Acquisitions and Dispositions (Details 2) (USD $) In Millions, unless otherwise specified	1 Months Ended	6 Months Ended
Aug. 31, 2011	Jun. 30, 2011
Notes (Details)
Negative proceeds on sale of oil and gas properties		$ 2.8
Group of sold properties representing a percentage of year-end proved reserves	300.00%	1200.00%

Gain or loss recorded from sale of oil and gas properties, includes the realized gains (losses) on the sale of proved and unproved oil and gas properties.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 19

-Paragraph 41, 44, 45, 46, 47

Name:	us-gaap_GainLossOnSaleOfOilAndGasProperty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration