Document and Entity Information
Document and Entity Information Document - USD ($) | 12 Months Ended | ||
Dec. 31, 2019 | Jan. 31, 2020 | Jun. 30, 2019 | |
Document and Entity Information [Abstract] | |||
Document Type | 10-K | ||
Document Annual Report | true | ||
Document Period End Date | Dec. 31, 2019 | ||
Document Transition Report | false | ||
Entity File Number | 1-07978 | ||
Entity Registrant Name | BLACK HILLS POWER, INC. | ||
Entity Incorporation, State or Country Code | SD | ||
Entity Tax Identification Number | 46-0111677 | ||
Entity Address, Address Line One | 7001 Mount Rushmore Road | ||
Entity Address, City or Town | Rapid City | ||
Entity Address, State or Province | SD | ||
Entity Address, Postal Zip Code | 57702 | ||
City Area Code | (605) | ||
Local Phone Number | 721-1700 | ||
Title of 12(g) Security | None | ||
Entity Well-known seasoned Issuer | No | ||
Entity Voluntary Filers | Yes | ||
Entity Current Reporting Status | Yes | ||
Entity Interactive Data Current | Yes | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Small Business | false | ||
Entity Emerging Growth Company | false | ||
Entity Shell Company | false | ||
Public Float | $ 0 | ||
Entity Common Stock Share Outstanding | 23,416,396 | ||
Entity Central Index Key | 0000012400 | ||
Amendment Flag | false | ||
Document Fiscal Year End Focus | 2019 | ||
Document Fiscal Period Focus | FY | ||
Current Fiscal Year End Date | --12-31 |
Statements of Income
Statements of Income - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Income Statement [Abstract] | |||
Revenue | $ 291,219 | $ 298,080 | $ 288,433 |
Operating expenses: | |||
Fuel and purchased power | 73,115 | 92,886 | 87,638 |
Operations and maintenance | 84,661 | 79,523 | 74,064 |
Depreciation and amortization | 41,322 | 39,649 | 35,862 |
Taxes - property | 8,184 | 7,687 | 7,043 |
Total operating expenses | 207,282 | 219,745 | 204,607 |
Operating income | 83,937 | 78,335 | 83,826 |
Other income (expense): | |||
Interest expense | (23,972) | (22,545) | (22,421) |
AFUDC - borrowed | 1,437 | 521 | 1,137 |
Interest income | 817 | 676 | 904 |
AFUDC - equity | 0 | 221 | 2,165 |
Other income (expense), net | (5,816) | (891) | (185) |
Total other income (expense) | (27,534) | (22,018) | (18,400) |
Income before income taxes | 56,403 | 56,317 | 65,426 |
Income tax expense | (9,501) | (10,672) | (14,128) |
Net income | $ 46,902 | $ 45,645 | $ 51,298 |
Statements of Comprehensive Inc
Statements of Comprehensive Income - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Statement of Comprehensive Income [Abstract] | |||
Net income | $ 46,902 | $ 45,645 | $ 51,298 |
Benefit plan liability adjustments - net gain (loss) (net of tax of $83, $(62), and $50 respectively) | (312) | 235 | (94) |
Benefit plan liability adjustments - prior service costs (net of tax of $2, $0 and $0, respectively) | (8) | 0 | 0 |
Reclassification adjustment of benefit plan liability - net (gain) loss (net of tax of $(166), $(22), and $(30), respectively) | (101) | 81 | 56 |
Reclassification of net realized (gains) losses on settled/amortized interest rate swaps (net of tax of $(132), $(13), and $(22), respectively) | (68) | 51 | 42 |
Other comprehensive income (loss): | |||
Other comprehensive income (loss), net of tax | (489) | 367 | 4 |
Comprehensive income | $ 46,413 | $ 46,012 | $ 51,302 |
Statements of Comprehensive I_2
Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Statement of Comprehensive Income [Abstract] | |||
Benefit plan liability adjustments - net gain (loss), Tax | $ 83 | $ (62) | $ 50 |
Benefit plan liability adjustments - prior service costs, Tax | 2 | 0 | 0 |
Reclassification adjustment of benefit plan liability - net gain (loss) tax | (166) | (22) | (30) |
Reclassification adjustment of cash flow hedges settled and included in net income (loss), Tax | $ (132) | $ (13) | $ (22) |
Balance Sheets
Balance Sheets - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 |
Current assets: | ||
Cash | $ 6 | $ 112 |
Accounts receivable, net | 25,532 | 28,431 |
Accounts receivable from affiliates | 7,838 | 8,119 |
Materials, supplies and fuel | 27,950 | 24,853 |
Regulatory assets, current | 21,588 | 19,052 |
Other current assets | 4,949 | 4,538 |
Total current assets | 87,863 | 85,105 |
Investments | 5,079 | 4,889 |
Property, plant and equipment | 1,494,670 | 1,381,045 |
Less: accumulated depreciation and amortization | (400,054) | (376,160) |
Total property, plant and equipment, net | 1,094,616 | 1,004,885 |
Other assets: | ||
Regulatory assets, non-current | 54,109 | 56,680 |
Other assets, non-current | 18,690 | 9,729 |
Total other assets, non-current | 72,799 | 66,409 |
TOTAL ASSETS | 1,260,357 | 1,161,288 |
Current liabilities: | ||
Accounts payable | 20,654 | 25,122 |
Accounts payable to affiliates | 32,121 | 25,804 |
Accrued liabilities | 25,492 | 34,193 |
Money pool notes payable | 57,585 | 38,690 |
Notes payable to Parent | 25,000 | 0 |
Regulatory liabilities, current | 3,162 | 2,574 |
Total current liabilities | 164,014 | 126,383 |
Long-term debt | 340,176 | 340,035 |
Deferred credits and other liabilities: | ||
Deferred income tax liabilities, net | 112,202 | 114,009 |
Regulatory liabilities, non-current | 163,009 | 160,642 |
Benefit plan liabilities | 14,636 | 14,606 |
Other, non-current liabilities | 15,397 | 1,368 |
Total deferred credits and other liabilities | 305,244 | 290,625 |
Commitments and contingencies (Notes 5, 12, 13 and 14) | ||
Stockholder’s equity: | ||
Common stock $1 par value; 50,000,000 shares authorized; 23,416,396 shares issued | 23,416 | 23,416 |
Additional paid-in capital | 39,575 | 39,575 |
Retained earnings | 389,312 | 342,145 |
Accumulated other comprehensive income (loss) | (1,380) | (891) |
Total stockholder’s equity | 450,923 | 404,245 |
TOTAL LIABILITIES AND STOCKHOLDER’S EQUITY | $ 1,260,357 | $ 1,161,288 |
Balance Sheets (Parenthetical)
Balance Sheets (Parenthetical) - $ / shares | Dec. 31, 2019 | Dec. 31, 2018 |
Statement of Financial Position [Abstract] | ||
Common Stock, Par Value Per Share (usd per share) | $ 1 | $ 1 |
Common Stock, Shares Authorized | 50,000,000 | 50,000,000 |
Common Stock, Shares, Issued | 23,416,396 | 23,416,396 |
Statements of Cash Flows
Statements of Cash Flows - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Operating activities: | |||
Net income | $ 46,902 | $ 45,645 | $ 51,298 |
Adjustments to reconcile net income to net cash provided by operating activities - | |||
Depreciation and amortization | 41,322 | 39,649 | 35,862 |
Deferred income taxes | (4,281) | 5,218 | 1,004 |
Employee benefits | 778 | 1,518 | 817 |
Other adjustments | 9,325 | 2,555 | 264 |
Change in operating assets and liabilities - | |||
Accounts receivable and other current assets | (933) | (3,576) | 3,287 |
Accounts payable and other current liabilities | (9,881) | (5,648) | (7,254) |
Regulatory assets | (3,290) | 27 | 978 |
Regulatory liabilities | 639 | 2,561 | 0 |
Contributions to defined benefit pension plan | (1,753) | (1,795) | (4,000) |
Other operating activities | (1,089) | (1,407) | (1,853) |
Net cash provided by operating activities | 77,739 | 84,747 | 80,403 |
Investing activities: | |||
Property, plant and equipment additions | (122,833) | (73,456) | (79,566) |
Other investing activities | 1,093 | (488) | (861) |
Net cash (used in) investing activities | (121,740) | (73,944) | (80,427) |
Financing activities: | |||
Change in money pool notes payable, net | 18,895 | (10,707) | (194) |
Notes payable to parent | 25,000 | 0 | 0 |
Net cash provided by (used in) financing activities | 43,895 | (10,707) | (194) |
Net change in cash | (106) | 96 | (218) |
Cash beginning of year | 112 | 16 | 234 |
Cash end of year | $ 6 | $ 112 | $ 16 |
Statements of Common Stockholde
Statements of Common Stockholder's Equity - USD ($) $ in Thousands | Total | Common Stock | Additional Paid-in Capital | Retained Earnings | Accumulated Other Comprehensive Income (Loss) |
Common Stock, Shares, Issued - Beginning Balance at Dec. 31, 2016 | 23,416,000 | ||||
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract] | |||||
Stock Issued During Period, Shares, New Issues | 0 | ||||
Common Stock, Shares, Issued - Ending Balance at Dec. 31, 2017 | 23,416,000 | ||||
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2016 | $ 23,416 | $ 39,575 | $ 322,933 | $ (1,262) | |
Stockholders' Equity Attributable to Parent [Abstract] | |||||
Stock Issued During Period, Value, New Issues | 0 | 0 | |||
Net income | $ 51,298 | 51,298 | |||
Non-cash Dividend to Parent Company | (42,000) | ||||
Other | 268 | ||||
Other Comprehensive Income (Loss), Net of Tax | 4 | 4 | |||
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2017 | $ 394,232 | $ 23,416 | 39,575 | 332,499 | (1,258) |
Stockholders' Equity Attributable to Parent [Abstract] | |||||
Implementation of ASU 2016-02 Leases | 0 | ||||
Stock Issued During Period, Shares, New Issues | 0 | ||||
Common Stock, Shares, Issued - Ending Balance at Dec. 31, 2018 | 23,416,396 | 23,416,000 | |||
Stockholders' Equity Attributable to Parent [Abstract] | |||||
Stock Issued During Period, Value, New Issues | $ 0 | 0 | |||
Net income | $ 45,645 | 45,645 | |||
Non-cash Dividend to Parent Company | (36,000) | ||||
Other | 1 | ||||
Other Comprehensive Income (Loss), Net of Tax | 367 | 367 | |||
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2018 | $ 404,245 | $ 23,416 | 39,575 | 342,145 | (891) |
Stockholders' Equity Attributable to Parent [Abstract] | |||||
Implementation of ASU 2016-02 Leases | 0 | ||||
Stock Issued During Period, Shares, New Issues | 0 | ||||
Common Stock, Shares, Issued - Ending Balance at Dec. 31, 2019 | 23,416,396 | 23,416,000 | |||
Stockholders' Equity Attributable to Parent [Abstract] | |||||
Stock Issued During Period, Value, New Issues | $ 0 | 0 | |||
Net income | $ 46,902 | 46,902 | |||
Non-cash Dividend to Parent Company | 0 | ||||
Other | 272 | ||||
Other Comprehensive Income (Loss), Net of Tax | (489) | (489) | |||
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2019 | $ 450,923 | $ 23,416 | $ 39,575 | 389,312 | $ (1,380) |
Stockholders' Equity Attributable to Parent [Abstract] | |||||
Implementation of ASU 2016-02 Leases | $ (7) |
Business Description and Summar
Business Description and Summary of Significant Accounting Policies: | 12 Months Ended |
Dec. 31, 2019 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Business Description and Summary of Significant Accounting Policies | BUSINESS DESCRIPTION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Business Description Black Hills Power, Inc., doing business as Black Hills Energy (“South Dakota Electric,” the “Company,” “we,” “us,” or “our”), is a regulated electric utility serving customers in Montana, South Dakota and Wyoming. We are a wholly-owned subsidiary of BHC, a public registrant listed on the New York Stock Exchange. Basis of Presentation The financial statements include the accounts of South Dakota Electric and also our ownership interests in the assets, liabilities and expenses of our jointly owned facilities ( Note 4 ) and are prepared in accordance with GAAP. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of certain assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Changes in facts and circumstances or additional information may result in revised estimates and actual results could differ materially from those estimates. Cash and Cash Equivalents We consider all highly liquid investments with an original maturity of three months or less to be cash and cash equivalents. As of December 31, 2019 and 2018 , we have no cash equivalents. Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable consists of sales to residential, commercial, industrial, municipal and other customers all of which do not bear interest. These accounts receivable are stated at billed and unbilled amounts, net of write-offs or payment received. We maintain an allowance for doubtful accounts which reflects our best estimate of uncollectible trade receivables. We regularly review our trade receivable allowances by considering such factors as historical experience, credit worthiness, the age of the receivable balances and current economic conditions that may affect collectibility. In specific cases where we are aware of a customer’s inability or reluctance to pay, we record an allowance for doubtful accounts to reduce the net receivable balance to the amount we reasonably expect to collect. However, if circumstances change, our estimate of the recoverability of accounts receivable could be affected. Circumstances which could affect our estimates include, but are not limited to, customer credit issues, the level of commodity prices, customer deposits and general economic conditions. Accounts are written off once they are deemed to be uncollectible or the time allowed for dispute under the contract has expired. Following is a summary of accounts receivable as of December 31 (in thousands): 2019 2018 Accounts receivable, trade $ 14,778 $ 16,236 Unbilled revenue 10,914 12,333 Less Allowance for doubtful accounts (160 ) (138 ) Accounts receivable, net $ 25,532 $ 28,431 Changes to allowance for doubtful accounts for the years ended December 31, were as follows (in thousands): Balance at beginning of year Additions charged to costs and expenses Deductions charged to costs and expenses Balance at end of year 2019 $ 138 $ 899 $ (877 ) $ 160 2018 $ 224 $ 911 $ (997 ) $ 138 2017 $ 157 $ 882 $ (815 ) $ 224 Materials, Supplies and Fuel Materials, supplies and fuel used for construction, operation and maintenance purposes are recorded using the weighted-average cost method. Deferred Financing Costs Deferred financing costs include loan origination fees, underwriter fees, legal fees and other costs directly attributable to the issuance of debt. Deferred financing costs are amortized over the estimated useful life of the related debt. These costs are presented on the balance sheet as an adjustment to the related debt liabilities. Regulatory Accounting Our regulated electric operations are subject to cost-of-service regulation and earnings oversight from federal and state utility commissions. We account for income and expense items in accordance with accounting standards for regulated operations: • Certain costs, which would otherwise be charged to expense or OCI, are deferred as regulatory assets based on the expected ability to recover the costs in future rates. • Certain credits, which would otherwise be reflected as income or OCI, are deferred as regulatory liabilities based on the expectation the amounts will be returned to customers in future rates, or because the amounts were collected in rates prior to the costs being incurred Management continually assesses the probability of future recoveries and obligations associated with regulatory assets and liabilities. Factors such as the current regulatory environment, recently issued rate orders, and historical precedents are considered. As a result, we believe that the accounting prescribed under rate-based regulation remains appropriate and our regulatory assets are probable of recovery in current rates or in future rate proceedings. If changes in the regulatory environment occur, we may no longer be eligible to apply this accounting treatment, and may be required to eliminate regulatory assets and liabilities from our balance sheet. Such changes could adversely affect our results of operations, financial position or cash flows. As of December 31, 2019 and 2018, we had total regulatory assets of $76 million and $76 million respectively, and total regulatory liabilities of $166 million and $163 million respectively. See Note 7 for further information. Property, Plant and Equipment Additions to property, plant and equipment are recorded at cost. Included in the cost of regulated construction projects is AFUDC, when applicable, which represents the approximate composite cost of borrowed funds and a return on equity used to finance a regulated utility project. The cost of regulated utility property, plant and equipment retired, or otherwise disposed of in the ordinary course of business, less salvage plus retirement costs, is charged to accumulated depreciation. Estimated removal costs associated with non-legal retirement obligations related to our regulated electric properties are reclassified from accumulated depreciation and reflected as regulatory liabilities. Ordinary repairs and maintenance of property, except as allowed under rate regulations, are charged to operations as incurred. Property, plant and equipment is tested for impairment when it is determined that the carrying value of the assets may not be recoverable. A loss is recognized in the current period if it becomes probable that part of a cost of a plant under construction or recently completed plant will be disallowed for recovery from customers and a reasonable estimate of the disallowance can be made. For investments in property, plant and equipment that are abandoned and not expected to go into service, incurred costs and related deferred tax amounts are compared to the discounted estimated future rate recovery, and a loss is recognized, if necessary. Depreciation provisions for regulated electric property, plant and equipment are computed on a straight-line basis using an annual composite rate of 2.2% in 2019 , 2.3% in 2018 and 2.1% in 2017 . Accrued Liabilities The following amounts by major classification are included in Accrued liabilities on the accompanying Balance Sheets as of December 31 (in thousands): 2019 2018 Accrued employee compensation, benefits and withholdings $ 4,387 $ 4,206 Accrued property taxes 6,685 6,332 Accrued income taxes 1,946 12,536 Customer deposits and prepayments 5,486 5,204 Accrued interest 4,935 4,627 Other (none of which is individually significant) 2,053 1,288 Total accrued liabilities $ 25,492 $ 34,193 Derivatives and Hedging Activities Derivatives are measured at fair value and recognized as either assets or liabilities on the Balance Sheets, except for derivative contracts that qualify for and are elected under the normal purchase and normal sales exception. Normal purchases and normal sales are contracts where physical delivery is probable, quantities are expected to be used or sold in the normal course of business over a reasonable amount of time, and price is not tied to an unrelated underlying derivative. Normal purchase and sales contracts are recognized when the underlying physical transaction is completed under the accrual basis of accounting. As part of our operations, we enter into contracts to buy and sell energy to meet the requirements of our customers. From time to time we utilize risk management contracts including interest rate swaps to fix the interest on variable rate debt, or to lock in the Treasury yield component associated with anticipated issuance of senior notes. For swaps that settled in connection with the issuance of senior debt, the effective portion is deferred as a component in AOCI and recognized as interest expense over the life of the senior note. As of December 31, 2019 , we have no outstanding interest rate swap agreements. We utilize master netting agreements which consist of an agreement between two parties who have multiple contracts with each other that provide for the net settlement of all contracts in the event of default on or termination of any one contract. When the right of offset exists, accounting standards permit the netting of receivables and payables under a legally enforceable master netting agreement between counterparties. Accounting standards also permit offsetting of fair value amounts recognized for the right to reclaim, or the obligation to return, cash collateral against fair value amounts recognized for derivative instruments executed with the same counterparty. We reflect the offsetting of net derivative positions with fair value amounts for cash collateral with the same counterpart when a legal right of offset exists. Fair Value Measurements Financial Instruments We use the following fair value hierarchy for determining inputs for our financial instruments. Our assets and liabilities for financial instruments are classified and disclosed in one of the following fair value categories: Level 1 — Unadjusted quoted prices available in active markets that are accessible at the measurement date for identical unrestricted assets or liabilities. Level 1 instruments primarily consist of highly liquid and actively traded financial instruments with quoted pricing information on an ongoing basis. Level 2 — Pricing inputs include quoted prices for identical or similar assets and liabilities in active markets other than quoted prices in Level 1, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and inputs that are derived principally from or corroborated by observable market data by correlation or other means. Level 3 — Pricing inputs are generally less observable from objective sources. These inputs reflect management’s best estimate of fair value using its own assumptions about the assumptions a market participant would use in pricing the asset or liability. Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the placement within the fair value hierarchy levels. We record transfers, if necessary, between levels at the end of the reporting period for all of our financial instruments. Transfers into Level 3, if any, occur when significant inputs used to value the derivative instruments become less observable, such as a significant decrease in the frequency and volume in which the instrument is traded, negatively impacting the availability of observable pricing inputs. Transfers out of Level 3, if any, occur when the significant inputs become more observable, such as when the time between the valuation date and the delivery date of a transaction becomes shorter, positively impacting the availability of observable pricing inputs. We currently do not have any Level 3 investments. Income Taxes We file a federal income tax return with other members of the Parent’s consolidated group. For financial statement purposes, federal income taxes are allocated to the individual companies based on amounts calculated on a separate return basis. The Company uses the asset and liability method in accounting for income taxes. Under the asset and liability method, deferred income taxes are recognized at currently enacted income tax rates, to reflect the tax effect of temporary differences between the financial and tax basis of assets and liabilities as well as operating loss and tax credit carryforwards. Such temporary differences are the result of provisions in the income tax law that either require or permit certain items to be reported on the income tax return in a different period than they are reported in the financial statements. We use the deferral method of accounting for investment tax credits as allowed by our rate-regulated jurisdictions. Such a method results in the investment tax credit being amortized as a reduction to income tax expense over the estimated useful lives of the underlying property that gave rise to the credit. We recognize interest income or interest expense and penalties related to income tax matters in Income tax expense on the Statements of Income . We account for uncertainty in income taxes recognized in the financial statements in accordance with the accounting standards for income taxes. The unrecognized tax benefit is classified in Other, non-current liabilities or in Deferred income tax liabilities, net on the accompanying Balance Sheets. See Note 9 for additional information. Recently Issued Accounting Standards Simplifying the Accounting for Income Taxes, ASU 2019-12 In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes as part of its overall simplification initiative to reduce costs and complexity in applying accounting standards while maintaining or improving the usefulness of the information provided to users of the financial statements. Amendments include removal of certain exceptions to the general principles of ASC 740, Income Taxes , and simplification in several other areas such as accounting for a franchise tax (or similar tax) that is partially based on income. The new guidance is effective for interim and annual periods beginning after December 15, 2020 with early adoption permitted. We are currently reviewing this standard to assess the impact on our financial position, results of operations and cash flows. Internal-Use Software: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, ASU 2018-15 In August 2018, the FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, which aligns the requirements for recording implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. As a result, certain categories of implementation costs that previously would have been charged to expense as incurred are now capitalized as prepayments and amortized over the term of the arrangement. The new guidance is effective for annual periods beginning after December 15, 2019, and interim periods within those fiscal years. The new guidance can be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. Early adoption is permitted. We adopted this standard prospectively on January 1, 2020. Adoption of this guidance did not have a material impact on our financial position, results of operations or cash flows. Financial Instruments -- Credit Losses: Measurement of Credit Losses on Financial Instruments, ASU 2018-19 In June 2016, the FASB issued ASU 2016-13, Financial Instruments -- Credit Losses: Measurement of Credit Losses on Financial Instruments, which was subsequently amended by ASU 2018-19, ASU 2019-04, 2019-05, 2019-10, and 2019-11. The standard introduces new accounting guidance for credit losses on financial instruments within its scope, including trade receivables. This new guidance adds an impairment model that is based on expected losses rather than incurred losses. It is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted. We adopted this standard on January 1, 2020 with prior year comparative financial information remaining as previously reported when transitioning to the new standard. On January 1, 2020, we recorded an increase to our allowance for doubtful accounts, primarily associated with the inclusion of expected losses on unbilled revenue. Adoption of this standard did not have a material impact on our financial position, results of operations or cash flows. Recently Adopted Accounting Standards Leases, ASU 2016-02 In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) , to increase transparency and comparability among organizations by requiring the recognition of right-of-use assets and lease liabilities on the balance sheet for most leases, whereas previously only financing-type lease liabilities (capital leases) were recognized on the balance sheet. Under the new standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. We adopted the standard effective January 1, 2019. We elected not to recast comparative periods coinciding with the new lease standard transition and will report these comparative periods as presented under previous lease guidance. In addition, we elected the package of practical expedients permitted under the transition guidance with the new standard, which among other things, allowed us to carry forward the historical lease classification. We also elected the practical expedient related to land easements, allowing us to carry forward our accounting treatment for existing land easements agreements. Adoption of the new standard resulted in the recording of an operating lease right-of-use asset and off-setting obligation liability of $14 million , primarily for the Wygen III ground lease, as of January 1, 2019. See Note 8 |
Revenue
Revenue | 12 Months Ended |
Dec. 31, 2019 | |
Revenue from Contract with Customer [Abstract] | |
Revenue | REVENUE Our revenue contracts generally provide for performance obligations that are fulfilled and transfer control to customers over time, represent a series of distinct services that are substantially the same, involve the same pattern of transfer to the customer, and provide a right to consideration from our customers in an amount that corresponds directly with the value to the customer for the performance completed to date. Therefore, we recognize revenue in the amount to which we have a right to invoice. Our primary types of revenue contracts are: • Regulated electric utility services tariffs - Our regulated operations, as defined by ASC 980, provide services to regulated customers under tariff rates, charges, terms and conditions of service, and prices determined by the jurisdictional regulators designated for our service territories. Our regulated services primarily encompass single performance obligations for delivery of commodity electricity and electric transmission services. These service revenues are variable based on quantities delivered, influenced by seasonal business and weather patterns. Tariffs are only permitted to be changed through a rate-setting process involving the state or federal regulatory commissions to establish contractual rates between the utility and its customers. All of our regulated utility sales are subject to regulatory-approved tariffs. • Power sales agreements - We have long-term wholesale power sales agreements with other load serving entities for the sale of excess power from owned generating units. In addition to these long-term contracts, the Company also sells excess energy to other load-serving entities on a short-term basis. The pricing for all of these arrangements is included in the executed contracts or confirmations, reflecting the standalone selling price, and is variable based on energy delivered. The following table depicts the disaggregation of revenue, including intercompany revenue, from contracts with customers by customer type and timing of revenue recognition. Sales tax and other similar taxes are excluded from revenues. Year ended December 31, 2019 Year ended December 31, 2018 (in thousands) Customer types: Retail $ 202,569 $ 197,184 Wholesale 19,078 33,687 Market - off-system sales 16,475 17,691 Transmission/Other 50,329 49,015 Revenue from contracts with customers 288,451 297,577 Other revenues 2,768 503 Total revenues $ 291,219 $ 298,080 Timing of revenue recognition: Services transferred over time $ 288,451 $ 297,577 Revenue from contracts with customers $ 288,451 $ 297,577 The majority of our revenue contracts are based on variable quantities delivered; any fixed consideration contracts with an expected duration of one year or more are immaterial to our revenues. Variable consideration constraints in the form of discounts, rebates, credits, price concessions, incentives, performance bonuses, penalties or other similar items are not material for our revenue contracts. We are the principal in our revenue contracts, as we have control over the services prior to those services being transferred to the customer. Revenue Not in Scope of ASC 606 Other revenues included in the table above include revenue accounted for under separate accounting guidance, including alternative revenue programs revenue under ASC 980. Significant Judgments and Estimates Unbilled Revenue To the extent that deliveries have occurred but a bill has not been issued, the Company accrues an estimate of the revenue since the latest billing. This estimate is calculated based on several factors including billings through the last billing cycle in a month and prices in effect in our jurisdictions. Each month the estimated unbilled revenue amounts are trued-up and recorded in Accounts receivable, net on the accompanying Balance Sheets. Contract Balances The nature of our primary revenue contracts provides an unconditional right to consideration upon service delivery; therefore, no customer contract assets or liabilities exist. The unconditional right to consideration is represented by the balance in our Accounts Receivable and is further discussed above. We do not typically incur costs that would be capitalized, to obtain or fulfill a contract. |
Property, Plant and Equipment
Property, Plant and Equipment | 12 Months Ended |
Dec. 31, 2019 | |
Property, Plant and Equipment [Abstract] | |
Property, Plant and Equipment | PROPERTY, PLANT AND EQUIPMENT Property, plant and equipment at December 31 consisted of the following (dollars in thousands): 2019 2018 Weighted Weighted Average Average 2019 Useful Life (in years) 2018 Useful Life (in years) Property, plant, and equipment: Production $ 612,517 46 $ 588,565 46 Transmission 235,390 51 208,610 48 Distribution 431,783 46 394,475 45 Plant acquisition adjustment (a) 4,870 32 4,870 32 General 165,342 29 154,621 28 Total plant-in-service 1,449,902 1,351,141 Construction work in progress 44,768 29,904 Total property, plant and equipment 1,494,670 1,381,045 Less accumulated depreciation and amortization (400,054 ) (376,160 ) Total property, plant and equipment, net $ 1,094,616 $ 1,004,885 __________________ (a) The plant acquisition adjustment is included in rate base and is being recovered with 11 years remaining. |
Jointly Owned Facilities
Jointly Owned Facilities | 12 Months Ended |
Dec. 31, 2019 | |
Jointly Owned Utility Plant, Net Ownership Amount [Abstract] | |
Jointly Owned Facilities | JOINTLY OWNED FACILITIES Our financial statements include our share of several jointly-owned utility facilities as described below. Our share of the facilities’ expenses is reflected in the appropriate categories of operating expenses in the Statements of Income. Each owner of the facility is responsible for financing its investment in the jointly-owned facilities. • We own a 20% interest in the Wyodak Plant (the “Plant”), a coal-fired electric generating station located in Campbell County, Wyoming. PacifiCorp owns the remaining ownership percentage and is the operator of the Plant. We receive our proportionate share of the Plant’s capacity and are committed to pay our share of its additions, replacements and operating and maintenance expenses. • We own a 35% interest in, and are the operator of, the Converter Station Site and South Rapid City Interconnection (the transmission tie), an AC-DC-AC transmission tie. Basin Electric owns the remaining ownership percentage. The transmission tie provides an interconnection between the Western and Eastern transmission grids, which provides us with access to both the WECC region and the SPP region. The total transfer capacity of the transmission tie is 400 MW, including 200 MW West to East and 200 MW from East to West. We are committed to pay our proportionate share of the additions, replacements and operating and maintenance expenses. • We own a 52% interest in the Wygen III power plant. MDU and the City of Gillette each owns an undivided ownership interest in Wygen III and are obligated to make payments for costs associated with administrative services and a proportionate share of the costs of operating the plant for the life of the facility. We retain responsibility for plant operations. • We own 55 MW of the Cheyenne Prairie combined cycle, a 95 MW gas-fired power generation facility located in Cheyenne, Wyoming. Wyoming Electric owns the remaining 40 MW. We are committed to pay our proportionate share of the additions, replacements and operating and maintenance expenses. As of December 31, 2019 , our interests in jointly-owned generating facilities and transmission systems were (in thousands): Interest in jointly-owned facilities Plant in Service Construction Work in Progress Less Accumulated Depreciation Plant Net of Accumulated Depreciation Wyodak Plant $ 116,074 $ 729 $ (64,413 ) $ 52,390 Transmission Tie $ 19,862 $ 4,161 $ (6,612 ) $ 17,411 Wygen III $ 146,161 $ 400 $ (25,518 ) $ 121,043 Cheyenne Prairie $ 92,684 $ 532 $ (14,202 ) $ 79,014 |
Long term Debt
Long term Debt | 12 Months Ended |
Dec. 31, 2019 | |
Long-term Debt, Unclassified [Abstract] | |
Long-term Debt | LONG-TERM DEBT Long-term debt outstanding at December 31 was as follows (in thousands): Interest Rate at Balance Outstanding Due Date December 31, 2019 December 31, 2019 December 31, 2018 First Mortgage Bonds due 2032 August 15, 2032 7.23 % 75,000 75,000 First Mortgage Bonds due 2039 November 1, 2039 6.13 % 180,000 180,000 First Mortgage Bonds due 2044 October 20, 2044 4.43 % 85,000 85,000 Series 94A Debt (a) June 1, 2024 1.84 % 2,855 2,855 Less unamortized debt discount (82 ) (86 ) Less unamortized deferred financing costs (2,597 ) (2,734 ) Long-term Debt, net 340,176 340,035 ___________________ (a) Variable interest rate at December 31, 2019 . Net deferred financing costs of approximately $2.6 million and $2.7 million were recorded on the accompanying Balance Sheets in long-term debt at December 31, 2019 and 2018 , respectively, and are being amortized over the term of the debt. Amortization of deferred financing costs of approximately $0.1 million for each of the years ended December 31, 2019 , 2018 and 2017 are included in Interest expense on the accompanying Statements of Income . Substantially all of our property is subject to the lien of the indenture securing our first mortgage bonds. First mortgage bonds may be issued in amounts limited by property, earnings and other provisions of the mortgage indentures. We were in compliance with our debt covenants at December 31, 2019 . Long-term Debt Maturities Scheduled maturities of our outstanding long-term debt (excluding unamortized discounts and unamortized deferred financing costs) are as follows (in thousands): 2020 $ — 2021 $ — 2022 $ — 2023 $ — 2024 $ 2,855 Thereafter $ 340,000 |
Fair Value of Financial Instrum
Fair Value of Financial Instruments: Fair Value of Financial Instruments | 12 Months Ended |
Dec. 31, 2019 | |
Fair Value Disclosures [Abstract] | |
Fair Value of Financial Instruments | FAIR VALUE OF FINANCIAL INSTRUMENTS The estimated fair values of our financial instruments at December 31 were as follows (in thousands): 2019 2018 Carrying Value Fair Value Carrying Value Fair Value Cash (a) $ 6 $ 6 $ 112 $ 112 Notes payable to Parent (b) $ 25,000 $ 25,000 $ — $ — Long-term debt (c) $ 340,176 $ 458,286 $ 340,035 $ 412,894 _______________ (a) The cash fair value approximates carrying value and therefore is classified as Level 1 in the fair value hierarchy. We believe that the market risk arising from cash in a bank account is minimal. (b) Carrying value approximates fair value due to the short-term length of maturity; since these borrowings are not traded on an exchange, they are classified in Level 2 in the fair value hierarchy. (c) Long-term debt is valued based on observable inputs available either directly or indirectly for similar liabilities in active markets and therefore is classified as Level 2 in the fair value hierarchy. Carrying amount of long-term debt is net of deferred financing costs. Notes payable to Parent For additional information on our Notes payable to Parent, see Note 14 . Long-Term Debt For additional information on our long-term debt, see Note 5 . |
Regulatory Matters
Regulatory Matters | 12 Months Ended |
Dec. 31, 2019 | |
Regulated Operations [Abstract] | |
Regulatory Matters | REGULATORY MATTERS We had the following regulatory assets and liabilities as of December 31 (in thousands): 2019 2018 Regulatory assets Loss on reacquired debt (a) $ 989 $ 1,259 Deferred taxes on AFUDC (b) 4,927 5,020 Employee benefit plans and related deferred taxes (c) 20,661 19,868 Deferred energy and fuel cost adjustments (a) 23,203 20,334 Deferred taxes on flow through accounting (c) 9,801 8,749 Decommissioning costs (b) 6,211 8,196 Vegetation management (a) 8,062 10,366 Other regulatory assets (a) 1,843 1,940 Total regulatory assets 75,697 75,732 Less current regulatory assets (21,588 ) (19,052 ) Regulatory assets, non-current $ 54,109 $ 56,680 Regulatory liabilities Cost of removal for utility plant (a) $ 57,318 $ 52,366 Employee benefit plans and related deferred taxes (c) 7,023 7,518 Excess deferred income taxes (c) 98,228 100,276 TCJA revenue reserve 3,162 2,523 Other regulatory liabilities (c) 440 533 Total regulatory liabilities 166,171 163,216 Less current regulatory liabilities (3,162 ) (2,574 ) Regulatory liabilities, non-current $ 163,009 $ 160,642 ____________________ (a) We are allowed a recovery of costs but we are not allowed a rate of return. (b) In addition to recovery of costs, we are allowed a rate of return. (c) In addition to recovery or repayment of costs, we are allowed a return on a portion of this amount or a reduction in rate base. Regulatory assets represent items we expect to recover from customers through probable future increases in rates. Loss on Reacquired Debt - Loss on reacquired debt is recovered over the remaining life of the original issue or, if refinanced, over the life of the new issue. Deferred Taxes on AFUDC - The equity component of AFUDC is considered a permanent difference for tax purposes with the tax benefit being flowed through to customers as prescribed or allowed by regulators. If, based on a regulator’s action, it is probable the utility will recover the future increase in taxes payable represented by this flow-through treatment through a rate revenue increase, a regulatory asset is recognized. This regulatory asset itself is a temporary difference for which a deferred tax liability must be recognized. Accounting standards for income taxes specifically address AFUDC-equity, and require a gross-up of such amounts to reflect the revenue requirement associated with a rate-regulated environment. Employee Benefit Plans - Employee benefit plans include the unrecognized prior service costs and net actuarial loss associated with our defined benefit pension plan and other post-retirement benefit plans in regulatory assets rather than in accumulated other comprehensive income. In addition, this regulatory asset includes the income tax effect of the adjustment required under accounting for compensation-defined benefit plans to record the full pension and post-retirement benefit obligations. Deferred Energy and Fuel Cost Adjustments - Deferred energy and fuel cost adjustments represent the cost of electricity delivered to our customers that is either higher or lower than the current rates and will be recovered or refunded in future rates. Deferred energy and fuel cost adjustments are recorded and recovered or amortized as approved by the appropriate state commission. We file periodic quarterly, semi-annual and/or annual filings to recover these costs based on the respective cost mechanisms approved by the applicable state utility commissions. Deferred Taxes on Flow-Through Accounting - Under flow-through accounting, the income tax effects of certain tax items are reflected in our cost of service for the customer in the year in which the tax benefits are realized and result in lower utility rates. A regulatory asset was established to reflect that future increases in income taxes payable will be recovered from customers as the temporary differences reverse. As a result of this regulatory treatment, we continue to record a tax benefit for costs considered currently deductible for tax purposes, but are capitalized for book purposes. Decommissioning Costs - We received approval in 2014 for regulatory treatment on the remaining net book values and decommissioning costs of our decommissioned coal plants. Vegetation Management Costs - We received approval in 2013 for regulatory treatment on vegetation management maintenance costs for our distribution system rights-of-way. Regulatory liabilities represent items we expect to refund to customers through probable future decreases in rates. Cost of Removal for Utility Plant - Cost of removal for utility plant represents the estimated cumulative net provisions for future removal costs included in depreciation expense for which there is no legal obligation for removal. Employee Benefit Plans - Employee benefit plans represent the cumulative excess of pension and other postretirement benefit costs recovered in rates over pension expense recorded in accordance with accounting standards for compensation-retirement benefits. In addition, this regulatory liability includes the income tax effect of the adjustment required under accounting for compensation-defined benefit plans, to record the full pension and post-retirement benefit obligations. Excess Deferred Income Taxes - The revaluation of our deferred tax assets and liabilities due to the passage of the TCJA is recorded as an excess deferred income tax to be refunded to customers primarily using the normalization principles as prescribed in the TCJA. See Note 9 for additional information. TCJA Revenue Reserve - Revenue to be returned to customers as a result of the TCJA. See Note 9 for additional information. Regulatory Matters Settlement On January 7, 2020, South Dakota Electric received approval from the SDPUC on a settlement agreement to extend the 6 -year moratorium period by an additional 3 years to June 30, 2026. Also, as part of the settlement, we withdrew our application for deferred accounting treatment and expensed $5.4 million of development costs related to projects we no longer intend to construct. This settlement amends a previous agreement approved by the SDPUC on June 16, 2017, whereby South Dakota Electric would not increase base rates, absent an extraordinary event, for a 6 year moratorium period effective July 1, 2017. The moratorium period also includes suspension of both the TFA and EIA. Renewable Ready In July 2019, South Dakota Electric and Wyoming Electric received approvals for the Renewable Ready program and related jointly-filed CPCN to construct Corriedale. The wind project will be jointly owned by the two electric utilities to deliver renewable energy for large commercial, industrial and governmental agency customers. In November 2019, South Dakota Electric received approval from the SDPUC to increase the offering under the program by 12.5 MW to 32.5 MW. The two electric utilities also received a determination from the WPSC that the wind project can be increased to 52.5 MW. The $ 79 million project is expected to be in service by year-end 2020. FERC Formula Rate The annual rate determination process is governed by the FERC formula rate protocols established in the filed FERC joint-access transmission tariff. Effective January 1, 2019 the annual revenue requirement increased by $1.9 million and included estimated weighted average capital additions of $31 million |
