Annual report pursuant to Section 13 and 15(d)

Note 6 - Capital Stock, Stock Plans, Warrants, and Stock Based Compensation (Details) - Black-Scholes Valuation Model Assumptions

v2.4.1.9
Note 6 - Capital Stock, Stock Plans, Warrants, and Stock Based Compensation (Details) - Black-Scholes Valuation Model Assumptions (USD $)
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Employee Stock Option [Member]    
Note 6 - Capital Stock, Stock Plans, Warrants, and Stock Based Compensation (Details) - Black-Scholes Valuation Model Assumptions [Line Items]    
Weighted-average fair value per share (in Dollars per share) $ 2.88us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember 		 
Risk -free interest rate (1) 1.91%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember 		[1]  
Expected volatility of stock (2) 61.84%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember 		[2]  
Dividend yield 0.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember 		 
Expected option life (years) (3) 6 years [3]  
Outside Director Stock Options Granted [Member] | Minimum [Member]    
Note 6 - Capital Stock, Stock Plans, Warrants, and Stock Based Compensation (Details) - Black-Scholes Valuation Model Assumptions [Line Items]    
Weighted-average fair value per share (in Dollars per share)   $ 2.06us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice
/ us-gaap_AwardTypeAxis
= pesi_OutsideDirectorStockOptionsGrantedMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Risk -free interest rate (1)      [1]
Expected volatility of stock (2)      [2]
Dividend yield   0.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
/ us-gaap_AwardTypeAxis
= pesi_OutsideDirectorStockOptionsGrantedMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
Expected option life (years) (3)   10 years [3]
Outside Director Stock Options Granted [Member]    
Note 6 - Capital Stock, Stock Plans, Warrants, and Stock Based Compensation (Details) - Black-Scholes Valuation Model Assumptions [Line Items]    
Weighted-average fair value per share (in Dollars per share) $ 2.73us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExercisePrice
/ us-gaap_AwardTypeAxis
= pesi_OutsideDirectorStockOptionsGrantedMember 		 
Risk -free interest rate (1) 2.63%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
/ us-gaap_AwardTypeAxis
= pesi_OutsideDirectorStockOptionsGrantedMember 		[1]  
Expected volatility of stock (2) 59.59%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate
/ us-gaap_AwardTypeAxis
= pesi_OutsideDirectorStockOptionsGrantedMember 		[2]  
Dividend yield 0.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
/ us-gaap_AwardTypeAxis
= pesi_OutsideDirectorStockOptionsGrantedMember 		 
Expected option life (years) (3) 10 years [3]  
[1] The risk-free interest rate is based on the U.S. Treasury yield in effect at the grant date over the expected term of the option.
[2] The expected volatility is based on historical volatility from our traded Common Stock over the expected term of the option.
[3] The expected option life is based on historical exercises and post-vesting data.