Basis of Presentation	6 Months Ended
Jun. 30, 2015
Accounting Policies [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 the Corporation’s consolidated financial position at June 30, 2015 and December 31, 2014, the consolidated results of operations for the three months and six months ended June 30, 2015 and 2014, and consolidated cash flows for the six months ended June 30, 2015 and 2014. 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 U.S. generally accepted accounting principles (GAAP) 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, 2014. The statements of consolidated income for the three months and six months ended June 30, 2014 and consolidated cash flows for the six months ended June 30, 2014, have been recast to reflect the Corporation’s energy trading joint venture, HETCO, which was sold in February 2015, as discontinued operations. In Note 12, Segment Information, the Corporation has reported a new operating segment to reflect the establishment of the Bakken Midstream operating segment in the second quarter of 2015 and have presented prior period numbers on a comparable basis. See Note 14, Subsequent Event; in Notes to Consolidated Financial Statements for further information. Certain information in the financial statements and notes has been reclassified to conform to the current period presentation. New Accounting Pronouncements: In April 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. The ASU amends the criteria for reporting discontinued operations to include only disposals representing a strategic shift in operations. The ASU also requires expanded disclosures regarding the assets, liabilities, income, and expenses of discontinued operations. This ASU became effective for the Corporation in the first quarter of 2015 and did not have a significant impact on its consolidated financial statements. In May 2014, the 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 the Corporation beginning in the first quarter of 2018, with early adoption permitted from the first quarter of 2017. The Corporation is currently assessing the impact of the ASU on its consolidated financial statements. In February 2015, the FASB issued ASU 2015-02, Amendments to the Consolidation Analysis, which makes changes to both the variable interest model and the voting model, affecting all reporting entities involved with limited partnerships or similar entities. This ASU is effective for the Corporation beginning in the first quarter of 2016, with early adoption permitted. The Corporation is currently assessing the impact of the ASU on its consolidated financial statements. In April 2015, the FASB issued 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 deduction from the associated debt liability. This ASU is effective for the Corporation beginning in the first quarter of 2016, with early adoption permitted. The Corporation does not expect that the ASU will have a material impact to its 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 the Corporation’s consolidated financial position at June 30, 2015 and December 31, 2014, the consolidated results of operations for the three months and six months ended June 30, 2015 and 2014, and consolidated cash flows for the six months ended June 30, 2015 and 2014. 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 U.S. generally accepted accounting principles (GAAP) 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, 2014.

The statements of consolidated income for the three months and six months ended June 30, 2014 and consolidated cash flows for the six months ended June 30, 2014, have been recast to reflect the Corporation’s energy trading joint venture, HETCO, which was sold in February 2015, as discontinued operations. In Note 12, Segment Information, the Corporation has reported a new operating segment to reflect the establishment of the Bakken Midstream operating segment in the second quarter of 2015 and have presented prior period numbers on a comparable basis. See Note 14, Subsequent Event; in Notes to Consolidated Financial Statements for further information. Certain information in the financial statements and notes has been reclassified to conform to the current period presentation.

New Accounting Pronouncements: In April 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. The ASU amends the criteria for reporting discontinued operations to include only disposals representing a strategic shift in operations. The ASU also requires expanded disclosures regarding the assets, liabilities, income, and expenses of discontinued operations. This ASU became effective for the Corporation in the first quarter of 2015 and did not have a significant impact on its consolidated financial statements.

In May 2014, the 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 the Corporation beginning in the first quarter of 2018, with early adoption permitted from the first quarter of 2017. The Corporation is currently assessing the impact of the ASU on its consolidated financial statements.

In February 2015, the FASB issued ASU 2015-02, Amendments to the Consolidation Analysis, which makes changes to both the variable interest model and the voting model, affecting all reporting entities involved with limited partnerships or similar entities. This ASU is effective for the Corporation beginning in the first quarter of 2016, with early adoption permitted. The Corporation is currently assessing the impact of the ASU on its consolidated financial statements.

In April 2015, the FASB issued 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 deduction from the associated debt liability. This ASU is effective for the Corporation beginning in the first quarter of 2016, with early adoption permitted. The Corporation does not expect that the ASU will have a material impact to its consolidated financial statements.