Black Hills Power 10-Q 12 May 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	3 Months Ended
	Mar. 31, 2016	Apr. 30, 2016
Document Information [Line Items]
Entity Registrant Name	BLACK HILLS POWER INC
Entity Central Index Key	12,400
Document Type	10-Q
Document Period End Date	Mar. 31, 2016
Amendment Flag	false
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		23,416,396

Condensed Statements of Income

Condensed Statements of Income and Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Revenue	$ 68,642	$ 70,283
Operating expenses:
Fuel, purchased power and natural gas	20,730	22,104
Operations and maintenance	17,031	17,091
Depreciation and amortization	8,612	8,125
Taxes - property	1,489	1,473
Total operating expenses	47,862	48,793
Operating income	20,780	21,490
Other income (expense):
Interest expense	(5,454)	(5,692)
AFUDC - borrowed	223	39
Interest income	202	104
AFUDC - equity	423	70
Other income (expense), net	74	35
Total other income (expense)	(4,532)	(5,444)
Income from continuing operations before income taxes	16,248	16,046
Income tax expense	(5,062)	(5,643)
Net Income	11,186	10,403
Other comprehensive income (loss):
Reclassification adjustments of cash flow hedges settled and included in net income (net of tax (expense) benefit of $(6) and $336 for the three months ended March 31, 2016 and 2015)	10	352
Reclassification adjustment of benefit plan liability - net gain (loss) (net of tax (expense) benefit of $(7) and $(8) for the three months ended March 31, 2016 and 2015)	14	15
Other comprehensive income	24	367
Comprehensive income	$ 11,210	$ 10,770

Condensed Statements of Income3

Condensed Statements of Income and Comprehensive Income OCI Parenthetical - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Reclassification adjustment of cash flow hedges settled, (tax) benefit	$ (6)	$ 336
Reclassification adjustment of benefit and other postretirement plans included in net income, (tax) benefit	$ (7)	$ (8)

Condensed Balance Sheets

Condensed Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 28,999	$ 7,559
Receivables - customers, net	27,140	27,856
Receivables - affiliates	8,391	5,747
Other receivables, net	242	236
Money pool notes receivable, net	50,630	76,813
Materials, supplies and fuel	22,891	24,282
Regulatory assets, current	18,550	14,096
Other, current assets	4,995	43,118
Total current assets	161,838	199,707
Investments	4,756	4,725
Property, plant and equipment	1,175,978	1,166,126
Less accumulated depreciation and amortization	(329,494)	(326,074)
Total property, plant and equipment, net	846,484	840,052
Other assets:
Regulatory assets, non-current	71,125	71,717
Other, non-current assets	345	3,292
Total other assets	71,470	75,009
TOTAL ASSETS	1,084,548	1,119,493
Current liabilities:
Accounts payable	21,508	21,297
Accounts payable - affiliates	27,148	30,032
Accrued liabilities	22,014	69,454
Regulatory liabilities, current	34	0
Total current liabilities	70,704	120,783
Long-term debt, net of current maturities	339,651	342,756
Deferred credits and other liabilities:
Deferred income tax liability, net, non-current	207,508	188,961
Regulatory liabilities, non-current	52,644	51,583
Benefit plan liabilities	20,363	20,033
Other, non-current liabilities	2,989	3,398
Total deferred credits and other liabilities	$ 283,504	$ 263,975
Commitments and contingencies (Notes 4, 5 and 8)
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	328,981	330,295
Accumulated other comprehensive loss	(1,283)	(1,307)
Total stockholder’s equity	390,689	391,979
TOTAL LIABILITIES AND STOCKHOLDER’S EQUITY	$ 1,084,548	$ 1,119,493

Balance Sheet Parentheticals

Balance Sheet Parentheticals - $ / shares	Mar. 31, 2016	Dec. 31, 2015
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

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating activities:
Net income	$ 11,186	$ 10,403
Adjustments to reconcile net income to net cash provided by operating activities-
Depreciation and amortization	8,612	8,125
Deferred income tax	18,076	4,962
Employee benefits	443	601
AFUDC - equity	(423)	(70)
Other adjustments, net	296	85
Change in operating assets and liabilities -
Accounts receivable and other current assets	(2,041)	7,951
Accounts payable and other current liabilities	(5,725)	(10,237)
Regulatory assets - current	(4,193)	(2,722)
Regulatory liabilities - current	0	3,715
Other operating activities, net	481	(719)
Net cash provided by (used in) operating activities	26,712	22,094
Investing activities:
Property, plant and equipment additions	(18,928)	(8,697)
Change in money pool notes receivable, net	13,683	35,111
Other investing activities	(27)	(44)
Net cash provided by (used in) investing activities	(5,272)	26,370
Financing activities:
Net cash provided by (used in) financing activities	0	0
Net change in cash and cash equivalents	21,440	48,464
Cash and Cash Equivalents:
Cash and cash equivalents, beginning of period	7,559	6,620
Cash and cash equivalents, end of period	$ 28,999	$ 55,084

Management's Statement_

Management's Statement:	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Management's Statement	MANAGEMENT’S STATEMENT The unaudited condensed financial statements included herein have been prepared by Black Hills Power, Inc. (the “Company,” “we,” “us,” or “our”), pursuant to the rules and regulations of the SEC. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted pursuant to such rules and regulations; however, we believe that the footnotes adequately disclose the information presented. These condensed financial statements should be read in conjunction with the financial statements and the notes thereto, included in our 2015 Annual Report on Form 10-K filed with the SEC. Accounting methods historically employed require certain estimates as of interim dates. The information furnished in the accompanying condensed financial statements reflects all adjustments, including accruals, which are, in the opinion of management, necessary for a fair presentation of the March 31, 2016 , December 31, 2015 and March 31, 2015 financial information and are of a normal recurring nature. The results of operations for the three months ended March 31, 2016 and March 31, 2015 , and our financial condition as of March 31, 2016 and December 31, 2015 are not necessarily indicative of the results of operations and financial condition to be expected as of or for any other period. Recently Issued and Adopted Accounting Standards Leases, ASU 2016-02 In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which supersedes ASC 840, Leases . This ASU requires lessees to recognize a right-of-use asset and lease liability for all leases with terms of more than 12 months. Lessees are permitted to make an accounting policy election to not recognize the asset and liability for leases with a term of 12 months or less. The ASU does not significantly change the lessees’ recognition, measurement and presentation of expenses and cash flows from the previous accounting standard. Lessors’ accounting under the ASC is largely unchanged from the previous accounting standard. In addition, the ASU expands the disclosure requirements of lease arrangements. Lessees and lessors will use a modified retrospective transition approach, which includes a number of practical expedients. The guidance is effective for the Company beginning after December 15, 2019. Early adoption is permitted. We are currently assessing the impact that adoption of ASU 2016-02 will have on our financial position, results of operations or cash flows. Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or its Equivalent), ASU 2015-07 On May 1, 2015, the FASB issued ASU 2015-07, Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or its Equivalent) . The ASU removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient and also removes certain disclosure requirements. The new requirements were effective for us beginning January 1, 2016 and will be applied retrospectively to all periods presented, in our 2016 Form 10-K. This ASU will not materially affect our financial statements and disclosures, but will change certain presentation and disclosure of the fair value of certain plan assets in our pension and other postretirement benefit plan disclosures in our 2016 Form 10-K, for all periods presented. Simplifying the Presentation of Debt Issuance Costs, ASU 2015-03 In April 2015, the FASB issued ASU 2015-03, Simplifying the Presentation of Debt Issuance Costs . Debt issuance costs related to a recognized debt liability will be presented on the balance sheet as a direct deduction from the debt liability, similar to the presentation of debt discounts, rather than as an asset. Amortization of these costs will continue to be reported as interest expense. ASU 2015-03 is effective for annual and interim reporting periods beginning after December 15, 2015. We adopted ASU 2015-03 in the first quarter of 2016 on a retrospective basis. As of March 31, 2016, we have presented the debt issuance costs, previously reported in other assets, as direct deductions from the carrying amount of long-term debt. The implementation of this standard resulted in reductions of other non-current assets and long-term debt of $3.1 million as of December 31, 2015. Adoption of ASU 2015-03 did not have a material impact on our financial position. Revenue from Contracts with Customers, ASU 2014-09 In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers . The standard provides companies with a single model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry-specific revenue guidance. The core principle of the model is to recognize revenue when control of the goods or services transfers to the customer, as opposed to recognizing revenue when the risks and rewards transfer to the customer under the existing revenue guidance. On July 9, 2015, FASB voted to defer the effective date of ASU 2014-09 by one year. The proposed guidance would be effective for annual and interim reporting periods beginning after December 15, 2017 and early adoption is permitted. We are currently evaluating the impact of adoption, if any, that ASU 2014-09 will have on our financial position, results of operations or cash flows.

