XML 110 R84.htm IDEA: XBRL DOCUMENT v2.4.1.9
Note 14 - Stockholders' Equity (Details) - Stock-based Compensation Costs (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Stock-based compensation costs $ 3,163us-gaap_ShareBasedCompensation $ 2,806us-gaap_ShareBasedCompensation $ 2,841us-gaap_ShareBasedCompensation
Employee Stock-based Compensation Costs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Stock-based compensation costs 2,426us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= bpz_EmployeeStockBasedCompensationCostsMember		 2,189us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= bpz_EmployeeStockBasedCompensationCostsMember		 2,283us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= bpz_EmployeeStockBasedCompensationCostsMember
Director Stock-based Compensation Costs [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Stock-based compensation costs 730us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= bpz_DirectorStockBasedCompensationCostsMember		 606us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= bpz_DirectorStockBasedCompensationCostsMember		 532us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= bpz_DirectorStockBasedCompensationCostsMember
Employee Stock Purchase Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Stock-based compensation costs $ 7us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= bpz_EmployeeStockPurchasePlanMember		 $ 11us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= bpz_EmployeeStockPurchasePlanMember		 $ 26us-gaap_ShareBasedCompensation
/ us-gaap_AwardTypeAxis
= bpz_EmployeeStockPurchasePlanMember