized that would impact effective tax rate	700,000	'	'
Accrued interest and penalties included in long-term tax liability	100,000	200,000	'
Liability decreased relating to unrecognized tax benefits, interest	44,000	'	'
Liability decreased relating to unrecognized tax benefits, penalties	51,000	'	'
Domestic Tax Authority [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Operating Loss Carryforwards	10,800,000	'	'
Net operating loss carryforward, expiration year	'2030	'	'
State and Local Jurisdiction [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Research and development credit carryforward expiration period	'2014	'	'
Research and development credit carryforward expiration period	'2030	'	'
Operating Loss Carryforwards	19,800,000	'	'
Australia and New Zealand Discontinued Operations [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Valuation allowance	10,900,000	'	'
Deferred tax benefit, net	10,900,000	'	'
Federal Alternative Minimum [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Tax Credit Carryforward Amount	3,500,000	'	'
Research and Development [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Tax Credit Carryforward Amount	1,700,000	'	'
Research and development credit carryforward expiration period	'2025	'	'
Research and development credit carryforward expiration period	'2032	'	'
Small Ethanol Producer [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Tax Credit Carryforward Amount	2,600,000	'	'
Tax credit carryforward, expiration year	'2014	'	'
Valuation allowance	'	1,800,000	'
Valuation allowance, amount reduced	100,000	'	'
Charitable Contributions [Member]	'	'	'
Income Taxes [Line Items]	'	'	'
Research and development credit carryforward expiration period	'2013	'	'
Research and development credit carryforward expiration period	'2015	'	'
Valuation allowance	'	44,000	'
Valuation allowance, amount reduced	$22,000	'	'
Charitable contribution deduction limitation as a percentage of taxable income	10.00%	'	'
Carry forward period allowed	'5 years	'	'

Income_Taxes_Schedule_of_US_In

Income Taxes - Schedule of U.S. Income Tax Expense (Benefit) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Current:	'	'	'
Federal	($422)	($162)	$34
State	80	3	137
Current Income Tax Expense (Benefit), Total	-342	-159	171
Deferred:	'	'	'
Federal	1,829	4,582	9
State	-4	383	133
Deferred income tax expense (benefit)	1,825	4,965	142
Total	$1,483	$4,806	$313

Income_Taxes_Schedule_of_Alloc

Income Taxes - Schedule of Allocable Comprehensive Tax Expense (Benefit) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Income before taxes	$1,483	$4,806	$313
Comprehensive income (loss)	4,887	-4,924	3,856
Comprehensive tax expense (benefit)	$6,370	($118)	$4,169

Income_Taxes_Reconciliation_of

Income Taxes - Reconciliation of Statutory Federal Tax to Actual Provision (Benefit) for Taxes (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Statutory tax rate	35.00%	35.00%	35.00%
Statutory tax on income	$1,921	($1,666)	($1,682)
State taxes, net of federal benefit	94	219	52
Non-deductible expenses related to preferred stock	'	4,547	2,687
Research credit	-189	-73	-195
Ethanol credit	'	'	-975
Foreign taxes	-183	-38	200
Stock option exercises/expirations	376	'	'
Prior year true up	-265	95	79
Unrecognized tax benefits	-359	-165	67
Valuation allowance	-104	1,787	'
Other	192	100	80
Total	$1,483	$4,806	$313

Income_Taxes_Schedule_of_Signi

Income Taxes - Schedule of Significant Components of Deferred Tax Assets and Liabilities (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, unless otherwise specified
Deferred tax assets:	'	'
Alternative minimum tax credit	$3,473	$3,354
Postretirement benefits	11,920	18,060
Provisions for accrued expenses	2,791	2,908
Stock-based compensation	2,453	2,420
Net operating loss carryforward	4,575	7,469
Tax credit carryforwards	4,373	4,152
NOL carryforward-foreign	10,853	11,010
Hedging	525	'
Other	2,092	2,025
Total deferred tax assets gross	43,055	51,398
Less - valuation allowance	-12,537	-12,797
Total deferred tax assets	30,518	38,601
Deferred tax liabilities:	'	'
Depreciation	22,296	21,762
Hedging	'	1,004
Other	1,756	2,560
Total deferred tax liabilities	24,052	25,326
Net deferred tax assets	6,466	13,275
Recognized as:	'	'
Other current assets	1,479	167
Deferred tax asset	4,987	13,108
Total net deferred tax assets	$6,466	$13,275

Income_Taxes_Reconciliation_of1

Income Taxes - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012
Income Tax Disclosure [Abstract]	'	'
Unrecognized tax benefits at beginning of year	$1,058	$1,220
Additions for tax positions related to prior years	134	112
Additions for tax positions related to current year	90	62
Reductions due to lapse of applicable statute of limitations	-576	-336
Unrecognized tax benefits at end of year	$706	$1,058

Recovered_Sheet9

Earnings (Loss) Per Common Share - Reconciliation of Income from Operations Applicable to Common Shares and Computation of Diluted Weighted Average Shares Outstanding (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Aug. 31, 2013	31-May-13	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	31-May-12	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Numerator:	'	'	'	'	'	'	'	'	'	'	'
Net income (loss)	($949)	$2,058	$1,191	$1,707	($4,366)	($5,452)	($340)	$592	$4,007	($9,566)	($5,117)
Less: Allocation to participating securities	'	'	'	'	'	'	'	'	-11	'	'
Net income (loss) applicable to common shares and equivalents	'	'	'	'	'	'	'	'	$3,996	($9,566)	($5,117)
Denominator:	'	'	'	'	'	'	'	'	'	'	'
Weighted average common shares and equivalents outstanding, basic	'	'	'	'	'	'	'	'	12,369,487	12,293,749	12,250,914
Dilutive stock options and awards	'	'	'	'	'	'	'	'	249,000	'	'
Weighted average common shares and equivalents outstanding, diluted	'	'	'	'	'	'	'	'	12,618,158	12,293,749	12,250,914

Recovered_Sheet10

Earnings (Loss) Per Common Share - Additional Information (Detail)	12 Months Ended		3 Months Ended	12 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	31-May-12	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
		Series B Voting Convertible Preferred Stock [Member]	Convertible Common Stock [Member]	Restricted Stock [Member]	Restricted Stock [Member]	Stock Options [Member]	Stock Options [Member]	Stock Options [Member]
Earnings Per Share [Line Items]	'	'	'	'	'	'	'	'
Shares included in weighted average common shares and equivalents computation of basic earnings per share	'	100,000	'	'	'	'	'	'
Shares converted from Series B Preferred Stock into company's common stock	1,000,000	'	1,000,000	'	'	'	'	'
Antidilutive weighted-average restricted stock awards/options excluded from the calculation of diluted earnings (loss) per share	'	'	'	57,443	98,158	896,354	1,648,704	1,325,945

Carolina_Starches_Acquisition_1

Carolina Starches Acquisition - Additional Information (Detail) (Carolina Starches, LLC [Member], USD $)	1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Jan. 31, 2012	Aug. 31, 2013
Carolina Starches, LLC [Member]	'	'
Business Acquisition [Line Items]	'	'
Date of acquisition agreement	'	11-Jan-12
Purchase price	$8.50	'

Carolina_Starches_Acquisition_2

Carolina Starches Acquisition - Purchase Price Allocation to Assets Acquired and Liabilities Assumed (Detail) (USD $)	Aug. 31, 2013	Aug. 31, 2012
In Thousands, unless otherwise specified
Business Acquisition [Line Items]	'	'
Goodwill	$7,978	$7,978
Carolina Starches, LLC [Member]	'	'
Business Acquisition [Line Items]	'	'
Property, plant and equipment	3,947	'
Working capital	4,225	'
Other assets	141	'
Intangible assets	290	'
Goodwill	81	'
Non-current liabilities	-184	'
Total purchase price	$8,500	'