Accounts Receivable and Allowan

Accounts Receivable and Allowance For Doubtful Accounts:	3 Months Ended
	Mar. 31, 2016
Accounts Receivable, Net [Abstract]
Accounts Receivable and Allowance for Doubtful Accounts	ACCOUNTS RECEIVABLE AND ALLOWANCE FOR DOUBTFUL ACCOUNTS Following is a summary of Receivables - customers, net included in the accompanying Condensed Balance Sheets (in thousands) as of: March 31, 2016 December 31, 2015 Accounts receivable trade $ 15,777 $ 15,268 Unbilled revenues 11,619 12,795 Allowance for doubtful accounts (256 ) (207 ) Receivables - customers, net $ 27,140 $ 27,856

Regulatory Accounting_

Regulatory Accounting:	3 Months Ended
	Mar. 31, 2016
Regulated Operations [Abstract]
Regulatory Assets and Liabilities	REGULATORY ACCOUNTING Our regulated electric operations are subject to regulation by various state and federal agencies. The accounting policies followed are generally subject to the Uniform System of Accounts of the FERC. Our regulatory assets and liabilities were as follows (in thousands) as of: Recovery/Amortization Period (in years) March 31, 2016 December 31, 2015 Regulatory assets: Unamortized loss on reacquired debt (a) 9 $ 2,025 $ 2,096 AFUDC (b) 45 8,719 8,571 Employee benefit plans (c) 12 20,866 20,866 Deferred energy and fuel cost adjustments - current (a) Less than 1 year 21,493 19,875 Flow through accounting (a) 35 12,412 12,104 Decommissioning costs, net of amortization (b) 10 13,317 13,686 Other regulatory assets (a) (d) 2 10,843 8,615 Total regulatory assets $ 89,675 $ 85,813 Regulatory liabilities: Cost of removal for utility plant (a) 53 $ 39,157 $ 38,131 Employee benefit plans (c) 12 12,616 12,616 Other regulatory liabilities 13 906 836 Total regulatory liabilities $ 52,679 $ 51,583 ____________________ (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, respectively. (d) Includes approximately $7.0 million and $5.0 million of vegetation management expenses at March 31, 2016 and December 31, 2015, respectively, for which we are allowed a rate of return.

Related Party Transactions_

Related Party Transactions:	3 Months Ended
	Mar. 31, 2016
Related Party Transactions [Abstract]
Related Party Transactions Disclosure	RELATED-PARTY TRANSACTIONS Receivables and Payables We have accounts receivable and accounts payable balances related to transactions with other BHC subsidiaries. The balances were as follows (in thousands) as of: March 31, 2016 December 31, 2015 Receivables - affiliates $ 8,391 $ 5,747 Accounts payable - affiliates $ 27,148 $ 30,032 Money Pool Notes Receivable and Notes Payable We have entered into a Utility Money Pool Agreement (the “Agreement”) with BHC, Black Hills Service Company and Black Hills Energy. We are the administrator of the Money Pool. Under the Agreement, we may borrow from BHC; however the Agreement restricts us 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 and advances under the Agreement bear interest at the weighted average daily cost of our parent company’s credit facility 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% . At March 31, 2016 , the average cost of borrowing under the Utility Money Pool was 1.62% . We had the following balances with the Utility Money Pool (in thousands) as of: March 31, 2016 December 31, 2015 Money pool notes receivable, net $ 50,630 $ 76,813 Our net interest income (expense) relating to balances with the Utility Money Pool was as follows (in thousands): Three Months Ended March 31, 2016 2015 Net interest income (expense) $ 278 $ 258 Other related party activity was as follows (in thousands): Three Months Ended March 31, 2016 2015 Revenue: Energy sold to Cheyenne Light $ 661 $ 326 Rent from electric properties $ 1,213 $ 1,124 Fuel and purchased power : Purchases of coal from WRDC $ 4,796 $ 4,045 Purchase of excess energy from Cheyenne Light $ 55 $ 476 Purchase of renewable wind energy from Cheyenne Light - Happy Jack $ 664 $ 549 Purchase of renewable wind energy from Cheyenne Light - Silver Sage $ 1,127 $ 936 Gas transportation service agreement: Gas transportation service agreement with Cheyenne Light for firm and interruptible gas transportation $ 136 $ 103 Corporate support: Corporate support services and fees from Parent, Black Hills Service Company and Black Hills Utility Holdings $ 6,721 $ 7,033

Employee Benefit Plans_

Employee Benefit Plans:	3 Months Ended
	Mar. 31, 2016
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Employee Benefit Plans Disclosure	EMPLOYEE BENEFIT PLANS Defined Benefit Pension Plan Beginning in 2016, we changed the method used to estimate the service and interest cost components of the net periodic pension, supplemental non-qualified defined benefit and other postretirement benefit costs. The new method uses the spot yield curve approach to estimate the service and interest costs by applying the specific spot rates along the yield curve used to determine the benefit obligations to relevant projected cash outflows. Previously, those costs were determined using a single weighted-average discount rate. The change does not affect the measurement of the total benefit obligations as the change in service and interest costs offsets the actuarial gains and losses recorded in other comprehensive income. The new method provides a more precise measure of interest and service costs by improving the correlation between the projected benefit cash flows and the discrete spot yield curve rates. We accounted for this change as a change in estimate prospectively beginning in the first quarter of 2016. The discount rates used to measure the 2016 service costs are 4.81% , 4.88% and 4.18% for pension, supplemental non-qualified defined benefit and other postretirement benefit costs, respectively. The discount rates used to measure the 2016 interest costs are 3.90% , 3.82% and 3.17% for pension, supplemental non-qualified defined benefit and other postretirement benefit costs, respectively. The previous method would have used a discount rate for both service and interest costs of 4.63% for pension, 4.50% for supplemental non-qualified defined benefit and 4.03% for other postretirement benefit costs. The decrease in the 2016 service and interest costs is approximately $0.5 million , $0.3 million and $0.1 million for the pension, supplemental non-qualified defined benefit and other postretirement benefit costs, respectively, as compared to the previous method. The components of net periodic benefit cost for the Defined Benefit Pension Plan were as follows (in thousands): Three Months Ended March 31, 2016 2015 Service cost $ 151 $ 199 Interest cost 625 739 Expected return on plan assets (908 ) (984 ) Prior service cost 11 11 Net loss (gain) 499 549 Net periodic benefit cost $ 378 $ 514 Defined Benefit Postretirement Healthcare Plan The components of net periodic benefit cost for the Defined Benefit Postretirement Healthcare Plan were as follows (in thousands): Three Months Ended March 31, 2016 2015 Service cost $ 51 $ 58 Interest cost 47 54 Prior service cost (benefit) (84 ) (84 ) Net periodic benefit cost $ 14 $ 28 Supplemental Non-qualified Defined Benefit Plans The components of net periodic benefit cost for the Supplemental Non-qualified Defined Benefit Plans were as follows (in thousands): Three Months Ended March 31, 2016 2015 Interest cost $ 30 $ 36 Net loss (gain) 21 23 Net periodic benefit cost $ 51 $ 59 Contributions We anticipate we will make contributions to the benefit plans during 2016 and 2017 . Contributions to the Defined Benefit Pension Plan are cash contributions made directly to the Pension Plan Trust accounts. Contributions to the Healthcare and Supplemental Plans are made in the form of benefit payments. Contributions and anticipated contributions are as follows (in thousands): Contributions Three Months Ended March 31, 2016 Remaining Anticipated Contributions for 2016 Anticipated Contributions for 2017 Defined Benefit Pension Plan $ — $ 1,638 $ 1,615 Defined Benefit Postretirement Healthcare Plan $ 155 $ 464 $ 509 Supplemental Non-qualified Defined Benefit Plans $ 54 $ 162 $ 248

Fair Value of Financial Instrum

Fair Value of Financial Instruments:	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	FAIR VALUE OF FINANCIAL INSTRUMENTS Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Accounting guidance on fair value measurements establishes a hierarchy for grouping assets and liabilities, based on significance of inputs. For additional information see Note 1 included in our 2015 Annual Report on Form 10-K filed with the SEC. The estimated fair values of our financial instruments were as follows (in thousands) as of: March 31, 2016 December 31, 2015 Carrying Amount Fair Value Carrying Amount Fair Value Cash and cash equivalents (a) $ 28,999 $ 28,999 $ 7,559 $ 7,559 Long-term debt, including current maturities (b) $ 339,651 $ 429,059 $ 342,756 $ 404,864 _________________ (a) Carrying value approximates fair value due to either short-term length of maturity or variable interest rates that approximate prevailing market rates and therefore is classified in Level 1 in the fair value hierarchy. (b) Long-term debt is valued using the market approach based on observable inputs of quoted market prices and yields available for debt instruments either directly or indirectly for similar maturities and debt ratings in active markets and therefore is classified in Level 2 in the fair value hierarchy. The carrying amount of our variable rate debt approximates fair value due to the variable interest rates with short reset periods.