Leases
Leases | 12 Months Ended |
Dec. 31, 2019 | |
Leases [Abstract] | |
Leases | LEASES We have a ground lease for the Wygen III generating facility with an affiliate and communication tower site and operation center facility leases with third parties. Our leases have remaining terms ranging from 1 year to 30 years . The components of lease expense were as follows (in thousands): Income Statement Location For the year ended December 31, 2019 Operating lease cost Operations and maintenance $ 908 Variable lease cost Operations and maintenance 137 Total lease cost $ 1,045 Supplemental balance sheet information related to leases was as follows (in thousands): Balance Sheet Location As of December 31, 2019 Assets: Operating lease assets Other assets, non-current $ 14,374 Total lease assets $ 14,374 Liabilities: Current: Operating leases Accrued liabilities $ 293 Noncurrent: Operating leases Other deferred credits and other liabilities 14,105 Total lease liabilities $ 14,398 Supplemental cash flow information related to leases was as follows (in thousands): For the year ended December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 912 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ — As of December 31, 2019 Weighted average remaining lease term (years): Operating leases 30 years Weighted average discount rate: Operating leases 4.3 % Scheduled maturities of operating lease liabilities for future years were as follows (in thousands): Total 2020 $ 912 2021 911 2022 911 2023 908 2024 906 Thereafter 21,128 Total lease payments 25,676 Less imputed interest 11,278 Present value of lease liabilities $ 14,398 As previously disclosed in Note 11 of the Notes to the Financial Statements in our 2018 Annual Report on Form 10-K, prior to the adoption of ASU 2016-02, Leases (Topic 842), the future minimum payments required under operating lease agreements as of December 31, 2018 were as follows (in thousands): Operating Leases 2019 $ 911 2020 856 2021 855 2022 856 2023 853 Thereafter 21,947 Total lease payments $ 26,278 |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2019 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | INCOME TAXES On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the TCJA. The TCJA reduced the U.S. federal corporate tax rate from 35% to 21% . As such, the Company has remeasured the deferred income taxes at the 21% federal tax rate as of December 31, 2017. As a result of the revaluation at December 31, 2017, deferred tax assets and liabilities were reduced by approximately $103 million . Of the $103 million , approximately $101 million was ultimately reclassified to a regulatory liability. As of December 31, 2019 we have a regulatory liability associated with TCJA related items of $98 million . A significant portion of the excess deferred taxes are subject to the average rate assumption method, as prescribed by the IRS, and will generally be amortized as a reduction of customer rates over the remaining lives of the related assets. As of December 31, 2019 , the Company has amortized $3.1 million of this regulatory liability. Income tax expense for the years ended December 31 was as follows (in thousands): 2019 2018 2017 Current: Federal $ 13,782 $ 5,454 $ 13,124 Deferred: Federal (4,281 ) 5,218 1,004 Total income tax expense $ 9,501 $ 10,672 $ 14,128 The temporary differences, which gave rise to the net deferred tax liability, for the years ended December 31 were as follows (in thousands): 2019 2018 Deferred tax assets: Regulatory liabilities $ 25,623 $ 25,587 Other 9,128 4,721 Total deferred tax assets 34,751 30,308 Deferred tax liabilities: Accelerated depreciation and other plant related differences (125,138 ) (125,594 ) Regulatory assets (7,193 ) (7,147 ) Deferred costs (8,264 ) (8,572 ) Other (6,358 ) (3,004 ) Total deferred tax liabilities (146,953 ) (144,317 ) Net deferred tax liability $ (112,202 ) $ (114,009 ) The effective tax rate differs from the federal statutory rate for the years ended December 31, as follows: 2019 2018 2017 Federal statutory rate 21.0% 21.0% 35.0% Amortization of excess deferred and investment tax credits (3.0) (1.3) (0.1) Flow-through adjustments (a) (1.5) (1.7) (1.8) TCJA corporate rate reduction (b) — 2.5 (9.2) Other 0.3 (1.6) (2.3) 16.8% 18.9% 21.6% _________________________ (a) Flow-through adjustments related primarily to an accounting method for tax purposes that allows us to take a current tax deduction for repair costs. We recorded a deferred income tax liability in recognition of the temporary difference created between book and tax treatment and we flowed the tax benefit through to tax expense. (b) On December 22, 2017, the TCJA was signed into law reducing the federal corporate rate from 35% to 21% , effective January 1, 2018. The 2017 effective tax rate reduction reflects the revaluation of deferred income taxes required by the change. During the year ended December 31, 2018, we recorded approximately $0.9 million of additional tax expense associated with changes in the prior estimated impacts of TCJA related items. The following table reconciles the total amounts of unrecognized tax benefits, without interest, included in Other deferred credits and other liabilities on the accompanying Balance Sheet (in thousands): 2019 2018 Unrecognized tax benefits at January 1 $ 249 $ 302 Additions for current year tax positions — — Additions for prior year tax positions — 2 Reductions for prior year tax positions (33 ) (55 ) Unrecognized tax benefits at December 31 $ 216 $ 249 The total amount of unrecognized tax benefits that, if recognized, would impact the effective tax rate is not material to the financial results of the Company. It is the Company’s continuing practice to recognize interest and/or penalties related to income tax matters in income tax expense. During the years ended December 31, 2019 and 2018 , the interest expense recognized was not material to the financial results of the Company. We do not anticipate that total unrecognized tax benefits will significantly change due to the settlement of any audits or the expiration of statutes of limitations on or before December 31, 2020 . We file income tax returns in the United States federal jurisdictions as a member of the BHC consolidated group. |
Comprehensive Income
Comprehensive Income | 12 Months Ended |
Dec. 31, 2019 | |
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] | |
Comprehensive Income | OTHER COMPREHENSIVE INCOME We record deferred gains (losses) in AOCI related to interest rate swaps designated as cash flow hedges and the amortization of components of our defined benefit plans. Deferred gains (losses) related to our interest rate swaps are recognized in earnings as they are amortized. The following table details reclassifications out of AOCI and into net income. The amounts in parentheses below indicate decreases to net income in the Statements of Income for the period, net of tax (in thousands): Location on the Statements of Income Amounts Reclassified from AOCI December 31, 2019 December 31, 2018 Gains and (losses) on cash flow hedges: Interest rate swaps Interest expense $ (64 ) $ (64 ) Income tax Income tax benefit (expense) 132 13 Total reclassification adjustments related to cash flow hedges, net of tax $ 68 $ (51 ) Amortization of components of defined benefit plans: Actuarial gain (loss) Operations and maintenance $ (65 ) $ (103 ) Income tax Income tax benefit (expense) 166 22 Total reclassification adjustments related to defined benefit plans, net of tax $ 101 $ (81 ) Derivatives designated as cash flow hedges relate to a treasury lock entered into in August 2002 to hedge $50 million of our First Mortgage Bonds due on August 15, 2032 . The treasury lock cash settled on August 8, 2002, the bond pricing date, and resulted in a $1.8 million loss. The treasury lock is treated as a cash flow hedge and the resulting loss is carried in Accumulated other comprehensive loss and is being amortized over the life of the related bonds. Balances by classification included within AOCI, net of tax, on the accompanying Balance Sheets were as follows (in thousands): Derivatives Designated as Cash Flow Hedges Interest Rate Swaps Employee Benefit Plans Total As of December 31, 2018 $ (500 ) $ (391 ) $ (891 ) Other comprehensive income (loss) before reclassifications — (320 ) (320 ) Amounts reclassified from AOCI (68 ) (101 ) (169 ) As of December 31, 2019 $ (568 ) $ (812 ) $ (1,380 ) Derivatives Designated as Cash Flow Hedges Interest Rate Swaps Employee Benefit Plans Total As of December 31, 2017 $ (551 ) $ (707 ) $ (1,258 ) Other comprehensive income (loss) before reclassifications — 235 235 Amounts reclassified from AOCI 51 81 132 As of December 31, 2018 $ (500 ) $ (391 ) $ (891 ) |
Supplemental Cash Flow Informat
Supplemental Cash Flow Information | 12 Months Ended |
Dec. 31, 2019 | |
Supplemental Cash Flow Information [Abstract] | |
Supplemental Cash Flow Information | SUPPLEMENTAL CASH FLOW INFORMATION Years ended December 31, 2019 2018 2017 (in thousands) Non-cash investing and financing activities - Accrued property, plant and equipment purchases at December 31 $ 12,305 $ 15,180 $ 6,565 Non-cash decrease to money pool note receivable, net $ — $ (36,000 ) $ (42,000 ) Non-cash dividend to Parent $ — $ 36,000 $ 42,000 Cash (paid) refunded during the period for - Interest (net of amounts capitalized) $ (21,909 ) $ (21,988 ) $ (21,517 ) Income taxes (paid), net $ (24,372 ) $ (10,394 ) $ (12,719 ) |
Employee Benefit Plans
Employee Benefit Plans | 12 Months Ended |
Dec. 31, 2019 | |
Defined Benefit Plan [Abstract] | |
Employee Benefit Plans | EMPLOYEE BENEFIT PLANS Defined Contribution Plans BHC sponsors a 401(k) retirement savings plan (the 401(k) Plan). Participants in the 401(k) Plan may elect to invest a portion of their eligible compensation to the 401(k) Plan up to the maximum amounts established by the IRS. The 401(k) Plan provides employees the opportunity to invest up to 50% of their eligible compensation on a pre-tax or after-tax basis. The 401(k) Plan provides a Company matching contribution for all eligible participants. Certain eligible participants who are not currently accruing a benefit in the Pension Plan also receive a Company retirement contribution based on the participant’s age and years of service. Vesting of all Company and matching contributions occurs at 20% per year with 100% vesting when the participant has 5 years of service with the Company. Defined Benefit Pension Plan We have one defined benefit pension plan, the Black Hills Retirement Plan (Pension Plan). The Pension Plan covers certain eligible employees of the Company. The benefits for the Pension Plan are based on years of service and calculations of average earnings during a specific time period prior to retirement. The Pension Plan is closed to new employees and frozen for certain employees who did not meet age and service based criteria. The Pension Plan assets are held in a Master Trust. Our Board of Directors has approved the Pension Plan’s investment policy. The objective of the investment policy is to manage assets in such a way that will allow the eventual settlement of our obligations to the Pension Plan’s beneficiaries. To meet this objective, our pension assets are managed by an outside adviser using a portfolio strategy that will provide liquidity to meet the Pension Plan’s benefit payment obligations. The Pension Plan’s assets consist primarily of equity, fixed income and hedged investments. The expected rate of return on the Pension Plan assets is determined by reviewing the historical and expected returns of both equity and fixed income markets, taking into account asset allocation, the correlation between asset class returns, and the mix of active and passive investments. The Pension Plan utilizes a dynamic asset allocation where the target allocation range to return-seeking and liability-hedging assets is determined based on the funded status of the Plan. As of December 31, 2019 , the expected rate of return on pension plan assets is based on the targeted asset allocation range of 29% to 37% return-seeking assets and 63% to 71% liability-hedging assets. Our Pension Plan is funded in compliance with the federal government’s funding requirements. Plan Assets The percentages of total plan asset by investment category of our Pension Plan assets at December 31 were as follows: 2019 2018 Equity securities 20 % 17 % Real estate 3 4 Fixed income funds 71 71 Cash and cash equivalents 2 3 Hedge funds 4 5 Total 100 % 100 % Supplemental Non-qualified Defined Benefit Plans We have various supplemental retirement plans for key executives of the Company. The plans are non-qualified defined benefit and defined contribution plans (Supplemental Plans). The Supplemental Plans are subject to various vesting schedules and are funded on a cash basis as benefits are paid. Non-pension Defined Benefit Postretirement Healthcare Plan BHC sponsors a retiree healthcare plan (Healthcare Plan) for employees who meet certain age and service requirements at retirement. Healthcare Plan benefits are subject to premiums, deductibles, co-payment provisions and other limitations. Pre-65 retirees receive their retiree medical benefits through the Black Hills self-insured retiree medical plan. Healthcare coverage for Medicare-eligible BHP retirees is provided through an individual market healthcare exchange. Plan Assets We fund our Healthcare Plan on a cash basis as benefits are paid. Plan Contributions Contributions to the Pension Plan are cash contributions made directly to the Master Trust. Healthcare benefits include company and participant paid premiums. Contributions for the years ended December 31 were as follows (in thousands): 2019 2018 Defined Contribution Plan Company retirement contributions $ 888 $ 876 Company matching contributions $ 1,275 $ 1,272 2019 2018 Defined Benefit Plans Defined Benefit Pension Plan $ 1,753 $ 1,795 Non-Pension Defined Benefit Postretirement Healthcare Plan $ 739 $ 388 Supplemental Non-qualified Defined Benefit Plans $ 266 $ 238 While we do not have required contributions, we expect to make approximately $1.7 million in contributions to our Pension Plan in 2020 . Fair Value Measurements Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect their placement within the fair value hierarchy levels. The following tables set forth, by level within the fair value hierarchy, the assets that were accounted for at fair value on a recurring basis (in thousands): Pension Plan December 31, 2019 Level 1 Level 2 Level 3 Total Investments Measured at Fair Value NAV (a) Total Investments AXA Equitable General Fixed Income $ — $ 8 $ — $ 8 $ — $ 8 Common Collective Trust - Cash and Cash Equivalents — 978 — 978 — 978 Common Collective Trust - Equity — 12,072 — 12,072 — 12,072 Common Collective Trust - Fixed Income — 42,449 — 42,449 — 42,449 Common Collective Trust - Real Estate — — — — 1,974 1,974 Hedge Funds — — — — 2,709 2,709 Total investments measured at fair value $ — $ 55,507 $ — $ 55,507 $ 4,683 $ 60,190 Pension Plan December 31, 2018 Level 1 Level 2 Level 3 Total Investments Measured at Fair Value NAV (a) Total Investments AXA Equitable General Fixed Income $ — $ 261 $ — $ 261 $ — $ 261 Common Collective Trust - Cash and Cash Equivalents — 1,388 — 1,388 — 1,388 Common Collective Trust - Equity — 9,436 — 9,436 — 9,436 Common Collective Trust - Fixed Income — 39,047 — 39,047 — 39,047 Common Collective Trust - Real Estate — 9 — 9 1,896 1,905 Hedge Funds — — — — 2,627 2,627 Total investments measured at fair value $ — $ 50,141 $ — $ 50,141 $ 4,523 $ 54,664 ________________________ (a) Certain investments that are measured at fair value using NAV per share (or its equivalent) for practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in these tables for these investments are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the reconciliation of changes in the plan’s benefit obligations and fair value of plan assets above. AXA Equitable General Fixed Income Fund : This fund is a diversified portfolio, primarily composed of fixed income instruments. Assets are invested in long-term holdings, such as commercial, agricultural and residential mortgages, publicly traded and privately placed bonds and real estate as well as short-term bonds. Fair values of mortgage loans are measured by discounting future contractual cash flows to be received on the mortgage loans using interest rates of loans with similar characteristics. The discount rate is derived from taking the appropriate U.S. Treasury rate with a like term. The fair value of public fixed maturity securities are generally based on prices obtained from independent valuation service providers with reasonableness prices compared with directly observable market trades. The fair value of privately placed securities are determined using a discounted cash flow model. These models use observable inputs with a discount rate based upon the average of spread surveys collected from private market intermediaries and industry sector of the issuer. The Plan’s investments in the AXA Equitable General Fixed Income Fund are categorized as Level 2. Common Collective Trust Funds: These funds are valued based upon the redemption price of units held by the Plan, which is based on the current fair value of the common collective trust funds’ underlying assets. Unit values are determined by the financial institution sponsoring such funds by dividing the fund’s net assets at fair value by its units outstanding at the valuation dates. The Plan’s investments in common collective trust funds, with the exception of shares of the common collective trust-real estate are categorized as Level 2. Common Collective Trust-Real Estate Fund : This fund is valued based on various factors of the underlying real estate properties, including market rent, market rent growth, occupancy levels, etc. As part of the trustee’s valuation process, properties are externally appraised generally on an annual basis. The appraisals are conducted by reputable independent appraisal firms and signed by appraisers that are members of the Appraisal Institute, with professional designation of Member, Appraisal Institute. All external appraisals are performed in accordance with the Uniform Standards of Professional Appraisal Practices. We receive monthly statements from the trustee, along with the annual schedule of investments and rely on these reports for pricing the units of the fund. Some of the funds without participant withdrawal limitations are categorized as Level 2. The following investments are measured at NAV and are not classified in the fair value hierarchy, in accordance with accounting guidance: Common Collective Trust-Real Estate Fund : This is the same fund as above except that certain of the funds’ assets contain participant withdrawal policies with restrictions on redemption and are therefore not included in the fair value hierarchy. Hedge Funds: These funds represent investments in other investment funds that seek a return utilizing a number of diverse investment strategies. The strategies, when combined, aim to reduce volatility and risk while attempting to deliver positive returns under all market conditions. Amounts are reported on a one-month lag. The fair value of hedge funds is determined using net asset value per share based on the fair value of the hedge fund’s underlying investments. 