New Accounting Standards	12 Months Ended
Dec. 31, 2016
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles	New Accounting Standards In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) to provide a framework that replaces the existing revenue recognition guidance, and has since modified the standard with several ASUs.The standard provides that an entity should recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. More specifically, the standard requires entities to recognize revenue through the application of a five-step model, which includes the: (i) identification of the contract; (ii) identification of the performance obligations; (iii) determination of the transaction price; (iv) allocation of the transaction price to the performance obligations; and (v) the recognition of revenue as the entity satisfies the performance obligations. Early adoption of ASU 2014-09 is permitted after December 15, 2016, however, the Company plans to adopt the new standard for reporting periods beginning after December 15, 2017. Under the new standard, companies may use either of the following transition methods: (i) a full retrospective approach reflecting the application of the standard in each prior reporting period with the option to elect certain practical expedients, or (ii) a modified retrospective approach with the cumulative effect of initially adopting ASU 2014-09 recognized at the date of adoption (which includes additional footnote disclosures). The Company has not concluded which transition method it will elect but it currently anticipates using the modified retrospective approach. The Company is currently in the process of evaluating the impact of the new standard on its various revenue and cash flow streams, including the evaluation of the impact, if any, on changes to business processes, systems and controls to support recognition and disclosure under the new guidance. Tariff sales to customers are determined to be in the scope of the new standard and represent a significant portion of the Company’s total operating revenues. The Company has not completed its final evaluation of tariff sales under the new guidance but currently does not anticipate that ASU 2014-09 will have a material impact on the Company's revenue recognition for such sales. The Company is still considering the impacts of the guidance on several industry-related accounting issues, including the accounting for contributions in aid of construction ("CIAC"), assessing the collectability criterion and the presentation of revenues associated with alternative revenue programs. The Company's initial assessment may change as we execute our implementation plan and new guidance is provided by the American Institute of Certified Public Accountants Power and Utilities Industry Task Force. In January 2016, the FASB issued ASU 2016-01, Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Liabilities to enhance the reporting model for financial instruments by addressing certain aspects of recognition, measurement, presentation, and disclosure. ASU 2016-01 generally requires entities to measure equity investments that do not result in consolidation and are not accounted for under the equity method at fair value and recognize any changes in fair value in net income. The guidance for classifying and measuring investments in debt securities and loans is not changed by this ASU, but requires entities to record changes in other comprehensive income. Financial assets and financial liabilities must be separately presented by measurement category on the balance sheet or in the accompanying notes to the financial statements. ASU 2016-01 clarifies the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity's other deferred tax assets. The provisions of this ASU become effective for public companies for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Upon adoption of the new standard, the Company expects to record the cumulative effects as of January 1, 2018 which will result in an adjustment to accumulated other comprehensive income (losses) and retained earnings for unrealized gains (losses) related to equity securities owned by the Company. Had the Company been required to adopt the new standard at January 1, 2016, accumulated other comprehensive income would decrease by $28.8 million and retained earnings would increase by a corresponding amount. Furthermore, the Company would report for the year ended December 31, 2016 an increase in investment income of $1.2 million, an increase in income tax expense of $0.2 million and a decrease in other comprehensive income of $1.0 million. The Company is continuing to assess the future impact of this ASU. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requiring qualitative and quantitative disclosures on leasing agreements. ASU 2016-02 maintains a distinction between finance leases and operating leases similar to the distinction under previous leases guidance for capital leases and operating leases. The impact of leases reported in the Company's operating results and statement of cash flows are expected to be similar to previous GAAP. ASU 2016-02 requires the recognition in the statement of financial position, by the lessee, of a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. How leases are recorded in regard to financial position represents a significant change from previous GAAP guidance. The lessee is permitted to make an accounting policy election to not recognize lease assets and lease liabilities for short-term leases. Implementation of the standard for public companies will be required for annual reporting periods beginning after December 15, 2018 and interim periods within that reporting period. Early adoption of ASU 2016-02 is permitted for all entities, however, the Company plans to adopt the new standard for reporting periods beginning after December 15, 2018. Adoption of the new lease accounting standard will require the Company to apply the new standard to the earliest period using a modified retrospective approach. The Company is currently in the process of evaluating the impact of the new standard, including the evaluation of the impact, if any, on changes to business processes, systems and controls to support recognition and disclosure under the new guidance, however, at this time is unable to determine the impact this standard will have on the financial statements and related disclosures. In March 2016, the FASB issued ASU 2016-09, Compensation - Stock Compensation (Topic 718) Improvements to Employee Share-Based Payment Accounting to simplify the accounting for share-based payment transactions, including the income tax consequences, classification of awards either as equity or liabilities, and classification on the statements of cash flows. The Company will adopt the new standard effective January 1, 2017 and does not expect the effect of the adoption to be material to the Company's financial condition, results of operations or cash flows. The cumulative effect of the adoption of the new standard will be to increase net operating loss carryforward deferred tax assets and retained earnings by approximately $0.2 million on January 1, 2017. The Company also expects to continue to account for its outstanding stock awards based on the equity method and therefore does not anticipate any changes in reporting related compensation expense. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326) ("ASU 2016-13"). ASU 2016-13 changes how companies measure and recognize credit impairment for many financial assets. The new current expected credit loss model will require companies to immediately recognize an estimate of credit losses expected to occur over the remaining life of the financial assets that are in the scope of the standard. The ASU also makes targeted amendments to the current impairment model for available-for-sale debt securities. For public business entities, the provisions of ASU 2016-13 are effective for fiscal years and interim periods within that reporting period beginning after December 15, 2019. Early implementation is permitted as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. ASU 2016-13 will be applied in a modified-retrospective approach through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is implemented. The Company is currently assessing the future impact of ASU 2016-13. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230) Classification of Certain Cash Receipts and Cash Payments to reduce diversity in practice in how certain cash receipts and cash payments are classified in the statement of cash flows. The new guidance addresses the following classification issues: debt prepayment or debt extinguishment costs; settlement of zero-coupon bonds; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. For public business entities, the provisions of ASU 2016-15 are effective for fiscal years and interim periods within that reporting period beginning after December 15, 2017. Early adoption is permitted, including adoption in an interim period. If an entity elects early adoption of ASU 2016-15 in an interim period, adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. An entity that elects early adoption must adopt all of the amendments in the same period. ASU 2016-15 will be applied using a retrospective transition method to each period presented. If it is impracticable to apply ASU 2016-15 retrospectively for some of the issues, the amendments for those issues may be applied prospectively as of the earliest date practicable. The Company is currently assessing the future impact of this ASU. In December 2016, the FASB issued ASU 2016-19, Technical Corrections and Improvements, which amends a number of Topics in the FASB ASC. This ASU is part of an ongoing FASB project to facilitate Codification updates for non-substantive technical corrections, clarifications, and improvements that are not expected to have a significant effect on accounting practice or create a significant administrative cost to most entities. Most of the amendments are effective upon issuance of ASU 2016-19 while certain amendments that require transition guidance are effective for the Company beginning January 1, 2017. The Company believes it is in compliance with those amendments that are effective immediately and that are applicable to the Company. The Company has not completed its evaluation of the new standard for amendments that require transition guidance.