Supplemental Disclosure of Cash

Supplemental Disclosure of Cash Flow Information:	3 Months Ended
	Mar. 31, 2016
Supplemental Cash Flow Information [Abstract]
Cash Flow, Supplemental Disclosures	SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION Three months ended March 31, 2016 2015 (in thousands) Non-cash investing and financing activities - Property, plant and equipment acquired with accrued liabilities $ 5,087 $ 2,042 Non-cash (decrease) to money pool notes receivable, net $ (12,500 ) $ — Non-cash dividend to Parent $ 12,500 $ — Cash (paid) refunded during the period for - Interest (net of amounts capitalized) $ (2,989 ) $ (2,718 ) Income taxes, net $ — $ —

Commitment and Contingencies_

Commitment and Contingencies:	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure	COMMITMENTS AND CONTINGENCIES There have been no significant changes to commitments and contingencies from those previously disclosed in Note 11 of our Notes to the Financial Statements in our 2015 Annual Report on Form 10-K.

Accounts Receivable and Allow15

Accounts Receivable and Allowance For Doubtful Accounts: Accounts Receivable and Allowance For Doubtful Accounts (Tables)	3 Months Ended
	Mar. 31, 2016
Accounts Receivable, Net [Abstract]
Schedule of Accounts Receivable	Following is a summary of Receivables - customers, net included in the accompanying Condensed Balance Sheets (in thousands) as of: March 31, 2016 December 31, 2015 Accounts receivable trade $ 15,777 $ 15,268 Unbilled revenues 11,619 12,795 Allowance for doubtful accounts (256 ) (207 ) Receivables - customers, net $ 27,140 $ 27,856

Regulatory Accounting_ Regulato

Regulatory Accounting: Regulatory Accounting (Tables)	3 Months Ended
	Mar. 31, 2016
Regulated Operations [Abstract]
Schedule of Regulatory Assets	Our regulatory assets and liabilities were as follows (in thousands) as of: Recovery/Amortization Period (in years) March 31, 2016 December 31, 2015 Regulatory assets: Unamortized loss on reacquired debt (a) 9 $ 2,025 $ 2,096 AFUDC (b) 45 8,719 8,571 Employee benefit plans (c) 12 20,866 20,866 Deferred energy and fuel cost adjustments - current (a) Less than 1 year 21,493 19,875 Flow through accounting (a) 35 12,412 12,104 Decommissioning costs, net of amortization (b) 10 13,317 13,686 Other regulatory assets (a) (d) 2 10,843 8,615 Total regulatory assets $ 89,675 $ 85,813
Schedule of Regulatory Liabilities	Regulatory liabilities: Cost of removal for utility plant (a) 53 $ 39,157 $ 38,131 Employee benefit plans (c) 12 12,616 12,616 Other regulatory liabilities 13 906 836 Total regulatory liabilities $ 52,679 $ 51,583 ____________________ (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, respectively. (d) Includes approximately $7.0 million and $5.0 million of vegetation management expenses at March 31, 2016 and December 31, 2015, respectively, for which we are allowed a rate of return.

