Note 8 - Investment in Ecuador Property (Details) - Income (Expense) from the Investment in the Ecuador Property (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income (Expense) from the Investment in the Ecuador Property [Abstract]
Distributions received from investment in Ecuador property	$ 250	$ 0	$ 250
Amortization of investment in Ecuador property	(34)	(47)	(81)	(94)
Income (loss) from investment in Ecuador property, net	$ 216	$ (47)	$ 169	$ (94)

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