Balance Sheet Parenthetical (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Oil and Gas Property, Successful Effort Method, Accumulated Depreciation, Depletion and Amortization	$ 2,865,627	$ 3,233,012
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	200,000,000us-gaap_CommonStockSharesAuthorized	200,000,000us-gaap_CommonStockSharesAuthorized
Common Stock, Shares, Issued	67,464,185us-gaap_CommonStockSharesIssued	67,463,060us-gaap_CommonStockSharesIssued
Common Stock, Shares, Outstanding	67,464,185us-gaap_CommonStockSharesOutstanding	67,463,060us-gaap_CommonStockSharesOutstanding
Treasury Stock, Shares	0us-gaap_TreasuryStockShares	0us-gaap_TreasuryStockShares
Assets Held-for-sale [Member]
Oil and Gas Property, Successful Effort Method, Accumulated Depreciation, Depletion and Amortization	580,637	22,482
Other Capitalized Property Plant and Equipment [Member]
Oil and Gas Property, Successful Effort Method, Accumulated Depreciation, Depletion and Amortization	$ 35,590	$ 37,079

Face amount or stated value per share of common stock.

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