Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2014

Accounting Policies [Abstract]

Use of Estimates

Use of Estimates  The preparation of financial statements in accordance with generally accepted accounting principles in the United States requires management to make informed judgments and estimates that affect the reported amounts of assets, liabilities, revenues, and expenses. Management evaluates its estimates and related assumptions regularly, including those related to proved reserves; the value of properties and equipment; goodwill; intangible assets; asset retirement obligations; litigation liabilities; environmental liabilities; pension assets, liabilities, and costs; income taxes; and fair values. Changes in facts and circumstances or additional information may result in revised estimates, and actual results may differ from these estimates.