Basis of Presentation	3 Months Ended
Mar. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	1. Basis of Presentation The financial statements included in this report reflect all normal and recurring adjustments which, in the opinion of management, are necessary for a fair presentation of our consolidated financial position at March 31, 2016 and December 31, 2015, the consolidated results of operations for the three months ended March 31, 2016 and 2015, and consolidated cash flows for the three months ended March 31, 2016 and 2015. The unaudited results of operations for the interim periods reported are not necessarily indicative of results to be expected for the full year. The financial statements were prepared in accordance with the requirements of the Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, certain notes or other financial information that are normally required by generally accepted accounting principles (GAAP) in the United States have been condensed or omitted from these interim financial statements. These statements, therefore, should be read in conjunction with the consolidated financial statements and related notes included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2015. In the second quarter of 2015, we established the Bakken Midstream operating segment. See Note 5, Bakken Midstream Joint Venture and Note 9, Segment Information. Certain prior period information has been reclassified to conform to the current period presentation reflecting our two operating segments, Exploration and Production and Bakken Midstream. In the first quarter of 2016, we adopted Accounting Standard Update (ASU) 2015-03, Simplifying the Presentation of Debt Issuance Costs, which requires debt issuance costs to be presented in the balance sheet as a direct reduction to the associated debt liability. The Consolidated Balance Sheet at December 31, 2015 has been recast to reduce Other assets and Long-term debt by $38 million. In the first quarter of 2016, we adopted ASU 2015-02, Amendments to the Consolidation Analysis, which makes changes to both the variable interest model and the voting interest model, which is applicable to all reporting entities involved with limited partnerships or similar entities. The adoption of this standard did not have an impact on our consolidated financial statements. New Accounting Pronouncements: In May 2014, the Financial Accounting Standards Board (FASB) issued ASU 2014-09, Revenue from Contracts with Customers, as a new Accounting Standards Codification (ASC) Topic, ASC 606. This ASU is effective for us beginning in the first quarter of 2018, with early adoption permitted from the first quarter of 2017. We are currently assessing the impact of the ASU on our consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases, as a new ASC Topic, ASC 842. The new standard will require the recognition of assets and liabilities for all leases with lease terms greater than one year, including leases currently treated as operating leases under the existing standard. This ASU is effective for us beginning in the first quarter of 2019, with early adoption permitted. We are currently assessing the impact of the ASU on our consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting. This ASU makes changes to various provisions associated with share-based accounting, including provisions affecting the accounting for income taxes, the accounting for forfeitures, and the consideration of net settlement provisions on the balance sheet classification of the share-based award. This ASU is effective for us beginning in the first quarter of 2017, with early adoption permitted. We are currently assessing the impact of the ASU on our consolidated financial statements.

1. Basis of Presentation

The financial statements included in this report reflect all normal and recurring adjustments which, in the opinion of management, are necessary for a fair presentation of our consolidated financial position at March 31, 2016 and December 31, 2015, the consolidated results of operations for the three months ended March 31, 2016 and 2015, and consolidated cash flows for the three months ended March 31, 2016 and 2015. The unaudited results of operations for the interim periods reported are not necessarily indicative of results to be expected for the full year.

The financial statements were prepared in accordance with the requirements of the Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, certain notes or other financial information that are normally required by generally accepted accounting principles (GAAP) in the United States have been condensed or omitted from these interim financial statements. These statements, therefore, should be read in conjunction with the consolidated financial statements and related notes included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2015.

In the second quarter of 2015, we established the Bakken Midstream operating segment. See Note 5, Bakken Midstream Joint Venture and Note 9, Segment Information. Certain prior period information has been reclassified to conform to the current period presentation reflecting our two operating segments, Exploration and Production and Bakken Midstream.

In the first quarter of 2016, we adopted Accounting Standard Update (ASU) 2015-03, Simplifying the Presentation of Debt Issuance Costs, which requires debt issuance costs to be presented in the balance sheet as a direct reduction to the associated debt liability. The Consolidated Balance Sheet at December 31, 2015 has been recast to reduce Other assets and Long-term debt by $38 million.

In the first quarter of 2016, we adopted ASU 2015-02, Amendments to the Consolidation Analysis, which makes changes to both the variable interest model and the voting interest model, which is applicable to all reporting entities involved with limited partnerships or similar entities. The adoption of this standard did not have an impact on our consolidated financial statements.

New Accounting Pronouncements: In May 2014, the Financial Accounting Standards Board (FASB) issued ASU 2014-09, Revenue from Contracts with Customers, as a new Accounting Standards Codification (ASC) Topic, ASC 606. This ASU is effective for us beginning in the first quarter of 2018, with early adoption permitted from the first quarter of 2017. We are currently assessing the impact of the ASU on our consolidated financial statements.

In February 2016, the FASB issued ASU 2016-02, Leases, as a new ASC Topic, ASC 842. The new standard will require the recognition of assets and liabilities for all leases with lease terms greater than one year, including leases currently treated as operating leases under the existing standard. This ASU is effective for us beginning in the first quarter of 2019, with early adoption permitted. We are currently assessing the impact of the ASU on our consolidated financial statements.

In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting. This ASU makes changes to various provisions associated with share-based accounting, including provisions affecting the accounting for income taxes, the accounting for forfeitures, and the consideration of net settlement provisions on the balance sheet classification of the share-based award. This ASU is effective for us beginning in the first quarter of 2017, with early adoption permitted. We are currently assessing the impact of the ASU on our consolidated financial statements.