Quarterly report pursuant to Section 13 or 15(d)

Note 4 - Capital Stock, Stock Plans and Stock Based Compensation (Details) - Stock-based Compensation Recognized

v2.4.1.9
Note 4 - Capital Stock, Stock Plans and Stock Based Compensation (Details) - Stock-based Compensation Recognized (USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Stock Options $ 33,000us-gaap_AllocatedShareBasedCompensationExpense $ (18,000)us-gaap_AllocatedShareBasedCompensationExpense
Employee Stock Option [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Stock Options 13,000us-gaap_AllocatedShareBasedCompensationExpense
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
(39,000)us-gaap_AllocatedShareBasedCompensationExpense
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Director Stock Options [Member]    
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]    
Stock Options $ 20,000us-gaap_AllocatedShareBasedCompensationExpense
/ us-gaap_AwardTypeAxis
= pesi_DirectorStockOptionsMember
$ 21,000us-gaap_AllocatedShareBasedCompensationExpense
/ us-gaap_AwardTypeAxis
= pesi_DirectorStockOptionsMember