Fair Value Measurements Fair Value Measurements - Additional Information (Details) (Fair Value, Measurements, Nonrecurring)	12 Months Ended
Dec. 31, 2012
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of outstanding debt extinguished	98.00%

Extinguishment of Debt, Percent of Outstanding Debt

No definition available.

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Namespace Prefix:	pva_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration