| Note 9 - Long-term Debt (Details) (USD $)
 | 0 Months Ended | 12 Months Ended | 0 Months Ended | 3 Months Ended | 0 Months Ended | 12 Months Ended |  |  | 
| Aug. 02, 2013 | Dec. 31, 2014 | Apr. 14, 2014 | Jun. 30, 2014 | Jun. 30, 2014 | Dec. 31, 2013 | Oct. 31, 2011 | Feb. 12, 2013 | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Debt Instrument, Unamortized Discount |  | 137,000us-gaap_DebtInstrumentUnamortizedDiscount |  |  |  | $ 223,000us-gaap_DebtInstrumentUnamortizedDiscount |  |  | 
| Debt Instrument, Face Amount | 3,000,000us-gaap_DebtInstrumentFaceAmount |  |  |  |  |  |  |  | 
| Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per share) |  | 2.23us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 |  |  |  |  |  |  | 
| Common Stock, Shares, Issued (in Shares) |  | 11,476,485us-gaap_CommonStockSharesIssued |  |  |  | 11,406,573us-gaap_CommonStockSharesIssued |  |  | 
| Warrant [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Fair Value Assumptions, Expected Volatility Rate | 55.54%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_FinancialInstrumentAxis
 = us-gaap_WarrantMember
 |  |  |  |  |  |  |  | 
| Fair Value Assumptions, Risk Free Interest Rate | 0.59%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_FinancialInstrumentAxis
 = us-gaap_WarrantMember
 |  |  |  |  |  |  |  | 
| Fair Value Assumptions, Expected Term | 3 years |  |  |  |  |  |  |  | 
| Fair Value Assumptions, Expected Dividend Rate | 0.00%us-gaap_FairValueAssumptionsExpectedDividendRate / us-gaap_FinancialInstrumentAxis
 = us-gaap_WarrantMember
 |  |  |  |  |  |  |  | 
| Lenders [Member] | Promissory Note dated August 2, 2013 [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Proceeds from Issuance of Long-term Debt | 3,000,000us-gaap_ProceedsFromIssuanceOfLongTermDebt / us-gaap_LongtermDebtTypeAxis
 = pesi_PromissoryNoteDatedAugustSecond2013Member
 / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
 = pesi_LendersMember
 |  |  |  |  |  |  |  | 
| Number of Shares Issued to Each Lender on Warrant (in Shares) | 35,000pesi_NumberOfSharesIssuedToEachLenderOnWarrant / us-gaap_LongtermDebtTypeAxis
 = pesi_PromissoryNoteDatedAugustSecond2013Member
 / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
 = pesi_LendersMember
 |  |  |  |  |  |  |  | 
| Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per share) | 2.23us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 / us-gaap_LongtermDebtTypeAxis
 = pesi_PromissoryNoteDatedAugustSecond2013Member
 / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
 = pesi_LendersMember
 |  |  |  |  |  |  |  | 
| Warrants Exercisable Term | 6 months |  |  |  |  |  |  |  | 
| Warrants Not Settleable in Cash, Fair Value Disclosure | 59,000us-gaap_WarrantsNotSettleableInCashFairValueDisclosure / us-gaap_LongtermDebtTypeAxis
 = pesi_PromissoryNoteDatedAugustSecond2013Member
 / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
 = pesi_LendersMember
 |  |  |  |  |  |  |  | 
| Common Stock, Shares, Issued (in Shares) | 90,000us-gaap_CommonStockSharesIssued / us-gaap_LongtermDebtTypeAxis
 = pesi_PromissoryNoteDatedAugustSecond2013Member
 / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
 = pesi_LendersMember
 |  |  |  |  |  |  |  | 
| Number of Shares Received by each Lender (in Shares) | 45,000pesi_NumberOfSharesReceivedByEachLender / us-gaap_LongtermDebtTypeAxis
 = pesi_PromissoryNoteDatedAugustSecond2013Member
 / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
 = pesi_LendersMember
 |  |  |  |  |  |  |  | 
| Stock Issued During Period, Value, Other | 200,000us-gaap_StockIssuedDuringPeriodValueOther / us-gaap_LongtermDebtTypeAxis
 = pesi_PromissoryNoteDatedAugustSecond2013Member
 / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
 = pesi_LendersMember
 |  |  |  |  |  |  |  | 
| Maximum Number of Payoffs of Shares in Terms of Outstanding Equity |  | 20.00%pesi_MaximumNumberOfPayoffsOfSharesInTermsOfOutstandingEquity / us-gaap_LongtermDebtTypeAxis
 = pesi_PromissoryNoteDatedAugustSecond2013Member
 / us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
 = pesi_LendersMember
 |  |  |  |  |  |  | 
| Amended Loan Agreement [Member] | Term Loan [Member] | Minimum [Member] | PNC Bank [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Minimum Fixed Charge Coverage Ratio |  | 25pesi_MinimumFixedChargeCoverageRatio / us-gaap_DebtInstrumentAxis
 = pesi_AmendedLoanAgreementMember
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 / us-gaap_LongtermDebtTypeAxis
 = pesi_TermLoanMember
 / us-gaap_RangeAxis
 = us-gaap_MinimumMember
 |  |  |  |  |  |  | 
| Amended Loan Agreement [Member] | Revolving Credit Facility [Member] | PNC Bank [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Line of Credit Facility, Maximum Borrowing Capacity |  |  |  |  |  |  | 12,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis
 = us-gaap_RevolvingCreditFacilityMember
 / us-gaap_DebtInstrumentAxis
 = pesi_AmendedLoanAgreementMember
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 |  | 
| Amendment 4 [Member] | Term Loan [Member] | PNC Bank [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Line of Credit Facility, Maximum Borrowing Capacity |  |  | 16,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_DebtInstrumentAxis
 = pesi_Amendment4Member
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 / us-gaap_LongtermDebtTypeAxis
 = pesi_TermLoanMember