Segment_Reporting_Additional_I

Segment Reporting - Additional Information (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	31-May-13	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	31-May-12	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
									Segment
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Number of segments	'	'	'	'	'	'	'	'	2	'	'
Sales	$117,427	$121,719	$110,082	$118,022	$110,223	$111,283	$103,477	$108,168	$467,250	$433,151	$373,763
Industrial Ingredients [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	356,016	330,607	291,523
Carolina Starches, LLC [Member] | Industrial Ingredients [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	$26,900	'	'

Segment_Reporting_Segment_Wide

Segment Reporting - Segment Wide Reporting Information (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	31-May-13	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	31-May-12	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	$117,427	$121,719	$110,082	$118,022	$110,223	$111,283	$103,477	$108,168	$467,250	$433,151	$373,763
Depreciation and amortization	'	'	'	'	'	'	'	'	13,326	14,127	14,415
Income (loss) from operations	'	'	'	'	'	'	'	'	9,404	10,059	4,445
Capital expenditures, net	'	'	'	'	'	'	'	'	14,199	14,146	8,295
Total assets	224,618	'	'	'	236,179	'	'	'	224,618	236,179	'
Industrial Ingredients [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	356,016	330,607	291,523
Food Ingredients [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	111,234	102,544	82,240
Industrial Starch [Member] | Industrial Ingredients [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	177,382	156,945	127,471
Ethanol [Member] | Industrial Ingredients [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	96,852	101,874	105,730
By-Products [Member] | Industrial Ingredients [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	81,782	71,788	58,322
Operating Segments [Member] | Industrial Ingredients [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Depreciation and amortization	'	'	'	'	'	'	'	'	10,933	10,879	10,812
Income (loss) from operations	'	'	'	'	'	'	'	'	-3,238	-928	-4,718
Capital expenditures, net	'	'	'	'	'	'	'	'	8,997	8,700	6,625
Total assets	133,120	'	'	'	143,039	'	'	'	133,120	143,039	'
Operating Segments [Member] | Food Ingredients [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Depreciation and amortization	'	'	'	'	'	'	'	'	2,061	1,989	2,110
Income (loss) from operations	'	'	'	'	'	'	'	'	23,265	21,591	18,037
Capital expenditures, net	'	'	'	'	'	'	'	'	5,202	5,446	1,663
Total assets	68,550	'	'	'	63,949	'	'	'	68,550	63,949	'
Corporate, Non-Segment [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Depreciation and amortization	'	'	'	'	'	'	'	'	332	1,259	1,493
Income (loss) from operations	'	'	'	'	'	'	'	'	-10,623	-10,604	-8,874
Capital expenditures, net	'	'	'	'	'	'	'	'	'	'	7
Total assets	$22,948	'	'	'	$29,191	'	'	'	$22,948	$29,191	'

Segment_Reporting_Reconciliati

Segment Reporting - Reconciliation of Income (Loss) from Operations for Segments to Income (Loss) Before Income Taxes (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Segment Reporting [Abstract]	'	'	'
Income from operations	$9,404	$10,059	$4,445
Interest expense	-3,989	-8,633	-9,364
Other non-operating income (expense)	75	-6,186	115
Income (loss) before income taxes	$5,490	($4,760)	($4,804)

Segment_Reporting_Sales_Attrib

Segment Reporting - Sales, Attributed to Area to Which Product was Shipped (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Aug. 31, 2013	31-May-13	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	31-May-12	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	$117,427	$121,719	$110,082	$118,022	$110,223	$111,283	$103,477	$108,168	$467,250	$433,151	$373,763
United States [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	429,957	400,070	346,893
Canada [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	8,662	5,653	4,027
Mexico [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	11,419	12,761	9,221
Columbia [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	7,379	6,678	6,802
Japan [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	5,112	4,380	3,434
Other Country [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	4,721	3,609	3,386
Non-United States [Member]	'	'	'	'	'	'	'	'	'	'	'
Revenues from External Customers and Long-Lived Assets [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Sales	'	'	'	'	'	'	'	'	$37,293	$33,081	$26,870