20% of the shares may be redeemed at the end of each month with a 10 -day notice and full redemptions are available at the end of each quarter with 30 -day notice and is limited to a percentage of the total net assets value of the fund. The net asset values are based on the fair value of each fund’s underlying investments. There are no unfunded commitments related to these hedge funds. Other Plan Information The following tables provide a reconciliation of the employee benefit plan obligations, fair value of assets and amounts recognized in the Balance Sheets, components of the net periodic expense and elements of AOCI: Benefit Obligations Defined Benefit Pension Plan Supplemental Non-qualified Defined Benefit Plans Non-pension Defined Benefit Postretirement Healthcare Plan As of December 31 (in thousands) 2019 2018 2019 2018 2019 2018 Change in benefit obligation: Projected benefit obligation at beginning of year $ 61,919 $ 67,562 $ 2,992 $ 3,418 $ 5,055 $ 5,970 Service cost 365 516 — — 148 193 Interest cost 2,410 2,194 114 108 186 179 Actuarial loss (gain) 7,482 (2,878 ) 406 (296 ) 507 (889 ) Benefits paid (5,234 ) (3,562 ) (266 ) (238 ) (739 ) (389 ) Plan participants transfer to affiliate 119 (1,913 ) — — (77 ) (129 ) Plan participants’ contributions — — — — 96 120 Projected benefit obligation at end of year $ 67,061 $ 61,919 $ 3,246 $ 2,992 $ 5,176 $ 5,055 Employee Benefit Plan Assets Defined Benefit Pension Plan Supplemental Non-qualified Defined Benefit Plans Non-pension Defined Benefit Postretirement Healthcare Plan As of December 31 (in thousands) 2019 2018 2019 2018 2019 2018 Beginning fair value of plan assets $ 54,664 $ 59,884 $ — $ — $ — $ — Investment income (loss) 8,902 (1,884 ) — — — — Employer contributions 1,753 1,795 266 238 643 268 Retiree contributions — — — — 96 120 Benefits paid (5,234 ) (3,563 ) (266 ) (238 ) (739 ) (388 ) Plan participants transfer to affiliate 105 (1,568 ) — — — — Ending fair value of plan assets $ 60,190 $ 54,664 $ — $ — $ — $ — The funded status of the plans and amounts recognized in the Balance Sheets at December 31 consist of (in thousands): Defined Benefit Pension Plan Supplemental Non-qualified Defined Benefit Plans Non-pension Defined Benefit Postretirement Healthcare Plan 2019 2018 2019 2018 2019 2018 Regulatory asset $ 20,117 $ 19,099 $ — $ — $ — $ — Current liability $ — $ — $ 321 $ 230 $ 586 $ 466 Non-current liability $ 7,121 $ 7,255 $ 2,925 $ 2,762 $ 4,590 $ 4,589 Regulatory liability $ — $ — $ — $ — $ 1,675 $ 2,441 Accumulated Benefit Obligation Defined Benefit Pension Plan Supplemental Non-pension Defined Benefit Postretirement Healthcare Plan As of December 31 (in thousands) 2019 2018 2019 2018 2019 2018 Accumulated benefit obligation $ 65,225 $ 59,987 $ 3,246 $ 2,992 $ 5,176 $ 5,055 Components of Net Periodic Expense Net periodic expense consisted of the following for the year ended December 31 (in thousands): Defined Benefit Pension Plan Supplemental Non-pension Defined Benefit Postretirement Healthcare Plan 2019 2018 2017 2019 2018 2017 2019 2018 2017 Service cost $ 365 $ 516 $ 545 $ — $ — $ — $ 148 $ 193 $ 206 Interest cost 2,410 2,194 2,341 114 108 116 186 179 176 Expected return on assets (3,405 ) (3,545 ) (3,591 ) — — — — — — Amortization of prior service cost (credits) 10 43 43 — — — (336 ) (336 ) (336 ) Recognized net actuarial loss (gain) 1,221 2,063 1,230 65 103 87 — — — Net periodic expense $ 601 $ 1,271 $ 568 $ 179 $ 211 $ 203 $ (2 ) $ 36 $ 46 For the years ended December 31, 2019 and 2018, service costs were recorded in Operations and maintenance expense while non-service costs were recorded in Other expense, on the Statements of Income. For the year ended December 31, 2017, service costs and non-service costs were recorded in Operations and maintenance expense. Because prior years’ costs were not considered material, they were not reclassified on the Statements of Income. AOCI For defined benefit plans, amounts included in AOCI, after-tax, that have not yet been recognized as components of net periodic benefit cost at December 31 were as follows (in thousands): Defined Benefit Pension Plan Supplemental Non-qualified Defined Benefit Plans Non-pension Defined Benefit Postretirement Healthcare Plan 2019 2018 2019 2018 2019 2018 Net (gain) loss $ — $ — $ 812 $ 391 $ — $ — Total AOCI $ — $ — $ 812 $ 391 $ — $ — Assumptions Defined Benefit Pension Plan Supplemental Non-qualified Defined Benefit Plans Non-pension Defined Benefit Postretirement Healthcare Plan 2019 2018 2017 2019 2018 2017 2019 2018 2017 Weighted-average assumptions used to determine benefit obligations: Discount rate 3.27 % 4.40 % 3.71 % 3.10 % 4.30 % 3.62 % 3.15 % 4.28 % 3.60 % Rate of increase in compensation levels 3.49 % 3.52 % 3.43 % N/A N/A N/A N/A N/A N/A Weighted-average assumptions used to determine net periodic benefit cost for plan year: Discount rate (a) 4.40 % 3.71 % 4.27 % 4.30 % 3.62 % 4.12 % 4.28 % 3.60 % 3.84 % Expected long-term rate of return on assets (b) 6.00 % 6.25 % 6.75 % N/A N/A N/A 3.00 % 3.93 % N/A Rate of increase in compensation levels 3.52 % 3.43 % 3.47 % N/A N/A N/A N/A N/A N/A _____________________________ (a) The estimated discount rate for the Defined Benefit Pension Plan is 3.27% for the calculation of the 2020 net periodic pension costs. (b) The expected rate of return on plan assets is 5.25% for the calculation of the 2020 net periodic pension cost. The healthcare benefit obligation was determined at December 31 as follows: 2019 2018 Trend Rate - Medical Pre-65 for next year 6.40 % 6.70 % Pre-65 Ultimate trend rate 4.50 % 4.50 % Trend Year 2027 2027 Post-65 for next year 4.92 % 4.94 % Post-65 Ultimate trend rate 4.50 % 4.50 % Trend Year 2028 2026 The following benefit payments to employees, which reflect future service, are expected to be paid (in thousands): Defined Benefit Pension Plan Supplemental Non-qualified Defined Benefit Plans Non-Pension Defined Benefit Postretirement Healthcare Plan 2020 $ 3,620 $ 321 $ 586 2021 $ 3,766 $ 317 $ 622 2022 $ 3,833 $ 315 $ 591 2023 $ 3,951 $ 311 $ 522 2024 $ 4,022 $ 308 $ 474 2025-2028 $ 19,882 $ 1,142 $ 1,853 |
Commitment and Contingencies
Commitment and Contingencies | 12 Months Ended |
Dec. 31, 2019 | |
Commitments and Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | COMMITMENTS AND CONTINGENCIES Power Purchase and Transmission Services Agreements We have the following power purchase and transmission services agreements, not including related party agreements, as of December 31, 2019 (see Note 14 for information on related party agreements): • A PPA with PacifiCorp, expiring December 31, 2023 , for the purchase of 50 MW of electric capacity and energy from PacifiCorp’s system. The price paid for the capacity and energy is based on the operating costs of one of PacifiCorp’s coal-fired electric generating plants. • A firm point-to-point transmission service agreement with PacifiCorp that expires December 31, 2023 . The agreement provides 50 MW of capacity and energy to be transmitted annually by PacifiCorp. • A PPA with PRPA to purchase up to 12 MW of wind energy through PRPA’s agreement with Silver Sage. This agreement will expire September 30, 2029 . Costs incurred under these agreements were as follows for the years ended December 31 (in thousands): Contract Contract Type 2019 2018 2017 PacifiCorp Electric capacity and energy $ 7,477 $ 13,681 $ 13,218 PacifiCorp Transmission access $ 1,741 $ 1,742 $ 1,671 Thunder Creek Gas transport capacity $ 422 $ 633 $ 633 PRPA Wind energy $ 688 $ 223 $ — Future Contractual Obligations The following is a schedule of future minimum payments required under power purchase, transmission services and gas supply agreements (in thousands): 2020 $ 6,531 2021 $ 6,203 2022 $ 6,203 2023 $ 6,203 2024 $ — Thereafter $ — Power Sales Agreements We have the following significant long-term power sales contracts with non-affiliated third-parties: • During periods of reduced production at Wygen III in which MDU owns a portion of the capacity, or during periods when Wygen III is off-line, MDU will be provided with 25 MW from our other generation facilities or from system purchases with reimbursement of costs by MDU. This agreement expires January 31, 2023 . • An agreement to serve MDU capacity and energy up to a maximum of 50 MW in excess of Wygen III ownership. This agreement expires December 31, 2023 . Additionally, we have firm network transmission access to deliver power on PacifiCorp’s system to Sheridan, Wyoming to serve our power sales contract with MDU through December 31, 2023 , with the right to renew pursuant to the terms of PacifiCorp’s transmission tariff. • During periods of reduced production at Wygen III in which the City of Gillette owns a portion of the capacity, or during periods when Wygen III is off-line, we will provide the City of Gillette with its first 23 MW from our other generating facilities or from system purchases with reimbursement of costs by the City of Gillette. Under this agreement, which is renewed annually on September 3, South Dakota Electric will also provide the City of Gillette their operating component of spinning reserves. • We have an amended agreement, effective January 1, 2019, to supply up to 20 MW of energy and capacity to MEAN under a contract that expires May 31, 2028 . The terms of the contract run from June 1 through May 31 for each interval listed below. This contract is unit-contingent based on the availability of our Neil Simpson II and Wygen III plants, with decreasing capacity purchased over the term of the agreement. The unit-contingent capacity amounts from Wygen III and Neil Simpson II are as follows: Contract Years Total Contract Capacity Contingent Capacity Amounts on Wygen III Contingent Capacity Amounts on Neil Simpson II 2019-2020 15 MW 10 MW 5 MW 2020-2022 15 MW 7 MW 8 MW 2022-2023 15 MW 8 MW 7 MW 2023-2028 10 MW 5 MW 5 MW • An agreement through December 31, 2021 to provide 50 MW of energy to Macquarie Energy, LLC during heavy and light load timing intervals. Environmental Matters We are subject to costs resulting from a number of federal, state and local laws and regulations which affect future planning and existing operations. They can result in increased capital expenditures, operating and other costs as a result of compliance, remediation and monitoring obligations. Due to the environmental issues discussed below, we may be required to modify, curtail, replace or cease operating certain facilities or operations to comply with statutes, regulations and other requirements of regulatory bodies. Legal Proceedings In the normal course of business, we are subject to various lawsuits, actions, proceedings, claims and other matters asserted under laws and regulations. We believe the amounts provided in the financial statements to satisfy alleged liabilities are adequate in light of the probable and estimable contingencies. However, there can be no assurance that the actual amounts required to satisfy alleged liabilities from various legal proceedings, claims and other matters discussed, and to comply with applicable laws and regulations will not exceed the amounts reflected in the financial statements. In the normal course of business, we enter into agreements that include indemnification in favor of third parties, such as information technology agreements, purchase and sale agreements and lease contracts. We have also agreed to indemnify our directors, officers and employees in accordance with our articles of incorporation, as amended. Certain agreements do not contain any limits on our liability and therefore, it is not possible to estimate our potential liability under these indemnifications. In certain cases, we have recourse against third parties with respect to these indemnities. Further, we maintain insurance policies that may provide coverage against certain claims under these indemnities. |
Related-Party Transactions
Related-Party Transactions | 12 Months Ended |
Dec. 31, 2019 | |
Related Party Transactions [Abstract] | |
Related-Party Transactions | RELATED-PARTY TRANSACTIONS Dividend to Parent We did not record any dividends in 2019 . We recorded dividends to our Parent of $36 million and changed the Utility Money Pool note by $36 million in 2018 . Receivables and Payables We have accounts receivable and accounts payable balances related to transactions with other BHC subsidiaries. These balances as of December 31 were as follows (in thousands): 2019 2018 Accounts receivable from affiliates $ 7,838 $ 8,119 Accounts payable to affiliates $ 32,121 $ 25,804 Money Pool Notes Receivable and Notes Payable We participate in the Utility Money Pool Agreement (the Agreement). Under the Agreement, we may borrow from the pool; however, the Agreement restricts the pool from loaning funds to BHC or to any of BHC’s non-utility subsidiaries. The Agreement does not restrict us from paying dividends to BHC. Borrowings under the Agreement bear interest at the weighted average daily cost of BHC’s external borrowings as defined under the Agreement, or if there are no external funds outstanding on that date, then the rate will be the daily one-month LIBOR plus 1.0% . The cost of borrowing under the Utility Money Pool was 2.21% at December 31, 2019 . We had the following balances with the Utility Money Pool as of December 31 (in thousands): 2019 2018 Money pool notes payable $ 57,585 $ 38,690 Interest income (expense) relating to the Utility Money Pool for the years ended December 31, was as follows (in thousands): 2019 2018 2017 Interest income (expense) $ (775 ) $ (401 ) $ 272 Notes payable to Parent 2019 2018 Notes payable to Parent (a) $ 25,000 $ — _______________ (a) Note bears interest at 4.51% , expired December 31, 2019, is eligible for annual renewal and was renewed through December 31, 2020. Interest payable related to this note was $0.2 million as of December 31, 2019. Interest expense allocation from Parent BHC provides daily liquidity and cash management on behalf of all its subsidiaries. For the years ended December 31, 2019 , 2018 and 2017 , we were allocated $1.2 million , $1.3 million , and $1.4 million , respectively, of interest expense from BHC. Other Balances and Transactions We have the following Power Purchase, Transmission Services, and Ground Lease Agreements with affiliated entities: • Wyoming Electric has a PPA with Happy Jack, expiring September 3, 2028 , which provides up to 30 MW of wind energy. Under a separate intercompany agreement, Wyoming Electric sells 50% of the facility output to South Dakota Electric. • Wyoming Electric has a PPA with Silver Sage, expiring September 30, 2029 , which provides up to 30 MW of wind energy. Under a separate intercompany agreement, Wyoming Electric sells 20 MW of energy from Silver Sage to South Dakota Electric. • A Generation Dispatch Agreement with Wyoming Electric that requires us to purchase all of Wyoming Electric’s excess energy. • A Wygen III Ground Lease with WDRC expiring in 2050 with three automatic renewal terms of 20 years each. Related-party Gas Transportation Service Agreement On October 1, 2014, we entered into a gas transportation service agreement with Wyoming Electric in connection with gas supply for Cheyenne Prairie. The agreement is for a term of 40 years , in which we pay a monthly service and facility fee for firm and interruptible gas transportation. Related-party Revenue and Purchases We had the following related-party transactions for the years ended December 31 included in the corresponding captions in the accompanying Statements of Income: 2019 2018 2017 (in thousands) Revenues: Energy sold to Wyoming Electric $ 1,333 $ 2,064 $ 2,481 Rent from electric properties $ 3,583 $ 3,634 $ 3,680 Horizon Point shared facility revenue $ 12,026 $ 11,211 $ 1,420 Fuel and purchased power: Purchases from WRDC mine $ 17,041 $ 17,532 $ 15,948 Purchase of excess energy from Wyoming Electric $ 856 $ 511 $ 601 Purchase of renewable wind energy from Wyoming Electric - Happy Jack $ 1,968 $ 1,942 $ 1,924 Purchase of renewable wind energy from Wyoming Electric - Silver Sage $ 3,579 $ 3,586 $ 3,290 Gas transportation service agreement with Wyoming Electric for firm and interruptible gas transportation $ 309 $ 364 $ 393 Related-party Corporate Support We had the following corporate support for the years ended December 31: 2019 2018 2017 (in thousands) Corporate support services and fees from Parent, Black Hills Service Company and Black Hills Utility Holdings $ 39,667 $ 34,578 $ 27,869 Horizon Point Shared Facilities Agreement South Dakota Electric and BHSC are parties to a shared facilities agreement, whereby BHSC is charged for the use of the Horizon Point facility that is owned by South Dakota Electric and BHSC provides certain operations and maintenance services at the facility. |
Quarterly Historical Data (Unau
Quarterly Historical Data (Unaudited) | 12 Months Ended |
Dec. 31, 2019 | |
Selected Quarterly Financial Information [Abstract] | |
Quarterly Historical Data (Unaudited) | QUARTERLY HISTORICAL DATA (Unaudited) We operate on a calendar year basis. The following table sets forth selected unaudited historical operating results data for each quarter (in thousands): First Quarter Second Quarter Third Quarter Fourth Quarter 2019 Revenues $ 79,041 $ 69,246 $ 77,022 $ 65,910 Operating income $ 24,642 $ 17,310 $ 22,004 $ 19,981 Net income $ 15,497 $ 10,148 $ 13,743 $ 7,514 2018 Revenues $ 73,815 $ 70,676 $ 78,067 $ 75,522 Operating income $ 20,364 $ 19,495 $ 21,428 $ 17,048 Net income $ 11,760 $ 11,125 $ 13,317 $ 9,443 |
Business Description and Summ_2
Business Description and Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2019 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Basis of Presentation | Basis of Presentation The financial statements include the accounts of South Dakota Electric and also our ownership interests in the assets, liabilities and expenses of our jointly owned facilities ( Note 4 ) and are prepared in accordance with GAAP. |
Use of Estimates | Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of certain assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Changes in facts and circumstances or additional information may result in revised estimates and actual results could differ materially from those estimates. |
Cash and Cash Equivalents | Cash and Cash Equivalents We consider all highly liquid investments with an original maturity of three months or less to be cash and cash equivalents. As of December 31, 2019 and 2018 , we have no cash equivalents. |
Accounts Receivable and Allowance for Doubtful Accounts | Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable consists of sales to residential, commercial, industrial, municipal and other customers all of which do not bear interest. These accounts receivable are stated at billed and unbilled amounts, net of write-offs or payment received. We maintain an allowance for doubtful accounts which reflects our best estimate of uncollectible trade receivables. We regularly review our trade receivable allowances by considering such factors as historical experience, credit worthiness, the age of the receivable balances and current economic conditions that may affect collectibility. In specific cases where we are aware of a customer’s inability or reluctance to pay, we record an allowance for doubtful accounts to reduce the net receivable balance to the amount we reasonably expect to collect. However, if circumstances change, our estimate of the recoverability of accounts receivable could be affected. Circumstances which could affect our estimates include, but are not limited to, customer credit issues, the level of commodity prices, customer deposits and general economic conditions. Accounts are written off once they are deemed to be uncollectible or the time allowed for dispute under the contract has expired. |
Materials, Supplies, and Fuel | Materials, Supplies and Fuel Materials, supplies and fuel used for construction, operation and maintenance purposes are recorded using the weighted-average cost method. |
Deferred Financing Costs | Deferred Financing Costs Deferred financing costs include loan origination fees, underwriter fees, legal fees and other costs directly attributable to the issuance of debt. Deferred financing costs are amortized over the estimated useful life of the related debt. These costs are presented on the balance sheet as an adjustment to the related debt liabilities. |
Regulatory Accounting | Regulatory Accounting Our regulated electric operations are subject to cost-of-service regulation and earnings oversight from federal and state utility commissions. We account for income and expense items in accordance with accounting standards for regulated operations: • Certain costs, which would otherwise be charged to expense or OCI, are deferred as regulatory assets based on the expected ability to recover the costs in future rates. • Certain credits, which would otherwise be reflected as income or OCI, are deferred as regulatory liabilities based on the expectation the amounts will be returned to customers in future rates, or because the amounts were collected in rates prior to the costs being incurred Management continually assesses the probability of future recoveries and obligations associated with regulatory assets and liabilities. Factors such as the current regulatory environment, recently issued rate orders, and historical precedents are considered. As a result, we believe that the accounting prescribed under rate-based regulation remains appropriate and our regulatory assets are probable of recovery in current rates or in future rate proceedings. If changes in the regulatory environment occur, we may no longer be eligible to apply this accounting treatment, and may be required to eliminate regulatory assets and liabilities from our balance sheet. Such changes could adversely affect our results of operations, financial position or cash flows. As of December 31, 2019 and 2018, we had total regulatory assets of $76 million and $76 million respectively, and total regulatory liabilities of $166 million and $163 million respectively. See Note 7 for further information. |
Property, Plant and Equipment | Property, Plant and Equipment Additions to property, plant and equipment are recorded at cost. Included in the cost of regulated construction projects is AFUDC, when applicable, which represents the approximate composite cost of borrowed funds and a return on equity used to finance a regulated utility project. The cost of regulated utility property, plant and equipment retired, or otherwise disposed of in the ordinary course of business, less salvage plus retirement costs, is charged to accumulated depreciation. Estimated removal costs associated with non-legal retirement obligations related to our regulated electric properties are reclassified from accumulated depreciation and reflected as regulatory liabilities. Ordinary repairs and maintenance of property, except as allowed under rate regulations, are charged to operations as incurred. Property, plant and equipment is tested for impairment when it is determined that the carrying value of the assets may not be recoverable. A loss is recognized in the current period if it becomes probable that part of a cost of a plant under construction or recently completed plant will be disallowed for recovery from customers and a reasonable estimate of the disallowance can be made. For investments in property, plant and equipment that are abandoned and not expected to go into service, incurred costs and related deferred tax amounts are compared to the discounted estimated future rate recovery, and a loss is recognized, if necessary. Depreciation provisions for regulated electric property, plant and equipment are computed on a straight-line basis using an annual composite rate of 2.2% in 2019 , 2.3% in 2018 and 2.1% in 2017 . |