 |  |  |  |  |  | 
| Debt Instrument, Periodic Payment, Principal |  |  | 190,000us-gaap_DebtInstrumentPeriodicPaymentPrincipal / us-gaap_DebtInstrumentAxis
 = pesi_Amendment4Member
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 / us-gaap_LongtermDebtTypeAxis
 = pesi_TermLoanMember
 |  |  |  |  |  | 
| Debt Instrument, Term |  |  | 7 years |  |  |  |  |  | 
| Gains (Losses) on Restructuring of Debt |  |  |  | (37,000)us-gaap_GainsLossesOnRestructuringOfDebt / us-gaap_DebtInstrumentAxis
 = pesi_Amendment4Member
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 / us-gaap_LongtermDebtTypeAxis
 = pesi_TermLoanMember
 |  |  |  |  | 
| Amended Minimum Fixed Charge Coverage Ratio |  | 15pesi_AmendedMinimumFixedChargeCoverageRatio / us-gaap_DebtInstrumentAxis
 = pesi_Amendment4Member
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 / us-gaap_LongtermDebtTypeAxis
 = pesi_TermLoanMember
 |  |  |  |  |  |  | 
| Amendment 4 [Member] | Revolving Credit Facility [Member] | PNC Bank [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Line of Credit Facility, Maximum Borrowing Capacity |  |  | 18,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis
 = us-gaap_RevolvingCreditFacilityMember
 / us-gaap_DebtInstrumentAxis
 = pesi_Amendment4Member
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 |  |  |  |  |  | 
| Amendment 4 [Member] | PNC Bank [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Debt Instrument, Fee Amount |  | 30,000us-gaap_DebtInstrumentFeeAmount / us-gaap_DebtInstrumentAxis
 = pesi_Amendment4Member
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 |  |  |  |  |  |  | 
| Amendment 5 [Member] | PFSG [Member] | PNC Bank [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Proceeds from Insurance Settlement, Investing Activities |  |  |  |  | 3,850,000us-gaap_ProceedsFromInsuranceSettlementInvestingActivities / us-gaap_DebtInstrumentAxis
 = pesi_Amendment5Member
 / us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
 = pesi_PFSGMember
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 |  |  |  | 
| Amendment 6 [Member] | PNC Bank [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Debt Instrument, Fee Amount |  |  |  | 15,000us-gaap_DebtInstrumentFeeAmount / us-gaap_DebtInstrumentAxis
 = pesi_Amendment6Member
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 | 15,000us-gaap_DebtInstrumentFeeAmount / us-gaap_DebtInstrumentAxis
 = pesi_Amendment6Member
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 |  |  |  | 
| Line of Credit Facility Reduction |  |  |  |  | 1,500,000pesi_LineOfCreditFacilityReduction / us-gaap_DebtInstrumentAxis
 = pesi_Amendment6Member
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 |  |  |  | 
| Line of Credit Facility, Current Borrowing Capacity |  | 7,402,000us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity / us-gaap_DebtInstrumentAxis
 = pesi_Amendment6Member
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_PNCBankMember
 |  |  |  |  |  |  | 
| Promissory Notes and Installment Agreements [Member] | Promissory Note dated February 12, 2013 ("New Note") [Member] | TNC [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Number of Days for Trading of Common Stock to Determine Average Closing Price |  | 30 days |  |  |  |  |  |  | 
| Promissory Notes and Installment Agreements [Member] | TNC [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Debt Instrument, Annual Principal Payment |  |  |  |  |  |  |  | 230,000us-gaap_DebtInstrumentAnnualPrincipalPayment / us-gaap_DebtInstrumentAxis
 = pesi_PromissoryNotesAndInstallmentAgreementsMember
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_TNCMember
 | 
| Debt Instrument, Face Amount |  |  |  |  |  |  |  | 1,460,000us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis
 = pesi_PromissoryNotesAndInstallmentAgreementsMember
 / us-gaap_LineOfCreditFacilityAxis
 = pesi_TNCMember
 | 
| Promissory Note dated August 2, 2013 [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Debt Instrument, Unamortized Discount |  | (137,000)us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_LongtermDebtTypeAxis
 = pesi_PromissoryNoteDatedAugustSecond2013Member
 |  |  |  | (223,000)us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_LongtermDebtTypeAxis
 = pesi_PromissoryNoteDatedAugustSecond2013Member
 |  |  | 
| Capital Lease Obligations [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Debt Instrument, Interest Rate, Stated Percentage |  | 6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_LongtermDebtTypeAxis
 = us-gaap_CapitalLeaseObligationsMember
 |  |  |  |  |  |  | 
| Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum |  | 5.30%us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMinimum / us-gaap_LongtermDebtTypeAxis
 = us-gaap_CapitalLeaseObligationsMember
 |  |  |  |  |  |  | 
| Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum |  | 7.10%us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMaximum / us-gaap_LongtermDebtTypeAxis
 = us-gaap_CapitalLeaseObligationsMember
 |  |  |  |  |  |  | 
| PFSG [Member] |  |  |  |  |  |  |  |  | 
| Note 9 - Long-term Debt (Details) [Line Items] |  |  |  |  |  |  |  |  | 
| Proceeds from Insurance Settlement, Investing Activities |  |  |  |  |  | $ 1,500,000us-gaap_ProceedsFromInsuranceSettlementInvestingActivities / us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis
 = pesi_PFSGMember
 |  |  |