Quarterly_Financial_Data_Unaud2

Quarterly Financial Data (Unaudited) - Summary of Quarterly Financial Data (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Aug. 31, 2013	31-May-13	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	31-May-12	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2011
Quarterly Financial Information Disclosure [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Sales	$117,427	$121,719	$110,082	$118,022	$110,223	$111,283	$103,477	$108,168	$467,250	$433,151	$373,763
Cost of sales	109,830	108,528	99,081	104,764	98,976	99,829	94,076	96,360	422,203	389,241	339,928
Gross margin	7,597	13,191	11,001	13,258	11,247	11,454	9,401	11,808	45,047	43,910	33,835
Net income (loss)	($949)	$2,058	$1,191	$1,707	($4,366)	($5,452)	($340)	$592	$4,007	($9,566)	($5,117)
Earnings (loss) per common share:	'	'	'	'	'	'	'	'	'	'	'
Basic	($0.08)	$0.17	$0.10	$0.14	($0.35)	($0.44)	($0.03)	$0.05	$0.32	($0.78)	($0.42)
Diluted	($0.08)	$0.16	$0.10	$0.14	($0.35)	($0.44)	($0.03)	$0.05	$0.32	($0.78)	($0.42)
Dividends declared	'	'	'	'	'	'	'	'	'	'	'

Quarterly_Financial_Data_Unaud3

Quarterly Financial Data (Unaudited) - Additional Information (Detail) (Series A Preferred Stock [Member], USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Aug. 31, 2012	Aug. 31, 2012
Series A Preferred Stock [Member]	'	'
Quarterly Financial Data [Line Items]	'	'
Stock redeemed	$28.90	'
Original issue price of preferred stock	23.5	40
Accrued dividends	5.4	8.9
Accelerated discount accretion	3.2	5.5
Amortization of issuance costs	$0.60	'

Legal_Proceedings_and_Continge1

Legal Proceedings and Contingencies - Additional Information (Detail) (USD $)	1 Months Ended		3 Months Ended	12 Months Ended	1 Months Ended		12 Months Ended
	Aug. 31, 2013	Apr. 30, 2012	31-May-13	Aug. 31, 2013	Aug. 31, 2013	Aug. 31, 2013	Aug. 31, 2012	Aug. 31, 2010
	Defendant	Patents			Penford Products [Member]	Carolina Starches, LLC [Member]	Australia and New Zealand Discontinued Operations [Member]	Australia and New Zealand Discontinued Operations [Member]
Loss Contingencies [Line Items]	'	'	'	'	'	'	'	'
Number of patents under allegation of patent infringement	'	2	'	'	'	'	'	'
Amount of recovery sought in complaint	'	'	'	'	$778,000	$216,000	'	'
Number of defendant	2	'	'	'	'	'	'	'
Name of defendants	'Penford Products and Carolina Starches, LLC	'	'	'	'	'	'	'
Name of plaintiff	'Pirinate Consulting Group, LLC	'	'	'	'	'	'	'
Litigation settlement receivable amount	'	'	3,400,000	'	'	'	'	'
Litigation settlement receivable net of litigation expenses	'	'	2,100,000	2,106,000	'	'	'	'
Litigation settlement expenses	'	'	300,000	'	'	'	'	'
Amount of proceeds in escrow	'	'	'	'	'	'	'	2,000,000
Escrowed payments received	'	'	'	'	'	'	1,225,000	'
Amount of claim filed by the purchaser of Company's Lane cave	'	'	'	'	'	'	$901,000	'