New Accounting Standards

In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) to provide a framework that replaces the existing revenue recognition guidance, and has since modified the standard with several ASUs.The standard provides that an entity should recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. More specifically, the standard requires entities to recognize revenue through the application of a five-step model, which includes the: (i) identification of the contract; (ii) identification of the performance obligations; (iii) determination of the transaction price; (iv) allocation of the transaction price to the performance obligations; and (v) the recognition of revenue as the entity satisfies the performance obligations. Early adoption of ASU 2014-09 is permitted after December 15, 2016, however, the Company plans to adopt the new standard for reporting periods beginning after December 15, 2017.

Under the new standard, companies may use either of the following transition methods: (i) a full retrospective approach reflecting the application of the standard in each prior reporting period with the option to elect certain practical expedients, or (ii) a modified retrospective approach with the cumulative effect of initially adopting ASU 2014-09 recognized at the date of adoption (which includes additional footnote disclosures). The Company has not concluded which transition method it will elect but it currently anticipates using the modified retrospective approach.

The Company is currently in the process of evaluating the impact of the new standard on its various revenue and cash flow streams, including the evaluation of the impact, if any, on changes to business processes, systems and controls to support recognition and disclosure under the new guidance. Tariff sales to customers are determined to be in the scope of the new standard and represent a significant portion of the Company’s total operating revenues. The Company has not completed its final evaluation of tariff sales under the new guidance but currently does not anticipate that ASU 2014-09 will have a material impact on the Company's revenue recognition for such sales. The Company is still considering the impacts of the guidance on several industry-related accounting issues, including the accounting for contributions in aid of construction ("CIAC"), assessing the collectability criterion and the presentation of revenues associated with alternative revenue programs. The Company's initial assessment may change as we execute our implementation plan and new guidance is provided by the American Institute of Certified Public Accountants Power and Utilities Industry Task Force.

In January 2016, the FASB issued ASU 2016-01, Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Liabilities to enhance the reporting model for financial instruments by addressing certain aspects of recognition, measurement, presentation, and disclosure. ASU 2016-01 generally requires entities to measure equity investments that do not result in consolidation and are not accounted for under the equity method at fair value and recognize any changes in fair value in net income. The guidance for classifying and measuring investments in debt securities and loans is not changed by this ASU, but requires entities to record changes in other comprehensive income. Financial assets and financial liabilities must be separately presented by measurement category on the balance sheet or in the accompanying notes to the financial statements. ASU 2016-01 clarifies the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity's other deferred tax assets. The provisions of this ASU become effective for public companies for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Upon adoption of the new standard, the Company expects to record the cumulative effects as of January 1, 2018 which will result in an adjustment to accumulated other comprehensive income (losses) and retained earnings for unrealized gains (losses) related to equity securities owned by the Company. Had the Company been required to adopt the new standard at January 1, 2016, accumulated other comprehensive income would decrease by $28.8 million and retained earnings would increase by a corresponding amount. Furthermore, the Company would report for the year ended December 31, 2016 an increase in investment income of $1.2 million, an increase in income tax expense of $0.2 million and a decrease in other comprehensive income of $1.0 million. The Company is continuing to assess the future impact of this ASU.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requiring qualitative and quantitative disclosures on leasing agreements. ASU 2016-02 maintains a distinction between finance leases and operating leases similar to the distinction under previous leases guidance for capital leases and operating leases. The impact of leases reported in the Company's operating results and statement of cash flows are expected to be similar to previous GAAP. ASU 2016-02 requires the recognition in the statement of financial position, by the lessee, of a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. How leases are recorded in regard to financial position represents a significant change from previous GAAP guidance. The lessee is permitted to make an accounting policy election to not recognize lease assets and lease liabilities for short-term leases. Implementation of the standard for public companies will be required for annual reporting periods beginning after December 15, 2018 and interim periods within that reporting period. Early adoption of ASU 2016-02 is permitted for all entities, however, the Company plans to adopt the new standard for reporting periods beginning after December 15, 2018. Adoption of the new lease accounting standard will require the Company to apply the new standard to the earliest period using a modified retrospective approach. The Company is currently in the process of evaluating the impact of the new standard, including the evaluation of the impact, if any, on changes to business processes, systems and controls to support recognition and disclosure under the new guidance, however, at this time is unable to determine the impact this standard will have on the financial statements and related disclosures.

In March 2016, the FASB issued ASU 2016-09, Compensation - Stock Compensation (Topic 718) Improvements to Employee Share-Based Payment Accounting to simplify the accounting for share-based payment transactions, including the income tax consequences, classification of awards either as equity or liabilities, and classification on the statements of cash flows. The Company will adopt the new standard effective January 1, 2017 and does not expect the effect of the adoption to be material to the Company's financial condition, results of operations or cash flows. The cumulative effect of the adoption of the new standard will be to increase net operating loss carryforward deferred tax assets and retained earnings by approximately $0.2 million on January 1, 2017. The Company also expects to continue to account for its outstanding stock awards based on the equity method and therefore does not anticipate any changes in reporting related compensation expense.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326) ("ASU 2016-13"). ASU 2016-13 changes how companies measure and recognize credit impairment for many financial assets. The new current expected credit loss model will require companies to immediately recognize an estimate of credit losses expected to occur over the remaining life of the financial assets that are in the scope of the standard. The ASU also makes targeted amendments to the current impairment model for available-for-sale debt securities. For public business entities, the provisions of ASU 2016-13 are effective for fiscal years and interim periods within that reporting period beginning after December 15, 2019. Early implementation is permitted as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. ASU 2016-13 will be applied in a modified-retrospective approach through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is implemented. The Company is currently assessing the future impact of ASU 2016-13.

In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230) Classification of Certain Cash Receipts and Cash Payments to reduce diversity in practice in how certain cash receipts and cash payments are classified in the statement of cash flows. The new guidance addresses the following classification issues: debt prepayment or debt extinguishment costs; settlement of zero-coupon bonds; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. For public business entities, the provisions of ASU 2016-15 are effective for fiscal years and interim periods within that reporting period beginning after December 15, 2017. Early adoption is permitted, including adoption in an interim period. If an entity elects early adoption of ASU 2016-15 in an interim period, adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. An entity that elects early adoption must adopt all of the amendments in the same period. ASU 2016-15 will be applied using a retrospective transition method to each period presented. If it is impracticable to apply ASU 2016-15 retrospectively for some of the issues, the amendments for those issues may be applied prospectively as of the earliest date practicable. The Company is currently assessing the future impact of this ASU.

In December 2016, the FASB issued ASU 2016-19, Technical Corrections and Improvements, which amends a number of Topics in the FASB ASC. This ASU is part of an ongoing FASB project to facilitate Codification updates for non-substantive technical corrections, clarifications, and improvements that are not expected to have a significant effect on accounting practice or create a significant administrative cost to most entities. Most of the amendments are effective upon issuance of ASU 2016-19 while certain amendments that require transition guidance are effective for the Company beginning January 1, 2017. The Company believes it is in compliance with those amendments that are effective immediately and that are applicable to the Company. The Company has not completed its evaluation of the new standard for amendments that require transition guidance.