Derivatives and Hedging Activities | Derivatives and Hedging Activities Derivatives are measured at fair value and recognized as either assets or liabilities on the Balance Sheets, except for derivative contracts that qualify for and are elected under the normal purchase and normal sales exception. Normal purchases and normal sales are contracts where physical delivery is probable, quantities are expected to be used or sold in the normal course of business over a reasonable amount of time, and price is not tied to an unrelated underlying derivative. Normal purchase and sales contracts are recognized when the underlying physical transaction is completed under the accrual basis of accounting. As part of our operations, we enter into contracts to buy and sell energy to meet the requirements of our customers. From time to time we utilize risk management contracts including interest rate swaps to fix the interest on variable rate debt, or to lock in the Treasury yield component associated with anticipated issuance of senior notes. For swaps that settled in connection with the issuance of senior debt, the effective portion is deferred as a component in AOCI and recognized as interest expense over the life of the senior note. As of December 31, 2019 , we have no outstanding interest rate swap agreements. We utilize master netting agreements which consist of an agreement between two parties who have multiple contracts with each other that provide for the net settlement of all contracts in the event of default on or termination of any one contract. When the right of offset exists, accounting standards permit the netting of receivables and payables under a legally enforceable master netting agreement between counterparties. Accounting standards also permit offsetting of fair value amounts recognized for the right to reclaim, or the obligation to return, cash collateral against fair value amounts recognized for derivative instruments executed with the same counterparty. We reflect the offsetting of net derivative positions with fair value amounts for cash collateral with the same counterpart when a legal right of offset exists. |
Fair Value Measurements | Fair Value Measurements Financial Instruments We use the following fair value hierarchy for determining inputs for our financial instruments. Our assets and liabilities for financial instruments are classified and disclosed in one of the following fair value categories: Level 1 — Unadjusted quoted prices available in active markets that are accessible at the measurement date for identical unrestricted assets or liabilities. Level 1 instruments primarily consist of highly liquid and actively traded financial instruments with quoted pricing information on an ongoing basis. Level 2 — Pricing inputs include quoted prices for identical or similar assets and liabilities in active markets other than quoted prices in Level 1, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability and inputs that are derived principally from or corroborated by observable market data by correlation or other means. Level 3 — Pricing inputs are generally less observable from objective sources. These inputs reflect management’s best estimate of fair value using its own assumptions about the assumptions a market participant would use in pricing the asset or liability. Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the placement within the fair value hierarchy levels. We record transfers, if necessary, between levels at the end of the reporting period for all of our financial instruments. Transfers into Level 3, if any, occur when significant inputs used to value the derivative instruments become less observable, such as a significant decrease in the frequency and volume in which the instrument is traded, negatively impacting the availability of observable pricing inputs. Transfers out of Level 3, if any, occur when the significant inputs become more observable, such as when the time between the valuation date and the delivery date of a transaction becomes shorter, positively impacting the availability of observable pricing inputs. We currently do not have any Level 3 investments. |
Income Taxes | Income Taxes We file a federal income tax return with other members of the Parent’s consolidated group. For financial statement purposes, federal income taxes are allocated to the individual companies based on amounts calculated on a separate return basis. The Company uses the asset and liability method in accounting for income taxes. Under the asset and liability method, deferred income taxes are recognized at currently enacted income tax rates, to reflect the tax effect of temporary differences between the financial and tax basis of assets and liabilities as well as operating loss and tax credit carryforwards. Such temporary differences are the result of provisions in the income tax law that either require or permit certain items to be reported on the income tax return in a different period than they are reported in the financial statements. We use the deferral method of accounting for investment tax credits as allowed by our rate-regulated jurisdictions. Such a method results in the investment tax credit being amortized as a reduction to income tax expense over the estimated useful lives of the underlying property that gave rise to the credit. We recognize interest income or interest expense and penalties related to income tax matters in Income tax expense on the Statements of Income . |
Recently Issued and Adopted Accounting Standards | Recently Issued Accounting Standards Simplifying the Accounting for Income Taxes, ASU 2019-12 In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes as part of its overall simplification initiative to reduce costs and complexity in applying accounting standards while maintaining or improving the usefulness of the information provided to users of the financial statements. Amendments include removal of certain exceptions to the general principles of ASC 740, Income Taxes , and simplification in several other areas such as accounting for a franchise tax (or similar tax) that is partially based on income. The new guidance is effective for interim and annual periods beginning after December 15, 2020 with early adoption permitted. We are currently reviewing this standard to assess the impact on our financial position, results of operations and cash flows. Internal-Use Software: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, ASU 2018-15 In August 2018, the FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, which aligns the requirements for recording implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. As a result, certain categories of implementation costs that previously would have been charged to expense as incurred are now capitalized as prepayments and amortized over the term of the arrangement. The new guidance is effective for annual periods beginning after December 15, 2019, and interim periods within those fiscal years. The new guidance can be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. Early adoption is permitted. We adopted this standard prospectively on January 1, 2020. Adoption of this guidance did not have a material impact on our financial position, results of operations or cash flows. Financial Instruments -- Credit Losses: Measurement of Credit Losses on Financial Instruments, ASU 2018-19 In June 2016, the FASB issued ASU 2016-13, Financial Instruments -- Credit Losses: Measurement of Credit Losses on Financial Instruments, which was subsequently amended by ASU 2018-19, ASU 2019-04, 2019-05, 2019-10, and 2019-11. The standard introduces new accounting guidance for credit losses on financial instruments within its scope, including trade receivables. This new guidance adds an impairment model that is based on expected losses rather than incurred losses. It is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted. We adopted this standard on January 1, 2020 with prior year comparative financial information remaining as previously reported when transitioning to the new standard. On January 1, 2020, we recorded an increase to our allowance for doubtful accounts, primarily associated with the inclusion of expected losses on unbilled revenue. Adoption of this standard did not have a material impact on our financial position, results of operations or cash flows. Recently Adopted Accounting Standards Leases, ASU 2016-02 In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) , to increase transparency and comparability among organizations by requiring the recognition of right-of-use assets and lease liabilities on the balance sheet for most leases, whereas previously only financing-type lease liabilities (capital leases) were recognized on the balance sheet. Under the new standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing and uncertainty of cash flows arising from leases. We adopted the standard effective January 1, 2019. We elected not to recast comparative periods coinciding with the new lease standard transition and will report these comparative periods as presented under previous lease guidance. In addition, we elected the package of practical expedients permitted under the transition guidance with the new standard, which among other things, allowed us to carry forward the historical lease classification. We also elected the practical expedient related to land easements, allowing us to carry forward our accounting treatment for existing land easements agreements. Adoption of the new standard resulted in the recording of an operating lease right-of-use asset and off-setting obligation liability of $14 million , primarily for the Wygen III ground lease, as of January 1, 2019. See Note 8 |
Revenue | Our revenue contracts generally provide for performance obligations that are fulfilled and transfer control to customers over time, represent a series of distinct services that are substantially the same, involve the same pattern of transfer to the customer, and provide a right to consideration from our customers in an amount that corresponds directly with the value to the customer for the performance completed to date. Therefore, we recognize revenue in the amount to which we have a right to invoice. Our primary types of revenue contracts are: • Regulated electric utility services tariffs - Our regulated operations, as defined by ASC 980, provide services to regulated customers under tariff rates, charges, terms and conditions of service, and prices determined by the jurisdictional regulators designated for our service territories. Our regulated services primarily encompass single performance obligations for delivery of commodity electricity and electric transmission services. These service revenues are variable based on quantities delivered, influenced by seasonal business and weather patterns. Tariffs are only permitted to be changed through a rate-setting process involving the state or federal regulatory commissions to establish contractual rates between the utility and its customers. All of our regulated utility sales are subject to regulatory-approved tariffs. • Power sales agreements - We have long-term wholesale power sales agreements with other load serving entities for the sale of excess power from owned generating units. In addition to these long-term contracts, the Company also sells excess energy to other load-serving entities on a short-term basis. The pricing for all of these arrangements is included in the executed contracts or confirmations, reflecting the standalone selling price, and is variable based on energy delivered. The following table depicts the disaggregation of revenue, including intercompany revenue, from contracts with customers by customer type and timing of revenue recognition. Sales tax and other similar taxes are excluded from revenues. Year ended December 31, 2019 Year ended December 31, 2018 (in thousands) Customer types: Retail $ 202,569 $ 197,184 Wholesale 19,078 33,687 Market - off-system sales 16,475 17,691 Transmission/Other 50,329 49,015 Revenue from contracts with customers 288,451 297,577 Other revenues 2,768 503 Total revenues $ 291,219 $ 298,080 Timing of revenue recognition: Services transferred over time $ 288,451 $ 297,577 Revenue from contracts with customers $ 288,451 $ 297,577 The majority of our revenue contracts are based on variable quantities delivered; any fixed consideration contracts with an expected duration of one year or more are immaterial to our revenues. Variable consideration constraints in the form of discounts, rebates, credits, price concessions, incentives, performance bonuses, penalties or other similar items are not material for our revenue contracts. We are the principal in our revenue contracts, as we have control over the services prior to those services being transferred to the customer. Revenue Not in Scope of ASC 606 Other revenues included in the table above include revenue accounted for under separate accounting guidance, including alternative revenue programs revenue under ASC 980. Significant Judgments and Estimates Unbilled Revenue To the extent that deliveries have occurred but a bill has not been issued, the Company accrues an estimate of the revenue since the latest billing. This estimate is calculated based on several factors including billings through the last billing cycle in a month and prices in effect in our jurisdictions. Each month the estimated unbilled revenue amounts are trued-up and recorded in Accounts receivable, net on the accompanying Balance Sheets. Contract Balances The nature of our primary revenue contracts provides an unconditional right to consideration upon service delivery; therefore, no customer contract assets or liabilities exist. The unconditional right to consideration is represented by the balance in our Accounts Receivable and is further discussed above. We do not typically incur costs that would be capitalized, to obtain or fulfill a contract. |
Business Description and Summ_3
Business Description and Summary of Significant Accounting Policies (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Schedule of Accounts, Notes, Loans and Financing Receivable | Following is a summary of accounts receivable as of December 31 (in thousands): 2019 2018 Accounts receivable, trade $ 14,778 $ 16,236 Unbilled revenue 10,914 12,333 Less Allowance for doubtful accounts (160 ) (138 ) Accounts receivable, net $ 25,532 $ 28,431 |
SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] | Changes to allowance for doubtful accounts for the years ended December 31, were as follows (in thousands): Balance at beginning of year Additions charged to costs and expenses Deductions charged to costs and expenses Balance at end of year 2019 $ 138 $ 899 $ (877 ) $ 160 2018 $ 224 $ 911 $ (997 ) $ 138 2017 $ 157 $ 882 $ (815 ) $ 224 |
Schedule of Accrued Liabilities | The following amounts by major classification are included in Accrued liabilities on the accompanying Balance Sheets as of December 31 (in thousands): 2019 2018 Accrued employee compensation, benefits and withholdings $ 4,387 $ 4,206 Accrued property taxes 6,685 6,332 Accrued income taxes 1,946 12,536 Customer deposits and prepayments 5,486 5,204 Accrued interest 4,935 4,627 Other (none of which is individually significant) 2,053 1,288 Total accrued liabilities $ 25,492 $ 34,193 |
Revenue (Tables)
Revenue (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Revenue from Contract with Customer [Abstract] | |
Disaggregation of Revenue | The following table depicts the disaggregation of revenue, including intercompany revenue, from contracts with customers by customer type and timing of revenue recognition. Sales tax and other similar taxes are excluded from revenues. Year ended December 31, 2019 Year ended December 31, 2018 (in thousands) Customer types: Retail $ 202,569 $ 197,184 Wholesale 19,078 33,687 Market - off-system sales 16,475 17,691 Transmission/Other 50,329 49,015 Revenue from contracts with customers 288,451 297,577 Other revenues 2,768 503 Total revenues $ 291,219 $ 298,080 Timing of revenue recognition: Services transferred over time $ 288,451 $ 297,577 Revenue from contracts with customers $ 288,451 $ 297,577 |
Property, Plant and Equipment (
Property, Plant and Equipment (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Property, Plant and Equipment [Abstract] | |
Property, Plant and Equipment | Property, plant and equipment at December 31 consisted of the following (dollars in thousands): 2019 2018 Weighted Weighted Average Average 2019 Useful Life (in years) 2018 Useful Life (in years) Property, plant, and equipment: Production $ 612,517 46 $ 588,565 46 Transmission 235,390 51 208,610 48 Distribution 431,783 46 394,475 45 Plant acquisition adjustment (a) 4,870 32 4,870 32 General 165,342 29 154,621 28 Total plant-in-service 1,449,902 1,351,141 Construction work in progress 44,768 29,904 Total property, plant and equipment 1,494,670 1,381,045 Less accumulated depreciation and amortization (400,054 ) (376,160 ) Total property, plant and equipment, net $ 1,094,616 $ 1,004,885 __________________ (a) The plant acquisition adjustment is included in rate base and is being recovered with 11 years remaining. |
Jointly Owned Facilities (Table
Jointly Owned Facilities (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Jointly Owned Utility Plant, Net Ownership Amount [Abstract] | |
Schedule Of Jointly Owned Facilities | As of December 31, 2019 , our interests in jointly-owned generating facilities and transmission systems were (in thousands): Interest in jointly-owned facilities Plant in Service Construction Work in Progress Less Accumulated Depreciation Plant Net of Accumulated Depreciation Wyodak Plant $ 116,074 $ 729 $ (64,413 ) $ 52,390 Transmission Tie $ 19,862 $ 4,161 $ (6,612 ) $ 17,411 Wygen III $ 146,161 $ 400 $ (25,518 ) $ 121,043 Cheyenne Prairie $ 92,684 $ 532 $ (14,202 ) $ 79,014 |
Long-term Debt (Tables)
Long-term Debt (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Long-term Debt, Unclassified [Abstract] | |
Schedule of Long-term Debt Instruments | Long-term debt outstanding at December 31 was as follows (in thousands): Interest Rate at Balance Outstanding Due Date December 31, 2019 December 31, 2019 December 31, 2018 First Mortgage Bonds due 2032 August 15, 2032 7.23 % 75,000 75,000 First Mortgage Bonds due 2039 November 1, 2039 6.13 % 180,000 180,000 First Mortgage Bonds due 2044 October 20, 2044 4.43 % 85,000 85,000 Series 94A Debt (a) June 1, 2024 1.84 % 2,855 2,855 Less unamortized debt discount (82 ) (86 ) Less unamortized deferred financing costs (2,597 ) (2,734 ) Long-term Debt, net 340,176 340,035 ___________________ (a) Variable interest rate at December 31, 2019 . |
Schedule of Maturities of Long-term Debt | Scheduled maturities of our outstanding long-term debt (excluding unamortized discounts and unamortized deferred financing costs) are as follows (in thousands): 2020 $ — 2021 $ — 2022 $ — 2023 $ — 2024 $ 2,855 Thereafter $ 340,000 |
Fair Value of Financial Instr_2
Fair Value of Financial Instruments (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Fair Value Disclosures [Abstract] | |
Fair Value of Financial Instruments | The estimated fair values of our financial instruments at December 31 were as follows (in thousands): 2019 2018 Carrying Value Fair Value Carrying Value Fair Value Cash (a) $ 6 $ 6 $ 112 $ 112 Notes payable to Parent (b) $ 25,000 $ 25,000 $ — $ — Long-term debt (c) $ 340,176 $ 458,286 $ 340,035 $ 412,894 _______________ (a) The cash fair value approximates carrying value and therefore is classified as Level 1 in the fair value hierarchy. We believe that the market risk arising from cash in a bank account is minimal. (b) Carrying value approximates fair value due to the short-term length of maturity; since these borrowings are not traded on an exchange, they are classified in Level 2 in the fair value hierarchy. (c) Long-term debt is valued based on observable inputs available either directly or indirectly for similar liabilities in active markets and therefore is classified as Level 2 in the fair value hierarchy. Carrying amount of long-term debt is net of deferred financing costs. |
Regulatory Matters (Tables)
Regulatory Matters (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Regulated Operations [Abstract] | |
Schedule of Regulatory Assets and Liabilities | We had the following regulatory assets and liabilities as of December 31 (in thousands): 2019 2018 Regulatory assets Loss on reacquired debt (a) $ 989 $ 1,259 Deferred taxes on AFUDC (b) 4,927 5,020 Employee benefit plans and related deferred taxes (c) 20,661 19,868 Deferred energy and fuel cost adjustments (a) 23,203 20,334 Deferred taxes on flow through accounting (c) 9,801 8,749 Decommissioning costs (b) 6,211 8,196 Vegetation management (a) 8,062 10,366 Other regulatory assets (a) 1,843 1,940 Total regulatory assets 75,697 75,732 Less current regulatory assets (21,588 ) (19,052 ) Regulatory assets, non-current $ 54,109 $ 56,680 Regulatory liabilities Cost of removal for utility plant (a) $ 57,318 $ 52,366 Employee benefit plans and related deferred taxes (c) 7,023 7,518 Excess deferred income taxes (c) 98,228 100,276 TCJA revenue reserve 3,162 2,523 Other regulatory liabilities (c) 440 533 Total regulatory liabilities 166,171 163,216 Less current regulatory liabilities (3,162 ) (2,574 ) Regulatory liabilities, non-current $ 163,009 $ 160,642 ____________________ (a) We are allowed a recovery of costs but we are not allowed a rate of return. (b) In addition to recovery of costs, we are allowed a rate of return. (c) In addition to recovery or repayment of costs, we are allowed a return on a portion of this amount or a reduction in rate base. |
Leases (Tables)
Leases (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Leases [Abstract] | |
Lease, Cost | The components of lease expense were as follows (in thousands): Income Statement Location For the year ended December 31, 2019 Operating lease cost Operations and maintenance $ 908 Variable lease cost Operations and maintenance 137 Total lease cost $ 1,045 |
Lessee Supplemental Balance Sheet Information Related to Leases | Supplemental balance sheet information related to leases was as follows (in thousands): Balance Sheet Location As of December 31, 2019 Assets: Operating lease assets Other assets, non-current $ 14,374 Total lease assets $ 14,374 Liabilities: Current: Operating leases Accrued liabilities $ 293 Noncurrent: Operating leases Other deferred credits and other liabilities 14,105 Total lease liabilities $ 14,398 |
Lessee Supplemental Cash Flow Information Related to Leases | Supplemental cash flow information related to leases was as follows (in thousands): For the year ended December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 912 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ — |
Lessee Supplemental Weighted Average Schedule Related to Leases | As of December 31, 2019 Weighted average remaining lease term (years): Operating leases 30 years Weighted average discount rate: Operating leases 4.3 % |
Lessee, Operating Lease, Liability, Maturity | Scheduled maturities of operating lease liabilities for future years were as follows (in thousands): Total 2020 $ 912 2021 911 2022 911 2023 908 2024 906 Thereafter 21,128 Total lease payments 25,676 Less imputed interest 11,278 Present value of lease liabilities $ 14,398 As previously disclosed in Note 11 of the Notes to the Financial Statements in our 2018 Annual Report on Form 10-K, prior to the adoption of ASU 2016-02, Leases (Topic 842), the future minimum payments required under operating lease agreements as of December 31, 2018 were as follows (in thousands): Operating Leases 2019 $ 911 2020 856 2021 855 2022 856 2023 853 Thereafter 21,947 Total lease payments $ 26,278 |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Income Tax Disclosure [Abstract] | |
Schedule of Components of Income Tax Expense (Benefit) | Income tax expense for the years ended December 31 was as follows (in thousands): 2019 2018 2017 Current: Federal $ 13,782 $ 5,454 $ 13,124 Deferred: Federal (4,281 ) 5,218 1,004 Total income tax expense $ 9,501 $ 10,672 $ 14,128 |
Schedule of Deferred Tax Assets and Liabilities | The temporary differences, which gave rise to the net deferred tax liability, for the years ended December 31 were as follows (in thousands): 2019 2018 Deferred tax assets: Regulatory liabilities $ 25,623 $ 25,587 Other 9,128 4,721 Total deferred tax assets 34,751 30,308 Deferred tax liabilities: Accelerated depreciation and other plant related differences (125,138 ) (125,594 ) Regulatory assets (7,193 ) (7,147 ) Deferred costs (8,264 ) (8,572 ) Other (6,358 ) (3,004 ) Total deferred tax liabilities (146,953 ) (144,317 ) Net deferred tax liability $ (112,202 ) $ (114,009 ) |
Schedule of Effective Income Tax Rate Reconciliation | The effective tax rate differs from the federal statutory rate for the years ended December 31, as follows: 2019 2018 2017 Federal statutory rate 21.0% 21.0% 35.0% Amortization of excess deferred and investment tax credits (3.0) (1.3) (0.1) Flow-through adjustments (a) (1.5) (1.7) (1.8) TCJA corporate rate reduction (b) — 2.5 (9.2) Other 0.3 (1.6) (2.3) 16.8% 18.9% 21.6% _________________________ (a) Flow-through adjustments related primarily to an accounting method for tax purposes that allows us to take a current tax deduction for repair costs. We recorded a deferred income tax liability in recognition of the temporary difference created between book and tax treatment and we flowed the tax benefit through to tax expense. (b) On December 22, 2017, the TCJA was signed into law reducing the federal corporate rate from 35% to 21% , effective January 1, 2018. The 2017 effective tax rate reduction reflects the revaluation of deferred income taxes required by the change. During the year ended December 31, 2018, we recorded approximately $0.9 million of additional tax expense associated with changes in the prior estimated impacts of TCJA related items. |
Summary of Deferred Tax Liability Not Recognized | The following table reconciles the total amounts of unrecognized tax benefits, without interest, included in Other deferred credits and other liabilities on the accompanying Balance Sheet (in thousands): 2019 2018 Unrecognized tax benefits at January 1 $ 249 $ 302 Additions for current year tax positions — — Additions for prior year tax positions — 2 Reductions for prior year tax positions (33 ) (55 ) Unrecognized tax benefits at December 31 $ 216 $ 249 |
Comprehensive Income (Tables)
Comprehensive Income (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] | |
Reclassification out of Accumulated Other Comprehensive Income | The following table details reclassifications out of AOCI and into net income. The amounts in parentheses below indicate decreases to net income in the Statements of Income for the period, net of tax (in thousands): Location on the Statements of Income Amounts Reclassified from AOCI December 31, 2019 December 31, 2018 Gains and (losses) on cash flow hedges: Interest rate swaps Interest expense $ (64 ) $ (64 ) Income tax Income tax benefit (expense) 132 13 Total reclassification adjustments related to cash flow hedges, net of tax $ 68 $ (51 ) Amortization of components of defined benefit plans: Actuarial gain (loss) Operations and maintenance $ (65 ) $ (103 ) Income tax Income tax benefit (expense) 166 22 Total reclassification adjustments related to defined benefit plans, net of tax $ 101 $ (81 ) |
Schedule of Accumulated Other Comprehensive Income (Loss) | Balances by classification included within AOCI, net of tax, on the accompanying Balance Sheets were as follows (in thousands): Derivatives Designated as Cash Flow Hedges Interest Rate Swaps Employee Benefit Plans Total As of December 31, 2018 $ (500 ) $ (391 ) $ (891 ) Other comprehensive income (loss) before reclassifications — (320 ) (320 ) Amounts reclassified from AOCI (68 ) (101 ) (169 ) As of December 31, 2019 $ (568 ) $ (812 ) $ (1,380 ) Derivatives Designated as Cash Flow Hedges Interest Rate Swaps Employee Benefit Plans Total As of December 31, 2017 $ (551 ) $ (707 ) $ (1,258 ) Other comprehensive income (loss) before reclassifications — 235 235 Amounts reclassified from AOCI 51 81 132 As of December 31, 2018 $ (500 ) $ (391 ) $ (891 ) |
Supplemental Cash Flow Inform_2
Supplemental Cash Flow Information (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Supplemental Cash Flow Information [Abstract] | |
Schedule of Cash Flow, Supplemental Disclosures | Years ended December 31, 2019 2018 2017 (in thousands) Non-cash investing and financing activities - Accrued property, plant and equipment purchases at December 31 $ 12,305 $ 15,180 $ 6,565 Non-cash decrease to money pool note receivable, net $ — $ (36,000 ) $ (42,000 ) Non-cash dividend to Parent $ — $ 36,000 $ 42,000 Cash (paid) refunded during the period for - Interest (net of amounts capitalized) $ (21,909 ) $ (21,988 ) $ (21,517 ) Income taxes (paid), net $ (24,372 ) $ (10,394 ) $ (12,719 ) |
Employee Benefit Plans (Tables)
Employee Benefit Plans (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Defined Benefit Plan Disclosure [Line Items] | |
Schedule of Allocation of Plan Assets | The percentages of total plan asset by investment category of our Pension Plan assets at December 31 were as follows: 2019 2018 Equity securities 20 % 17 % Real estate 3 4 Fixed income funds 71 71 Cash and cash equivalents 2 3 Hedge funds 4 5 Total 100 % 100 % |
Schedule of Contribution to Employee Plans | Contributions for the years ended December 31 were as follows (in thousands): 2019 2018 Defined Contribution Plan Company retirement contributions $ 888 $ 876 Company matching contributions $ 1,275 $ 1,272 2019 2018 Defined Benefit Plans Defined Benefit Pension Plan $ 1,753 $ 1,795 Non-Pension Defined Benefit Postretirement Healthcare Plan $ 739 $ 388 Supplemental Non-qualified Defined Benefit Plans $ 266 $ 238 |
Schedule of Changes in Projected Benefit Obligations | Benefit Obligations Defined Benefit Pension Plan Supplemental Non-qualified Defined Benefit Plans Non-pension Defined Benefit Postretirement Healthcare Plan As of December 31 (in thousands) 2019 2018 2019 2018 2019 2018 Change in benefit obligation: Projected benefit obligation at beginning of year $ 61,919 $ 67,562 $ 2,992 $ 3,418 $ 5,055 $ 5,970 Service cost 365 516 — — 148 193 Interest cost 2,410 2,194 114 108 186 179 Actuarial loss (gain) 7,482 (2,878 ) 406 (296 ) 507 (889 ) Benefits paid (5,234 ) (3,562 ) (266 ) (238 ) (739 ) (389 ) Plan participants transfer to affiliate 119 (1,913 ) — — (77 ) (129 ) Plan participants’ contributions — — — — 96 120 Projected benefit obligation at end of year $ 67,061 $ 61,919 $ 3,246 $ 2,992 $ 5,176 $ 5,055 |
Schedule of Changes in Fair Value of Plan Assets | Employee Benefit Plan Assets Defined Benefit Pension Plan Supplemental Non-qualified Defined Benefit Plans Non-pension Defined Benefit Postretirement Healthcare Plan As of December 31 (in thousands) 2019 2018 2019 2018 2019 2018 Beginning fair value of plan assets $ 54,664 $ 59,884 $ — $ — $ — $ — Investment income (loss) 8,902 (1,884 ) — — — — Employer contributions 1,753 1,795 266 238 643 268 Retiree contributions — — — — 96 120 Benefits paid (5,234 ) (3,563 ) (266 ) (238 ) (739 ) (388 ) Plan participants transfer to affiliate 105 (1,568 ) — — — — Ending fair value of plan assets $ 60,190 $ 54,664 $ — $ — $ — $ — |
Schedule of Amounts Recognized in Balance Sheet | The funded status of the plans and amounts recognized in the Balance Sheets at December 31 consist of (in thousands): Defined Benefit Pension Plan Supplemental Non-qualified Defined Benefit Plans Non-pension Defined Benefit Postretirement Healthcare Plan 2019 2018 2019 2018 2019 2018 Regulatory asset $ 20,117 $ 19,099 $ — $ — $ — $ — Current liability $ — $ — $ 321 $ 230 $ 586 $ 466 Non-current liability $ 7,121 $ 7,255 $ 2,925 $ 2,762 $ 4,590 $ 4,589 Regulatory liability $ — $ — $ — $ — $ 1,675 $ 2,441 |
Schedule of Accumulated and Projected Benefit Obligations | Accumulated Benefit Obligation Defined Benefit Pension Plan Supplemental Non-pension Defined Benefit Postretirement Healthcare Plan As of December 31 (in thousands) 2019 2018 2019 2018 2019 2018 Accumulated benefit obligation $ 65,225 $ 59,987 $ 3,246 $ 2,992 $ 5,176 $ 5,055 |
Schedule of Net Benefit Costs | Net periodic expense consisted of the following for the year ended December 31 (in thousands): Defined Benefit Pension Plan Supplemental Non-pension Defined Benefit Postretirement Healthcare Plan 2019 2018 2017 2019 2018 2017 2019 2018 2017 Service cost $ 365 $ 516 $ 545 $ — $ — $ — $ 148 $ 193 $ 206 Interest cost 2,410 2,194 2,341 114 108 116 186 179 176 Expected return on assets (3,405 ) (3,545 ) (3,591 ) — — — — — — Amortization of prior service cost (credits) 10 43 43 — — — (336 ) (336 ) (336 ) Recognized net actuarial loss (gain) 1,221 2,063 1,230 65 103 87 — — — Net periodic expense $ 601 $ 1,271 $ 568 $ 179 $ 211 $ 203 $ (2 ) $ 36 $ 46 |
Schedule of Net Periodic Benefit Cost Not yet Recognized | For defined benefit plans, amounts included in AOCI, after-tax, that have not yet been recognized as components of net periodic benefit cost at December 31 were as follows (in thousands): Defined Benefit Pension Plan Supplemental Non-qualified Defined Benefit Plans Non-pension Defined Benefit Postretirement Healthcare Plan 2019 2018 2019 2018 2019 2018 Net (gain) loss $ — $ — $ 812 $ 391 $ — $ — Total AOCI $ — $ — $ 812 $ 391 $ — $ — |
Schedule of Assumptions Used | Assumptions Defined Benefit Pension Plan Supplemental Non-qualified Defined Benefit Plans Non-pension Defined Benefit Postretirement Healthcare Plan 2019 2018 2017 2019 2018 2017 2019 2018 2017 Weighted-average assumptions used to determine benefit obligations: Discount rate 3.27 % 4.40 % 3.71 % 3.10 % 4.30 % 3.62 % 3.15 % 4.28 % 3.60 % Rate of increase in compensation levels 3.49 % 3.52 % 3.43 % N/A N/A N/A N/A N/A N/A Weighted-average assumptions used to determine net periodic benefit cost for plan year: Discount rate (a) 4.40 % 3.71 % 4.27 % 4.30 % 3.62 % 4.12 % 4.28 % 3.60 % 3.84 % Expected long-term rate of return on assets (b) 6.00 % 6.25 % 6.75 % N/A N/A N/A 3.00 % 3.93 % N/A Rate of increase in compensation levels 3.52 % 3.43 % 3.47 % N/A N/A N/A N/A N/A N/A _____________________________ (a) The estimated discount rate for the Defined Benefit Pension Plan is 3.27% for the calculation of the 2020 net periodic pension costs. (b) The expected rate of return on plan assets is 5.25% for the calculation of the 2020 net periodic pension cost. |
Schedule of Health Care Cost Trend Rates | The healthcare benefit obligation was determined at December 31 as follows: 2019 2018 Trend Rate - Medical Pre-65 for next year 6.40 % 6.70 % Pre-65 Ultimate trend rate 4.50 % 4.50 % Trend Year 2027 2027 Post-65 for next year 4.92 % 4.94 % Post-65 Ultimate trend rate 4.50 % 4.50 % Trend Year 2028 2026 |
Schedule of Expected Benefit Payments | The following benefit payments to employees, which reflect future service, are expected to be paid (in thousands): Defined Benefit Pension Plan Supplemental Non-qualified Defined Benefit Plans Non-Pension Defined Benefit Postretirement Healthcare Plan 2020 $ 3,620 $ 321 $ 586 2021 $ 3,766 $ 317 $ 622 2022 $ 3,833 $ 315 $ 591 2023 $ 3,951 $ 311 $ 522 2024 $ 4,022 $ 308 $ 474 2025-2028 $ 19,882 $ 1,142 $ 1,853 |
Defined Benefit Pension Plan | |
Defined Benefit Plan Disclosure [Line Items] | |
Schedule of Allocation of Plan Assets | The following tables set forth, by level within the fair value hierarchy, the assets that were accounted for at fair value on a recurring basis (in thousands): Pension Plan December 31, 2019 Level 1 Level 2 Level 3 Total Investments Measured at Fair Value NAV (a) Total Investments AXA Equitable General Fixed Income $ — $ 8 $ — $ 8 $ — $ 8 Common Collective Trust - Cash and Cash Equivalents — 978 — 978 — 978 Common Collective Trust - Equity — 12,072 — 12,072 — 12,072 Common Collective Trust - Fixed Income — 42,449 — 42,449 — 42,449 Common Collective Trust - Real Estate — — — — 1,974 1,974 Hedge Funds — — — — 2,709 2,709 Total investments measured at fair value $ — $ 55,507 $ — $ 55,507 $ 4,683 $ 60,190 Pension Plan December 31, 2018 Level 1 Level 2 Level 3 Total Investments Measured at Fair Value NAV (a) Total Investments AXA Equitable General Fixed Income $ — $ 261 $ — $ 261 $ — $ 261 Common Collective Trust - Cash and Cash Equivalents — 1,388 — 1,388 — 1,388 Common Collective Trust - Equity — 9,436 — 9,436 — 9,436 Common Collective Trust - Fixed Income — 39,047 — 39,047 — 39,047 Common Collective Trust - Real Estate — 9 — 9 1,896 1,905 Hedge Funds — — — — 2,627 2,627 Total investments measured at fair value $ — $ 50,141 $ — $ 50,141 $ 4,523 $ 54,664 ________________________ (a) Certain investments that are measured at fair value using NAV per share (or its equivalent) for practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in these tables for these investments are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the reconciliation of changes in the plan’s benefit obligations and fair value of plan assets above. |
Commitment and Contingencies (T
Commitment and Contingencies (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Commitments and Contingencies Disclosure [Abstract] | |
Long-term Purchase Commitment | Costs incurred under these agreements were as follows for the years ended December 31 (in thousands): Contract Contract Type 2019 2018 2017 PacifiCorp Electric capacity and energy $ 7,477 $ 13,681 $ 13,218 PacifiCorp Transmission access $ 1,741 $ 1,742 $ 1,671 Thunder Creek Gas transport capacity $ 422 $ 633 $ 633 PRPA Wind energy $ 688 $ 223 $ — |
Unrecorded Unconditional Purchase Obligations Disclosure | The following is a schedule of future minimum payments required under power purchase, transmission services and gas supply agreements (in thousands): 2020 $ 6,531 2021 $ 6,203 2022 $ 6,203 2023 $ 6,203 2024 $ — Thereafter $ — |
Schedule of Unit Contingent Capacity | The unit-contingent capacity amounts from Wygen III and Neil Simpson II are as follows: Contract Years Total Contract Capacity Contingent Capacity Amounts on Wygen III Contingent Capacity Amounts on Neil Simpson II 2019-2020 15 MW 10 MW 5 MW 2020-2022 15 MW 7 MW 8 MW 2022-2023 15 MW 8 MW 7 MW 2023-2028 10 MW 5 MW 5 MW |
Related-Party Transactions (Tab
Related-Party Transactions (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Related Party Transactions [Abstract] | |
Schedule of Related Party Accounts Receivable and Payable | We have accounts receivable and accounts payable balances related to transactions with other BHC subsidiaries. These balances as of December 31 were as follows (in thousands): 2019 2018 Accounts receivable from affiliates $ 7,838 $ 8,119 Accounts payable to affiliates $ 32,121 $ 25,804 |
Schedule of Related Party Notes and Associated Interest Income Expense | We had the following balances with the Utility Money Pool as of December 31 (in thousands): 2019 2018 Money pool notes payable $ 57,585 $ 38,690 |
Schedule of Related Party Interest Income Expense | Interest income (expense) relating to the Utility Money Pool for the years ended December 31, was as follows (in thousands): 2019 2018 2017 Interest income (expense) $ (775 ) $ (401 ) $ 272 |
Schedule of Notes Payable to Parent Company | Notes payable to Parent 2019 2018 Notes payable to Parent (a) $ 25,000 $ — _______________ (a) Note bears interest at 4.51% , expired December 31, 2019, is eligible for annual renewal and was renewed through December 31, 2020. Interest payable related to this note was $0.2 million as of December 31, 2019. |
Schedule of Revenues and Purchases from Related Parties | We had the following related-party transactions for the years ended December 31 included in the corresponding captions in the accompanying Statements of Income: 2019 2018 2017 (in thousands) Revenues: Energy sold to Wyoming Electric $ 1,333 $ 2,064 $ 2,481 Rent from electric properties $ 3,583 $ 3,634 $ 3,680 Horizon Point shared facility revenue $ 12,026 $ 11,211 $ 1,420 Fuel and purchased power: Purchases from WRDC mine $ 17,041 $ 17,532 $ 15,948 Purchase of excess energy from Wyoming Electric $ 856 $ 511 $ 601 Purchase of renewable wind energy from Wyoming Electric - Happy Jack $ 1,968 $ 1,942 $ 1,924 Purchase of renewable wind energy from Wyoming Electric - Silver Sage $ 3,579 $ 3,586 $ 3,290 Gas transportation service agreement with Wyoming Electric for firm and interruptible gas transportation $ 309 $ 364 $ 393 |
Schedule of Related Party Corporate Support | We had the following corporate support for the years ended December 31: 2019 2018 2017 (in thousands) Corporate support services and fees from Parent, Black Hills Service Company and Black Hills Utility Holdings $ 39,667 $ 34,578 $ 27,869 |
Quarterly Historical Data (Un_2
Quarterly Historical Data (Unaudited) (Tables) | 12 Months Ended |
Dec. 31, 2019 | |
Selected Quarterly Financial Information [Abstract] | |
Schedule of Quarterly Financial Information | The following table sets forth selected unaudited historical operating results data for each quarter (in thousands): First Quarter Second Quarter Third Quarter Fourth Quarter 2019 Revenues $ 79,041 $ 69,246 $ 77,022 $ 65,910 Operating income $ 24,642 $ 17,310 $ 22,004 $ 19,981 Net income $ 15,497 $ 10,148 $ 13,743 $ 7,514 2018 Revenues $ 73,815 $ 70,676 $ 78,067 $ 75,522 Operating income $ 20,364 $ 19,495 $ 21,428 $ 17,048 Net income $ 11,760 $ 11,125 $ 13,317 $ 9,443 |
Business Description and Summ_4
Business Description and Summary of Significant Accounting Policies: Cash Equivalents (Details) - USD ($) | Dec. 31, 2019 | Dec. 31, 2018 |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | ||
Cash Equivalents | $ 0 | $ 0 |
Business Description and Summ_5
Business Description and Summary of Significant Accounting Policies: Accounts Receivable (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 |
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Less Allowance for doubtful accounts | $ (160) | $ (138) |
Accounts receivable, net | 25,532 | 28,431 |
Billed Revenues | ||
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Accounts receivable, trade | 14,778 | 16,236 |
Unbilled Revenues | ||
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Accounts receivable, trade | $ 10,914 | $ 12,333 |
Business Description and Summ_6
Business Description and Summary of Significant Accounting Policies: Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] | |||
Allowance for doubtful accounts, balance at beginning of year | $ 138 | $ 224 | $ 157 |
Additions charged to costs and expenses | 899 | 911 | 882 |
Deductions charged to costs and expenses | (877) | (997) | (815) |
Allowance for doubtful accounts, balance at end of year | $ 160 | $ 138 | $ 224 |
Business Description and Summ_7
Business Description and Summary of Significant Accounting Policies: Regulatory Assets and Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | ||
Regulatory Assets | $ 75,697 | $ 75,732 |
Regulatory Liabilities | $ 166,171 | $ 163,216 |
Business Description and Summ_8
Business Description and Summary of Significant Accounting Policies: Property, Plant and Equipment (Details) | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |||
Composite Depreciation Rate for Plants in Service | 2.20% | 2.30% | 2.10% |
Business Description and Summ_9
Business Description and Summary of Significant Accounting Policies: Accrued Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | ||
Accrued employee compensation, benefits and withholdings | $ 4,387 | $ 4,206 |
Accrued property taxes | 6,685 | 6,332 |
Accrued income taxes | 1,946 | 12,536 |
Customer deposits and prepayments | 5,486 | 5,204 |
Accrued interest | 4,935 | 4,627 |
Other (none of which is individually significant) | 2,053 | 1,288 |
Total accrued liabilities | $ 25,492 | $ 34,193 |
Business Description and Sum_10
Business Description and Summary of Significant Accounting Policies: Recently Adopted Accounting Standards (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Jan. 01, 2019 |
Operating Lease, Right-of-Use Asset | $ 14,374 | |
Accounting Standards Update 2016-02 | ||
Operating Lease, Right-of-Use Asset | $ 14,000 |
Revenue (Details)
Revenue (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended | |||||||||
Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Excluding Assessed Tax | $ 288,451 | $ 297,577 | |||||||||
Regulated Operating Revenue, Other | 2,768 | 503 | |||||||||
Revenue | $ 65,910 | $ 77,022 | $ 69,246 | $ 79,041 | $ 75,522 | $ 78,067 | $ 70,676 | $ 73,815 | 291,219 | 298,080 | $ 288,433 |
Services transferred over time | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Excluding Assessed Tax | 288,451 | 297,577 | |||||||||
Retail | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Excluding Assessed Tax | 202,569 | 197,184 | |||||||||
Wholesale | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Excluding Assessed Tax | 19,078 | 33,687 | |||||||||
Market Off-System Sales | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Excluding Assessed Tax | 16,475 | 17,691 | |||||||||
Transmission/Other | |||||||||||
Disaggregation of Revenue [Line Items] | |||||||||||
Revenue from Contract with Customer, Excluding Assessed Tax | $ 50,329 | $ 49,015 |
Property, Plant and Equipment_2
Property, Plant and Equipment (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2019 | Dec. 31, 2018 | |
Public Utilities, Property, Plant and Equipment, Net [Abstract] | ||
Total plant-in-service | $ 1,449,902 | $ 1,351,141 |
Construction work in progress | 44,768 | 29,904 |
Total electric plant | 1,494,670 | 1,381,045 |
Less accumulated depreciation and amortization | (400,054) | (376,160) |
Electric plant net of accumulated depreciation and amortization | $ 1,094,616 | 1,004,885 |
Remaining amortization period | 11 years | |
Electric Production | ||
Public Utilities, Property, Plant and Equipment, Net [Abstract] | ||
Production | $ 612,517 | $ 588,565 |
Electric Production | Weighted average useful life | ||
Public Utilities, Property, Plant and Equipment, Net [Abstract] | ||
Useful Life (in years) | 46 years | 46 years |
Electric Transmission | ||
Public Utilities, Property, Plant and Equipment, Net [Abstract] | ||
Transmission | $ 235,390 | $ 208,610 |
Electric Transmission | Weighted average useful life | ||
Public Utilities, Property, Plant and Equipment, Net [Abstract] | ||
Useful Life (in years) | 51 years | 48 years |
Electric Distribution | ||
Public Utilities, Property, Plant and Equipment, Net [Abstract] | ||
Distribution | $ 431,783 | $ 394,475 |
Electric Distribution | Weighted average useful life | ||
Public Utilities, Property, Plant and Equipment, Net [Abstract] | ||
Useful Life (in years) | 46 years | 45 years |
Plant Acquisition Adjustment | ||
Public Utilities, Property, Plant and Equipment, Net [Abstract] | ||
Plant acquisition adjustment | $ 4,870 | $ 4,870 |
Plant Acquisition Adjustment | Weighted average useful life | ||
Public Utilities, Property, Plant and Equipment, Net [Abstract] | ||
Useful Life (in years) | 32 years | 32 years |
General | ||
Public Utilities, Property, Plant and Equipment, Net [Abstract] | ||
General | $ 165,342 | $ 154,621 |
General | Weighted average useful life | ||
Public Utilities, Property, Plant and Equipment, Net [Abstract] | ||
Useful Life (in years) | 29 years | 28 years |
Jointly Owned Facilities (Detai
Jointly Owned Facilities (Details) $ in Thousands | Dec. 31, 2019USD ($)MW |
Wyodak Plant | |
Jointly Owned Utility Plant Interests [Line Items] | |
Proportionate Ownership Percentage | 20.00% |
Plant in Service | $ 116,074 |
Construction Work in Progress | 729 |
Less Accumulated Depreciation | (64,413) |
Jointly Owned Utility Plant, Net Ownership Amount | $ 52,390 |
Transmission Tie | |
Jointly Owned Utility Plant Interests [Line Items] | |
Proportionate Ownership Percentage | 35.00% |
Utility Plant, Megawatt Capacity | MW | 400 |
Plant in Service | $ 19,862 |
Construction Work in Progress | 4,161 |
Less Accumulated Depreciation | (6,612) |
Jointly Owned Utility Plant, Net Ownership Amount | $ 17,411 |
Transmission Tie | West to East Transmission Tie | |
Jointly Owned Utility Plant Interests [Line Items] | |
Utility Plant, Megawatt Capacity | MW | 200 |
Transmission Tie | East to West Transmission Tie | |
Jointly Owned Utility Plant Interests [Line Items] | |
Utility Plant, Megawatt Capacity | MW | 200 |
Wygen III Generating Facility | |
Jointly Owned Utility Plant Interests [Line Items] | |
Proportionate Ownership Percentage | 52.00% |
Plant in Service | $ 146,161 |
Construction Work in Progress | 400 |
Less Accumulated Depreciation | (25,518) |
Jointly Owned Utility Plant, Net Ownership Amount | $ 121,043 |
Cheyenne Prairie | |
Jointly Owned Utility Plant Interests [Line Items] | |
Electric Generation Capacity, Megawatts | MW | 95 |
Plant in Service | $ 92,684 |
Construction Work in Progress | 532 |
Less Accumulated Depreciation | (14,202) |
Jointly Owned Utility Plant, Net Ownership Amount | $ 79,014 |
Cheyenne Prairie | South Dakota Electric Portion | |
Jointly Owned Utility Plant Interests [Line Items] | |
Electric Generation Capacity, Megawatts | MW | 55 |
Cheyenne Prairie | Wyoming Electric Portion | Wyoming Electric | |
Jointly Owned Utility Plant Interests [Line Items] | |
Electric Generation Capacity, Megawatts | MW | 40 |
Long-term Debt (Details)
Long-term Debt (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Debt Instrument [Line Items] | |||
Unamortized Discount | $ (82) | $ (86) | |
Less unamortized deferred financing costs | (2,597) | (2,734) | |
Long-term Debt | 340,176 | 340,035 | |
Amortization of Financing Costs | $ 100 | 100 | $ 100 |
First Mortgage Bonds Due 2032 | |||
Debt Instrument [Line Items] | |||
Interest Rate, Stated Percentage | 7.23% | ||
Long-term Debt, Gross | $ 75,000 | 75,000 | |
First Mortgage Bonds Due 2039 | |||
Debt Instrument [Line Items] | |||
Interest Rate, Stated Percentage | 6.13% | ||
Long-term Debt, Gross | $ 180,000 | 180,000 | |
First Mortgage Bonds Due 2044 | |||
Debt Instrument [Line Items] | |||
Interest Rate, Stated Percentage | 4.43% | ||
Long-term Debt, Gross | $ 85,000 | 85,000 | |
Bonds Due 2024 | |||
Debt Instrument [Line Items] | |||
Variable Interest, Percentage Rate | 1.84% | ||
Long-term Debt, Gross | $ 2,855 | $ 2,855 |
Long-term Debt_ Schedule of Mat
Long-term Debt: Schedule of Maturities of Long-term Debt (Details) $ in Thousands | Dec. 31, 2019USD ($) |
Long-term Debt, Unclassified [Abstract] | |
2020 | $ 0 |
2021 | 0 |
2022 | 0 |
2023 | 0 |
2024 | 2,855 |
Thereafter | $ 340,000 |
Fair Value of Financial Instr_3
Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Cash and cash equivalents, at carrying value | $ 6 | $ 112 | $ 16 | $ 234 |
Notes payable to Parent | 25,000 | 0 | ||
Long-term debt, at carrying value | 340,176 | 340,035 | ||
Carrying Value | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Cash and cash equivalents, at carrying value | 6 | 112 | ||
Notes payable to Parent | 25,000 | 0 | ||
Long-term debt, at carrying value | 340,176 | 340,035 | ||
Fair Value | ||||
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||||
Cash and cash equivalents, at fair value | 6 | 112 | ||
Notes payable to Parent | 25,000 | 0 | ||
Long-term debt, at fair value | $ 458,286 | $ 412,894 |
Regulatory Matters_ Regulatory
Regulatory Matters: Regulatory Matters (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 |
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Assets | $ 75,697 | $ 75,732 | |
Regulatory Assets, Current | (21,588) | (19,052) | |
Regulatory assets, non-current | 54,109 | 56,680 | |
Regulatory Liabilities | 166,171 | 163,216 | |
Regulatory Liability, Current | (3,162) | (2,574) | |
Regulatory liabilities, non-current | 163,009 | 160,642 | |
Cost of removal for utility plant | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Liabilities | 57,318 | 52,366 | |
Employee benefit plans and related deferred taxes | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Liabilities | 7,023 | 7,518 | |
Deferred Income Tax Charges | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Liabilities | 98,228 | 100,276 | $ 101,000 |
TCJA revenue reserve | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Liabilities | 3,162 | 2,523 | |
Other regulatory liabilities | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Liabilities | 440 | 533 | |
Loss on reacquired debt | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Assets | 989 | 1,259 | |
Deferred taxes on AFUDC | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Assets | 4,927 | 5,020 | |
Employee benefit plans and related deferred taxes | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Assets | 20,661 | 19,868 | |
Deferred energy and fuel cost adjustments | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Assets | 23,203 | 20,334 | |
Deferred taxes on flow through accounting | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Assets | 9,801 | 8,749 | |
Decommissioning costs | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Assets | 6,211 | 8,196 | |
Vegetation management | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Assets | 8,062 | 10,366 | |
Other regulatory assets | |||
Schedule Of Regulatory Assets And Liabilities [Line Items] | |||
Regulatory Assets | $ 1,843 | $ 1,940 |
Regulatory Matters_ Settlement
Regulatory Matters: Settlement (Details) - South Dakota Public Utilities Commission (SDPUC) - USD ($) $ in Millions | Jul. 01, 2017 | Dec. 31, 2019 |
Public Utilities, Moratorium Period | 6 years | |
Public Utilities, Increase in Moratorium Period | 3 years | |
Application for Deferred Accounting Treatment Withdrawn | ||
Public Utilities, Development Costs Expensed | $ 5.4 | |
Settlement Amends Previous Moratorium Period | ||
Public Utilities, Moratorium Period | 6 years |
Regulatory Matters_ Renewable R
Regulatory Matters: Renewable Ready (Details) - Corriedale Wind Project $ in Millions | Dec. 31, 2019USD ($)utilityMW | Nov. 01, 2019MW |
Wyoming Public Service Commission (WPSC) | ||
Public Utilities Number of Electric Utilities Jointly Owning Wind Project | utility | 2 | |
Amount of Increase sought in Generating Capacity Under Environmental Improvement Adjustment Tariff | South Dakota Public Utilities Commission (SDPUC) | ||
Utility Plant, Megawatt Capacity | 12.5 | |
New Total Sought in Generating Capacity Under Environmental Improvement Adjustment Tariff | South Dakota Public Utilities Commission (SDPUC) | ||
Utility Plant, Megawatt Capacity | 32.5 | |
South Dakota Electric and Wyoming Electric | Wyoming Public Service Commission (WPSC) and South Dakota Public Utilities Commission (SDPUC) | ||
Public Utilities, Property, Plant and Equipment, Cost Of Plant Investment | $ | $ 79 | |
South Dakota Electric and Wyoming Electric | Approval Received | Wyoming Public Service Commission (WPSC) | ||
Public Utilities Increase (Decrease) in Utility Plant, Megawatt Capacity | 52.5 |
Regulatory Matters_ FERC Formul
Regulatory Matters: FERC Formula Rate (Details) - Federal Energy Regulatory Commission (FERC) Common Use System (CUS) - USD ($) $ in Millions | Jan. 01, 2019 | Dec. 31, 2019 | Dec. 31, 2018 |
Annual Revenue Requirement, as Required by the FERC Joint-Access Transmission Tariff | $ 1.9 | ||
Capital Addition Requirements by the FERC Joint-Access Transmission Tariff | $ 31 | $ 31 | $ 31 |
Leases Leases (Details)
Leases Leases (Details) $ in Thousands | 12 Months Ended |
Dec. 31, 2019USD ($) | |
Lessee, Lease, Description [Line Items] | |
Operating Lease, Cost | $ 908 |
Variable Lease, Cost | 137 |
Lease, Cost | $ 1,045 |
Minimum | |
Lessee, Lease, Description [Line Items] | |
Lessee, Operating Lease, Term of Contract | 1 year |
Maximum | |
Lessee, Lease, Description [Line Items] | |
Lessee, Operating Lease, Term of Contract | 30 years |
Leases Supplemental Balance She
Leases Supplemental Balance Sheet Information (Details) $ in Thousands | Dec. 31, 2019USD ($) |
Operating Lease, Right-of-Use Asset | $ 14,374 |
Other assets, non-current | |
Operating Lease, Right-of-Use Asset | 14,374 |
Accrued liabilities | |
Operating Lease, Liability, Current | 293 |
Other deferred credits and other liabilities | |
Operating Lease, Liability, Noncurrent | 14,105 |
Liabilities, Total | |
Operating Lease, Liability | $ 14,398 |
Leases Supplemental Cash Flow I
Leases Supplemental Cash Flow Information (Details) $ in Thousands | 12 Months Ended |
Dec. 31, 2019USD ($) | |
Leases [Abstract] | |
Operating Lease, Payments | $ 912 |
Right-of-use assets obtained in exchange for lease obligations: Operating leases | $ 0 |
Leases Weighted Average Informa
Leases Weighted Average Information (Details) | Dec. 31, 2019 |
Leases [Abstract] | |
Operating Lease, Weighted Average Remaining Lease Term | 30 years |
Operating Lease, Weighted Average Discount Rate, Percent | 4.30% |
Leases Future Minimum Payments
Leases Future Minimum Payments (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 |
Operating and Finance Lease Total [Abstract] | ||
2020 | $ 912 | |
2021 | 911 | |
2022 | 911 | |
2023 | 908 | |
2024 | 906 | |
Thereafter | 21,128 | |
Total lease payments | 25,676 | |
Less imputed interest | 11,278 | |
Prior Year End Operating Lease Future Minimum Payments [Abstract] | ||
2019 | $ 911 | |
2020 | 856 | |
2021 | 855 | |
2022 | 856 | |
2023 | 853 | |
Thereafter | 21,947 | |
Total lease payments | $ 26,278 | |
Liabilities, Total | ||
Operating and Finance Lease Total [Abstract] | ||
Present value of lease liabilities | $ 14,398 |
Income Taxes_ TCJA (Details)
Income Taxes: TCJA (Details) - USD ($) $ in Thousands | 24 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Tax Cuts and Jobs Act of 2017, Change in Tax Rate, Regulatory Liability | $ 103,000 | ||
Regulatory liability associated with TCJA related items | $ 166,171 | $ 163,216 | |
Deferred Income Tax Charges | |||
Regulatory liability associated with TCJA related items | 98,228 | 100,276 | $ 101,000 |
TCJA revenue reserve | |||
Regulatory liability associated with TCJA related items | 3,162 | $ 2,523 | |
Revenue Refunded To Customers As A Result Of The TCJA Tax Benefits | $ 3,100 |
Income Taxes_ Current and Defer
Income Taxes: Current and Deferred Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Income Tax Disclosure [Abstract] | |||
Current Federal Income Tax Expense | $ 13,782 | $ 5,454 | $ 13,124 |
Deferred Federal Income Tax Expense | (4,281) | 5,218 | 1,004 |
Total income tax expense | $ 9,501 | $ 10,672 | $ 14,128 |
Income Taxes_ Deferred Income T
Income Taxes: Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 |
Components of Deferred Tax Assets [Abstract] | ||
Regulatory liabilities | $ 25,623 | $ 25,587 |
Other | 9,128 | 4,721 |
Total deferred tax assets | 34,751 | 30,308 |
Components of Deferred Tax Liabilities [Abstract] | ||
Accelerated depreciation and other plant related differences | (125,138) | (125,594) |
Regulatory assets | (7,193) | (7,147) |
Deferred costs | (8,264) | (8,572) |
Other | (6,358) | (3,004) |
Total deferred tax liabilities | (146,953) | (144,317) |
Net deferred tax liability | $ (112,202) | $ (114,009) |
Income Taxes_ Effective Tax Rat
Income Taxes: Effective Tax Rate Differences from Statutory Tax Rates (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Income Tax Disclosure [Abstract] | |||
Federal statutory rate | 21.00% | 21.00% | 35.00% |
Amortization of excess deferred and investment tax credits | (3.00%) | (1.30%) | (0.10%) |
Flow through adjustments, percent | (1.50%) | (1.70%) | (1.80%) |
Tax reform | 0.00% | 2.50% | (9.20%) |
Other | 0.30% | (1.60%) | (2.30%) |
Effective Income Tax Rate | 16.80% | 18.90% | 21.60% |
Additional tax expense associated with TCJA related items | $ 0.9 |
Income Taxes_ Reconciliation of
Income Taxes: Reconciliation of unrecognized tax benefits (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2019 | Dec. 31, 2018 | |
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | ||
Beginning of Period | $ 249 | $ 302 |
Additions for current year tax positions | 0 | 0 |
Additions for prior year tax positions | 0 | 2 |
Reductions for prior year tax positions | (33) | (55) |
End of Period | $ 216 | $ 249 |
Other Comprehensive Income_ Oth
Other Comprehensive Income: Other Comprehensive Income (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended | ||||||||||
Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | Aug. 01, 2002 | |
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] | ||||||||||||
Interest expense | $ 23,972 | $ 22,545 | $ 22,421 | |||||||||
Income tax benefit (expense) | 9,501 | 10,672 | 14,128 | |||||||||
Net income | $ 7,514 | $ 13,743 | $ 10,148 | $ 15,497 | $ 9,443 | $ 13,317 | $ 11,125 | $ 11,760 | 46,902 | 45,645 | $ 51,298 | |
First Mortgage Bonds Due 2032 | ||||||||||||
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] | ||||||||||||
Derivative, Notional Amount | $ 50,000 | 50,000 | ||||||||||
Realized Loss Included Accumulated Other Comprehensive Income (Loss) | $ 1,800 | |||||||||||
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges | Reclassification out of Accumulated Other Comprehensive Income | ||||||||||||
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] | ||||||||||||
Income tax benefit (expense) | 132 | 13 | ||||||||||
Net income | 68 | (51) | ||||||||||
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges | Reclassification out of Accumulated Other Comprehensive Income | Interest Rate Contract | ||||||||||||
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] | ||||||||||||
Interest expense | (64) | (64) | ||||||||||
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) | Reclassification out of Accumulated Other Comprehensive Income | ||||||||||||
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] | ||||||||||||
Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses | (65) | (103) | ||||||||||
Accumulated Defined Benefit Plans Adjustment | Reclassification out of Accumulated Other Comprehensive Income | ||||||||||||
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] | ||||||||||||
Income tax benefit (expense) | 166 | 22 | ||||||||||
Net income | $ 101 | $ (81) |
Other Comprehensive Income_ Acc
Other Comprehensive Income: Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2019 | Dec. 31, 2018 | |
Accumulated Other Comprehensive Income (Loss) [Roll Forward] | ||
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | $ (891) | $ (1,258) |
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | (1,380) | (891) |
Interest Rate Swaps, Cash Flow Hedges, AOCI | Interest Rate Swaps | ||
Accumulated Other Comprehensive Income (Loss) [Roll Forward] | ||
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | (500) | (551) |
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax | 0 | 0 |
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | (568) | (500) |
Employee Benefit Plans, AOCI | ||
Accumulated Other Comprehensive Income (Loss) [Roll Forward] | ||
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start | (391) | (707) |
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax | (320) | 235 |
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End | (812) | (391) |
Accumulated Other Comprehensive Income (Loss) | ||
Accumulated Other Comprehensive Income (Loss) [Roll Forward] | ||
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax | (320) | 235 |
Reclassification out of Accumulated Other Comprehensive Income | Interest Rate Swaps, Cash Flow Hedges, AOCI | Interest Rate Swaps | ||
Accumulated Other Comprehensive Income (Loss) [Roll Forward] | ||
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax | (68) | 51 |
Reclassification out of Accumulated Other Comprehensive Income | Employee Benefit Plans, AOCI | ||
Accumulated Other Comprehensive Income (Loss) [Roll Forward] | ||
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax | (101) | 81 |
Reclassification out of Accumulated Other Comprehensive Income | Accumulated Other Comprehensive Income (Loss) | ||
Accumulated Other Comprehensive Income (Loss) [Roll Forward] | ||
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax | $ (169) | $ 132 |
Supplemental Cash Flow Inform_3
Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] | |||
Accrued property, plant and equipment purchases at December 31 | $ 12,305 | $ 15,180 | $ 6,565 |
Interest and Income Taxes (Paid) Refunded, Cash Flow Information [Abstract] | |||
Interest (net of amounts capitalized) | (21,909) | (21,988) | (21,517) |
Income taxes (paid), net | (24,372) | (10,394) | (12,719) |
Subsidiary of Common Parent | |||
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] | |||
Non-cash decrease to money pool note receivable, net | 0 | (36,000) | (42,000) |
Parent Company | |||
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] | |||
Non-cash dividend to Parent | $ 0 | $ 36,000 | $ 42,000 |
Employee Benefit Plans_ Narrati
Employee Benefit Plans: Narrative (Details) | 12 Months Ended | |
Dec. 31, 2019 | Dec. 31, 2018 | |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Maximum Annual Contribution Per Employee, Percent | 50.00% | |
Employers Matching Contribution, Annual Vesting Percentage | 20.00% | |
Defined Contribution Plan, Employee Vesting Period | 5 years | |
Target Plan Asset Allocations, percent | 100.00% | 100.00% |
Equity Securities | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Target Plan Asset Allocations, percent | 20.00% | 17.00% |
Fixed Income Funds | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Target Plan Asset Allocations, percent | 71.00% | 71.00% |
Minimum | Defined Benefit Pension Plan | Equity Securities | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Target Plan Asset Allocations, percent | 29.00% | |
Minimum | Defined Benefit Pension Plan | Fixed Income Funds | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Target Plan Asset Allocations, percent | 63.00% | |
Maximum | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Employers Matching Contribution, Annual Vesting Percentage | 100.00% | |
Maximum | Defined Benefit Pension Plan | Equity Securities | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Target Plan Asset Allocations, percent | 37.00% | |
Maximum | Defined Benefit Pension Plan | Fixed Income Funds | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Target Plan Asset Allocations, percent | 71.00% |
Employee Benefit Plans_ Plan As
Employee Benefit Plans: Plan Assets Allocation (Details) | Dec. 31, 2019 | Dec. 31, 2018 |
Defined Benefit Plan Disclosure [Line Items] | ||
Target Plan Asset Allocations, percent | 100.00% | 100.00% |
Equity Securities | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Target Plan Asset Allocations, percent | 20.00% | 17.00% |
Real Estate | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Target Plan Asset Allocations, percent | 3.00% | 4.00% |
Fixed Income Funds | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Target Plan Asset Allocations, percent | 71.00% | 71.00% |
Cash and Cash Equivalents | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Target Plan Asset Allocations, percent | 2.00% | 3.00% |
Hedge Funds | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Target Plan Asset Allocations, percent | 4.00% | 5.00% |
Employee Benefit Plans_ Plan Co
Employee Benefit Plans: Plan Contributions (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2019 | Dec. 31, 2018 | |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year | $ 1,700 | |
Defined Benefit Pension Plan | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Defined Benefit Pension Plan - Employer contributions | 1,753 | $ 1,795 |
Non-pension Defined Benefit Postretirement Healthcare Plan | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Defined Benefit Pension Plan - Employer contributions | 643 | 268 |
Defined Benefit Plans - Other, Employer Contributions | 739 | 388 |
Supplemental Non-qualified Defined Benefit Retirement Plans | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Defined Benefit Pension Plan - Employer contributions | 266 | 238 |
Defined Benefit Plans - Other, Employer Contributions | 266 | 238 |
Company Retirement Contribution | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Defined Contribution Plans, Contributions by Employer | 888 | 876 |
Matching Contributions | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Defined Contribution Plans, Contributions by Employer | $ 1,275 | $ 1,272 |
Employee Benefit Plans_ Fair Va
Employee Benefit Plans: Fair Value Measurements (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Minimum | Hedge Funds | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period | 10 days | ||
Maximum | Hedge Funds | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period | 30 days | ||
Hedge Funds | Minimum | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Percentage Of Monthly Redemption | 20.00% | ||
Hedge Funds | Maximum | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Percentage Of Quarterly Redemption | 100.00% | ||
Defined Benefit Pension Plan | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | $ 60,190 | $ 54,664 | $ 59,884 |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 60,190 | 54,664 | |
Defined Benefit Plan, Fair Value of Plan Assets, Excluding Net Asset Value investments | 55,507 | 50,141 | |
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets | 4,683 | 4,523 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fixed Income Funds | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 8 | 261 | |
Defined Benefit Plan, Fair Value of Plan Assets, Excluding Net Asset Value investments | 8 | 261 | |
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Common Collective Trust, Cash And Cash Equivalents | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 978 | 1,388 | |
Defined Benefit Plan, Fair Value of Plan Assets, Excluding Net Asset Value investments | 978 | 1,388 | |
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Common Collective Trust - Equity | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 12,072 | 9,436 | |
Defined Benefit Plan, Fair Value of Plan Assets, Excluding Net Asset Value investments | 12,072 | 9,436 | |
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Common Collective Trust - Fixed Income | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 42,449 | 39,047 | |
Defined Benefit Plan, Fair Value of Plan Assets, Excluding Net Asset Value investments | 42,449 | 39,047 | |
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Common Collective Trust - Real Estate | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 1,974 | 1,905 | |
Defined Benefit Plan, Fair Value of Plan Assets, Excluding Net Asset Value investments | 0 | 9 | |
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets | 1,974 | 1,896 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Hedge Funds | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 2,709 | 2,627 | |
Defined Benefit Plan, Fair Value of Plan Assets, Excluding Net Asset Value investments | 0 | 0 | |
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets | 2,709 | 2,627 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 1 | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 1 | Fixed Income Funds | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 1 | Common Collective Trust, Cash And Cash Equivalents | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 1 | Common Collective Trust - Equity | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 1 | Common Collective Trust - Fixed Income | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 1 | Common Collective Trust - Real Estate | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 1 | Hedge Funds | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 2 | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 55,507 | 50,141 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 2 | Fixed Income Funds | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 8 | 261 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 2 | Common Collective Trust, Cash And Cash Equivalents | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 978 | 1,388 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 2 | Common Collective Trust - Equity | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 12,072 | 9,436 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 2 | Common Collective Trust - Fixed Income | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 42,449 | 39,047 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 2 | Common Collective Trust - Real Estate | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 9 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 2 | Hedge Funds | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 3 | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 3 | Fixed Income Funds | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 3 | Common Collective Trust, Cash And Cash Equivalents | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 3 | Common Collective Trust - Equity | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 3 | Common Collective Trust - Fixed Income | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 3 | Common Collective Trust - Real Estate | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | 0 | 0 | |
Fair Value, Measurements, Recurring | Defined Benefit Pension Plan | Fair Value, Level 3 | Hedge Funds | |||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
Total investments measured at fair value | $ 0 | $ 0 |
Employee Benefit Plans_ Changes
Employee Benefit Plans: Changes in Benefit Obligations (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Defined Benefit Pension Plan | |||
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] | |||
Projected benefit obligation at beginning of year | $ 61,919 | $ 67,562 | |
Service cost | 365 | 516 | $ 545 |
Interest cost | 2,410 | 2,194 | 2,341 |
Actuarial loss (gain) | 7,482 | (2,878) | |
Benefits paid | (5,234) | (3,562) | |
Plan participants transfer to affiliate | 119 | (1,913) | |
Plan participants’ contributions | 0 | 0 | |
Projected benefit obligation at end of year | 67,061 | 61,919 | 67,562 |
Supplemental Non-qualified Defined Benefit Retirement Plans | |||
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] | |||
Projected benefit obligation at beginning of year | 2,992 | 3,418 | |
Service cost | 0 | 0 | 0 |
Interest cost | 114 | 108 | 116 |
Actuarial loss (gain) | 406 | (296) | |
Benefits paid | (266) | (238) | |
Plan participants transfer to affiliate | 0 | 0 | |
Plan participants’ contributions | 0 | 0 | |
Projected benefit obligation at end of year | 3,246 | 2,992 | 3,418 |
Non-pension Defined Benefit Postretirement Healthcare Plan | |||
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] | |||
Projected benefit obligation at beginning of year | 5,055 | 5,970 | |
Service cost | 148 | 193 | 206 |
Interest cost | 186 | 179 | 176 |
Actuarial loss (gain) | 507 | (889) | |
Benefits paid | (739) | (389) | |
Plan participants transfer to affiliate | (77) | (129) | |
Plan participants’ contributions | 96 | 120 | |
Projected benefit obligation at end of year | $ 5,176 | $ 5,055 | $ 5,970 |
Employee Benefit Plans_ Chang_2
Employee Benefit Plans: Changes in Plan Assets (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2019 | Dec. 31, 2018 | |
Defined Benefit Pension Plan | ||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||
Beginning market value of plan assets | $ 54,664 | $ 59,884 |
Investment income (loss) | 8,902 | (1,884) |
Employer contributions | 1,753 | 1,795 |
Retiree contributions | 0 | 0 |
Benefits paid | (5,234) | (3,563) |
Asset transfer to affiliate | 105 | (1,568) |
Ending fair value of plan assets | 60,190 | 54,664 |
Supplemental Non-qualified Defined Benefit Retirement Plans | ||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||
Beginning market value of plan assets | 0 | 0 |
Investment income (loss) | 0 | 0 |
Employer contributions | 266 | 238 |
Retiree contributions | 0 | 0 |
Benefits paid | (266) | (238) |
Asset transfer to affiliate | 0 | 0 |
Ending fair value of plan assets | 0 | 0 |
Non-pension Defined Benefit Postretirement Healthcare Plan | ||
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||
Beginning market value of plan assets | 0 | 0 |
Investment income (loss) | 0 | 0 |
Employer contributions | 643 | 268 |
Retiree contributions | 96 | 120 |
Benefits paid | (739) | (388) |
Asset transfer to affiliate | 0 | 0 |
Ending fair value of plan assets | $ 0 | $ 0 |
Employee Benefit Plans_ Amounts
Employee Benefit Plans: Amounts Recognized in the Balance Sheet (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Non-current liability | $ 14,636 | $ 14,606 |
Regulatory Liabilities | 166,171 | 163,216 |
Defined Benefit Pension Plan | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Regulatory asset | 20,117 | 19,099 |
Current liability | 0 | 0 |
Non-current liability | 7,121 | 7,255 |
Regulatory Liabilities | 0 | 0 |
Supplemental Non-qualified Defined Benefit Retirement Plans | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Regulatory asset | 0 | 0 |
Current liability | 321 | 230 |
Non-current liability | 2,925 | 2,762 |
Regulatory Liabilities | 0 | 0 |
Non-pension Defined Benefit Postretirement Healthcare Plan | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Regulatory asset | 0 | 0 |
Current liability | 586 | 466 |
Non-current liability | 4,590 | 4,589 |
Regulatory Liabilities | $ 1,675 | $ 2,441 |
Employee Benefit Plans_ Accumul
Employee Benefit Plans: Accumulated Benefit Obligation (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 |
Defined Benefit Pension Plan | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Accumulated benefit obligation | $ 65,225 | $ 59,987 |
Supplemental Non-qualified Defined Benefit Retirement Plans | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Accumulated benefit obligation | 3,246 | 2,992 |
Non-pension Defined Benefit Postretirement Healthcare Plan | ||
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | ||
Accumulated benefit obligation | $ 5,176 | $ 5,055 |
Employee Benefit Plans_ Compone
Employee Benefit Plans: Components of Net Periodic Expense (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Defined Benefit Pension Plan | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Service cost | $ 365 | $ 516 | $ 545 |
Interest cost | 2,410 | 2,194 | 2,341 |
Expected return on assets | (3,405) | (3,545) | (3,591) |
Amortization of prior service cost (credits) | 10 | 43 | 43 |
Recognized net actuarial loss (gain) | 1,221 | 2,063 | 1,230 |
Net periodic expense | 601 | 1,271 | 568 |
Supplemental Non-qualified Defined Benefit Retirement Plans | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Service cost | 0 | 0 | 0 |
Interest cost | 114 | 108 | 116 |
Expected return on assets | 0 | 0 | 0 |
Amortization of prior service cost (credits) | 0 | 0 | 0 |
Recognized net actuarial loss (gain) | 65 | 103 | 87 |
Net periodic expense | 179 | 211 | 203 |
Non-pension Defined Benefit Postretirement Healthcare Plan | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Service cost | 148 | 193 | 206 |
Interest cost | 186 | 179 | 176 |
Expected return on assets | 0 | 0 | 0 |
Amortization of prior service cost (credits) | (336) | (336) | (336) |
Recognized net actuarial loss (gain) | 0 | 0 | 0 |
Net periodic expense | $ (2) | $ 36 | $ 46 |
Employee Benefit Plans_ Accum_2
Employee Benefit Plans: Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 |
Defined Benefit Pension Plan | ||
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract] | ||
Net (gain) loss | $ 0 | $ 0 |
Total AOCI | 0 | 0 |
Supplemental Non-qualified Defined Benefit Retirement Plans | ||
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract] | ||
Net (gain) loss | 812 | 391 |
Total AOCI | 812 | 391 |
Non-pension Defined Benefit Postretirement Healthcare Plan | ||
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract] | ||
Net (gain) loss | 0 | 0 |
Total AOCI | $ 0 | $ 0 |
Employee Benefit Plans_ Defined
Employee Benefit Plans: Defined Benefit Plans Assumptions (Details) | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Healthcare trend rate pre-65 | |||
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract] | |||
Trend for next year | 6.40% | 6.70% | |
Ultimate trend rate | 4.50% | 4.50% | |
Year Ultimate Trend Reached | 2027 | 2027 | |
Healthcare trend rate post-65 | |||
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract] | |||
Trend for next year | 4.92% | 4.94% | |
Ultimate trend rate | 4.50% | 4.50% | |
Year Ultimate Trend Reached | 2028 | 2026 | |
Defined Benefit Pension Plan | |||
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract] | |||
Discount rate | 3.27% | 4.40% | 3.71% |
Rate of increase in compensation levels | 3.49% | 3.52% | 3.43% |
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] | |||
Discount rate | 4.40% | 3.71% | 4.27% |
Expected long-term rate of return on assets | 6.00% | 6.25% | 6.75% |
Rate of increase in compensation levels | 3.52% | 3.43% | 3.47% |
Defined Benefit Plan Assumptions Used In Calculating Net Periodic Benefit Cost Expected Rate of Return On Assets For Next Fiscal Year | 5.25% | ||
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract] | |||
Trend for next year | 3.27% | ||
Supplemental Non-qualified Defined Benefit Retirement Plans | |||
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract] | |||
Discount rate | 3.10% | 4.30% | 3.62% |
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] | |||
Discount rate | 4.30% | 3.62% | 4.12% |
Non-pension Defined Benefit Postretirement Healthcare Plan | |||
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract] | |||
Discount rate | 3.15% | 4.28% | 3.60% |
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] | |||
Discount rate | 4.28% | 3.60% | 3.84% |
Expected long-term rate of return on assets | 3.00% | 3.93% |
Employee Benefit Plans_ Project
Employee Benefit Plans: Projected Benefit Plan Payments (Details) $ in Thousands | Dec. 31, 2019USD ($) |
Defined Benefit Pension Plan | |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | |
2020 | $ 3,620 |
2021 | 3,766 |
2022 | 3,833 |
2023 | 3,951 |
2024 | 4,022 |
2025-2028 | 19,882 |
Supplemental Non-qualified Defined Benefit Retirement Plans | |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | |
2020 | 321 |
2021 | 317 |
2022 | 315 |
2023 | 311 |
2024 | 308 |
2025-2028 | 1,142 |
Non-pension Defined Benefit Postretirement Healthcare Plan | |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | |
2020 | 586 |
2021 | 622 |
2022 | 591 |
2023 | 522 |
2024 | 474 |
2025-2028 | $ 1,853 |
Commitment and Contingencies_ P
Commitment and Contingencies: Power Purchase and Transmission Services Agreements (Details) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019USD ($)MW | Dec. 31, 2018USD ($) | Dec. 31, 2017USD ($) | |
PacifiCorp Purchase Power Agreement | |||
Long-term Purchase Commitment [Line Items] | |||
Number of Megawatts Capacity Purchased | MW | 50 | ||
Cost of Goods and Services Sold | $ 7,477 | $ 13,681 | $ 13,218 |
PacifiCorp Transmission | |||
Long-term Purchase Commitment [Line Items] | |||
Number of Megawatts Capacity Purchased | MW | 50 | ||
Cost of Goods and Services Sold | $ 1,741 | 1,742 | 1,671 |
Platte River Power Authority Wind Power Agreement | |||
Long-term Purchase Commitment [Line Items] | |||
Number of Megawatts Capacity Purchased | MW | 12 | ||
Cost of Goods and Services Sold | $ 688 | 223 | 0 |
Thunder Creek - Gas Transport Capacity | |||
Long-term Purchase Commitment [Line Items] | |||
Cost of Goods and Services Sold | $ 422 | $ 633 | $ 633 |
Commitment and Contingencies_ F
Commitment and Contingencies: Future Contractual Obligations (Details) $ in Thousands | Dec. 31, 2019USD ($) |
Commitments and Contingencies Disclosure [Abstract] | |
2020 | $ 6,531 |
2021 | 6,203 |
2022 | 6,203 |
2023 | 6,203 |
2024 | 0 |
Thereafter | $ 0 |
Commitment and Contingencies__2
Commitment and Contingencies: Power Sales Agreements (Details) | Dec. 31, 2019MW |
M D U, Montana Dakota Utilities | Wygen III Generating Facility | |
Other Commitments [Line Items] | |
Number of Megawatts Sold Under Long-Term Contract | 25 |
City Of Gillette | |
Other Commitments [Line Items] | |
Number of Megawatts Sold Under Long-Term Contract | 23 |
Purchase Power Contract, MEAN | |
Other Commitments [Line Items] | |
Number of Megawatts Sold Under Long-Term Contract | 20 |
2019-2020 | 15 |
2020-2022 | 15 |
2022-2023 | 15 |
2023-2028 | 10 |
Purchase Power Contract, MEAN | Wygen III Generating Facility | |
Other Commitments [Line Items] | |
2019-2020 | 10 |
2020-2022 | 7 |
2022-2023 | 8 |
2023-2028 | 5 |
Purchase Power Contract, MEAN | Neil Simpson I I | |
Other Commitments [Line Items] | |
2019-2020 | 5 |
2020-2022 | 8 |
2022-2023 | 7 |
2023-2028 | 5 |
Macquarie Energy, LLC Supply Agreement | |
Other Commitments [Line Items] | |
Number of Megawatts Sold Under Long-Term Contract | 50 |
Maximum | M D U, Montana Dakota Utilities | |
Other Commitments [Line Items] | |
Number of Megawatts Sold Under Long-Term Contract | 50 |
Related-Party Transactions_ Non
Related-Party Transactions: Non-Cash Dividend to Parent (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Subsidiary of Common Parent | |||
Related Party Transaction [Line Items] | |||
Non-cash decrease to money pool note receivable, net | $ 0 | $ (36,000) | $ (42,000) |
Parent Company | |||
Related Party Transaction [Line Items] | |||
Non-cash dividend to Parent | $ 0 | $ 36,000 | $ 42,000 |
Related-Party Transactions_ Rec
Related-Party Transactions: Receivables and Payables (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 |
Related Party Transactions [Abstract] | ||
Accounts receivable from affiliates | $ 7,838 | $ 8,119 |
Accounts payable to affiliates | $ 32,121 | $ 25,804 |
Related-Party Transactions_ Mon
Related-Party Transactions: Money Pool Notes Receivable and Notes Payable (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Related Party Transaction [Line Items] | |||
Related Party Transaction, Interest Rate at the End of the Period | 2.21% | ||
Money pool notes payable | $ 57,585 | $ 38,690 | |
Parent Company | |||
Related Party Transaction [Line Items] | |||
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | 1.00% | ||
Interest expense, related party | $ (1,200) | (1,300) | $ (1,400) |
Utility Money Pool | |||
Related Party Transaction [Line Items] | |||
Interest expense, related party | $ (775) | $ (401) | |
Interest income, related party | $ 272 |
Related-Party Transactions_ Not
Related-Party Transactions: Notes Payable to Parent (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2019 | Dec. 31, 2018 | |
Related Party Transaction [Line Items] | ||
Notes payable to Parent | $ 25,000 | $ 0 |
Parent Company | ||
Related Party Transaction [Line Items] | ||
Notes payable to Parent | $ 25,000 | $ 0 |
Related Party Transaction, Rate | 4.51% | |
Interest Payable Related Party | $ 200 |
Related-Party Transactions_ Int
Related-Party Transactions: Interest Expense Allocation from Parent (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Parent Company | |||
Related Party Transaction [Line Items] | |||
Interest expense, related party | $ 1.2 | $ 1.3 | $ 1.4 |
Related-Party Transactions_ Oth
Related-Party Transactions: Other Balances and Transactions (Details) | 12 Months Ended |
Dec. 31, 2019Number_Of_Ground_Lease_ExtensionMW | |
Wygen III Ground Lease with WRDC | |
Related Party Transaction [Line Items] | |
Number of 20 Year Terms | Number_Of_Ground_Lease_Extension | 3 |
Lessee, Operating Lease, Renewal Term | 20 years |
Wyoming Electric | Happy Jack Wind Purchase Power Agreement | |
Related Party Transaction [Line Items] | |
Number of Megawatts Capacity Purchased | 30 |
Wyoming Electric | Happy Jack Wind Purchase Power Agreement | Subsidiary of Common Parent | |
Related Party Transaction [Line Items] | |
Long-term Contract for Purchase of Electric Power, Share of Plant Output Being Purchased | 50.00% |
Wyoming Electric | Silver Sage Wind Power Purchase Agreement | |
Related Party Transaction [Line Items] | |
Number of Megawatts Capacity Purchased | 30 |
Wyoming Electric | Silver Sage Wind Power Purchase Agreement | Subsidiary of Common Parent | |
Related Party Transaction [Line Items] | |
Number of Megawatts Sold | 20 |
Related-Party Transactions_ Rel
Related-Party Transactions: Related-Party Gas Transportation Service Agreement (Details) | 12 Months Ended |
Dec. 31, 2019 | |
Purchase Of Natural Gas, Wyoming Gas | Subsidiary of Common Parent | |
Related Party Transaction [Line Items] | |
Long-term Purchase Commitment, Period | 40 years |
Related-Party Transactions_ R_2
Related-Party Transactions: Related-Party Revenue and Purchases (Details) - Subsidiary of Common Parent - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Purchase Of Natural Gas, Cheyenne Light | |||
Related Party Transaction [Line Items] | |||
Costs and Expenses, Related Party | $ 309 | $ 364 | $ 393 |
Coal, Purchased | |||
Related Party Transaction [Line Items] | |||
Costs and Expenses, Related Party | 17,041 | 17,532 | 15,948 |
Purchase of Excess Energy, Wyoming Electric | |||
Related Party Transaction [Line Items] | |||
Costs and Expenses, Related Party | 856 | 511 | 601 |
Happy Jack Wind Purchase Power Agreement | |||
Related Party Transaction [Line Items] | |||
Costs and Expenses, Related Party | 1,968 | 1,942 | 1,924 |
Silver Sage Wind Power Purchase Agreement | |||
Related Party Transaction [Line Items] | |||
Costs and Expenses, Related Party | 3,579 | 3,586 | 3,290 |
Horizon Point Shared Facility Revenues | |||
Related Party Transaction [Line Items] | |||
Revenue from Related Parties | 12,026 | 11,211 | 1,420 |
Energy sold to Wyoming Electric | |||
Related Party Transaction [Line Items] | |||
Revenue from Related Parties | 1,333 | 2,064 | 2,481 |
Lease Agreements | |||
Related Party Transaction [Line Items] | |||
Revenue from Related Parties | $ 3,583 | $ 3,634 | $ 3,680 |
Related-Party Transactions_ R_3
Related-Party Transactions: Related-Party Corporate Support (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Allocated Costs From Related Parties | Subsidiary of Common Parent | |||
Related Party Transaction [Line Items] | |||
Costs and Expenses, Related Party | $ 39,667 | $ 34,578 | $ 27,869 |
Quarterly Financial information
Quarterly Financial information Data (Unaudited) (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended | |||||||||
Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
Selected Quarterly Financial Information [Abstract] | |||||||||||
Revenue | $ 65,910 | $ 77,022 | $ 69,246 | $ 79,041 | $ 75,522 | $ 78,067 | $ 70,676 | $ 73,815 | $ 291,219 | $ 298,080 | $ 288,433 |
Operating income | 19,981 | 22,004 | 17,310 | 24,642 | 17,048 | 21,428 | 19,495 | 20,364 | 83,937 | 78,335 | 83,826 |
Net income | $ 7,514 | $ 13,743 | $ 10,148 | $ 15,497 | $ 9,443 | $ 13,317 | $ 11,125 | $ 11,760 | $ 46,902 | $ 45,645 | $ 51,298 |