Note 9 - Investment in Ecuador Property (Details) - Income (Loss) from the Investment in the Ecuador Property (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income (Loss) from the Investment in the Ecuador Property [Abstract]
Distributions received from investment in Ecuador property	$ 250	$ 250	$ 250
Amortization of investment in Ecuador property	(33)bpz_AmortizationOfInvestmentProperty	(98)bpz_AmortizationOfInvestmentProperty	(188)bpz_AmortizationOfInvestmentProperty
Income from investment in Ecuador property, net	$ 217	$ 152	$ 62

This element represents the amount of cash received or paid recognized as income (expense) related to the entity's investment in oil and gas property accounted for under the cost method, net of amortization.

No definition available.

Name:	bpz_IncomeExpenseFromInvestmentPropertyNetOfAmortization
Namespace Prefix:	bpz_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration