2.4.0.8131 - Disclosure - Business - Additional Information (Detail)truefalseIn Millions, unless otherwise specifiedfalse1false falsefalseeol_PE9760----1210-Q0014_STD_91_20121130_0http://www.sec.gov/CIK0000739608duration2012-09-01T00:00:002012-11-30T00:00:00SegmentStandardhttp://www.penx.com/20121130Segmentpenx02false USDtruefalse$eol_PE9760----1210-Q0014_STD_31_20120131_0_581281x815846http://www.sec.gov/CIK0000739608duration2012-01-01T00:00:002012-01-31T00:00:00falsefalseCarolina Starches, LLC [Member]us-gaap_BusinessAcquisitionAxisxbrldihttp://xbrl.org/2006/xbrldipenx_CarolinaStarchesLlcMemberus-gaap_BusinessAcquisitionAxisexplicitMemberiso4217_USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 3penx_BusinessAndOrganizationLineItemspenx_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Business And Organization [Line Items]2false 4us-gaap_NumberOfReportableSegmentsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse22falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:integerItemTypeintegerNumber of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.No definition available.false256Number of segments3false 4us-gaap_PaymentsToAcquireBusinessesGrossus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse85000008.5USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3213-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15, 17 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Purchase pricefalseBusiness - Additional Information (Detail) (USD $)HundredThousandsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.penx.com/taxonomy/role/DisclosureBusinessAdditionalInformation23