Related Party Transactions_ Rel

Related Party Transactions: Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2016
Related Party Transactions [Abstract]
Schedule of Related Party Accounts Receivable and Payable	The balances were as follows (in thousands) as of: March 31, 2016 December 31, 2015 Receivables - affiliates $ 8,391 $ 5,747 Accounts payable - affiliates $ 27,148 $ 30,032
Schedule of Related Party Notes	We had the following balances with the Utility Money Pool (in thousands) as of: March 31, 2016 December 31, 2015 Money pool notes receivable, net $ 50,630 $ 76,813
Schedule of Related Party Interest Income Expense	Our net interest income (expense) relating to balances with the Utility Money Pool was as follows (in thousands): Three Months Ended March 31, 2016 2015 Net interest income (expense) $ 278 $ 258
Schedule of Revenues and Purchases from Related Parties	Other related party activity was as follows (in thousands): Three Months Ended March 31, 2016 2015 Revenue: Energy sold to Cheyenne Light $ 661 $ 326 Rent from electric properties $ 1,213 $ 1,124 Fuel and purchased power : Purchases of coal from WRDC $ 4,796 $ 4,045 Purchase of excess energy from Cheyenne Light $ 55 $ 476 Purchase of renewable wind energy from Cheyenne Light - Happy Jack $ 664 $ 549 Purchase of renewable wind energy from Cheyenne Light - Silver Sage $ 1,127 $ 936 Gas transportation service agreement: Gas transportation service agreement with Cheyenne Light for firm and interruptible gas transportation $ 136 $ 103 Corporate support: Corporate support services and fees from Parent, Black Hills Service Company and Black Hills Utility Holdings $ 6,721 $ 7,033

Employee Benefit Plans_ Employe

Employee Benefit Plans: Employee Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2016
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Schedule of Net Benefit Costs	The components of net periodic benefit cost for the Defined Benefit Pension Plan were as follows (in thousands): Three Months Ended March 31, 2016 2015 Service cost $ 151 $ 199 Interest cost 625 739 Expected return on plan assets (908 ) (984 ) Prior service cost 11 11 Net loss (gain) 499 549 Net periodic benefit cost $ 378 $ 514 Defined Benefit Postretirement Healthcare Plan The components of net periodic benefit cost for the Defined Benefit Postretirement Healthcare Plan were as follows (in thousands): Three Months Ended March 31, 2016 2015 Service cost $ 51 $ 58 Interest cost 47 54 Prior service cost (benefit) (84 ) (84 ) Net periodic benefit cost $ 14 $ 28 Supplemental Non-qualified Defined Benefit Plans The components of net periodic benefit cost for the Supplemental Non-qualified Defined Benefit Plans were as follows (in thousands): Three Months Ended March 31, 2016 2015 Interest cost $ 30 $ 36 Net loss (gain) 21 23 Net periodic benefit cost $ 51 $ 59
Schedule of Defined Benefit Plans Contributions	Contributions and anticipated contributions are as follows (in thousands): Contributions Three Months Ended March 31, 2016 Remaining Anticipated Contributions for 2016 Anticipated Contributions for 2017 Defined Benefit Pension Plan $ — $ 1,638 $ 1,615 Defined Benefit Postretirement Healthcare Plan $ 155 $ 464 $ 509 Supplemental Non-qualified Defined Benefit Plans $ 54 $ 162 $ 248

Fair Value of Financial Instr19

Fair Value of Financial Instruments: Fair Value of Financial Instruments(Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Financial Instruments	The estimated fair values of our financial instruments were as follows (in thousands) as of: March 31, 2016 December 31, 2015 Carrying Amount Fair Value Carrying Amount Fair Value Cash and cash equivalents (a) $ 28,999 $ 28,999 $ 7,559 $ 7,559 Long-term debt, including current maturities (b) $ 339,651 $ 429,059 $ 342,756 $ 404,864 _________________ (a) Carrying value approximates fair value due to either short-term length of maturity or variable interest rates that approximate prevailing market rates and therefore is classified in Level 1 in the fair value hierarchy. (b) Long-term debt is valued using the market approach based on observable inputs of quoted market prices and yields available for debt instruments either directly or indirectly for similar maturities and debt ratings in active markets and therefore is classified in Level 2 in the fair value hierarchy. The carrying amount of our variable rate debt approximates fair value due to the variable interest rates with short reset periods.

Supplemental Disclosure of Ca20

Supplemental Disclosure of Cash Flow Information: Supplemental Disclosures of Cash Flow Information (Tables)	3 Months Ended
	Mar. 31, 2016
Supplemental Cash Flow Information [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	Three months ended March 31, 2016 2015 (in thousands) Non-cash investing and financing activities - Property, plant and equipment acquired with accrued liabilities $ 5,087 $ 2,042 Non-cash (decrease) to money pool notes receivable, net $ (12,500 ) $ — Non-cash dividend to Parent $ 12,500 $ — Cash (paid) refunded during the period for - Interest (net of amounts capitalized) $ (2,989 ) $ (2,718 ) Income taxes, net $ — $ —

Management's Statement_ Simplif

Management's Statement: Simplifying the Presentation of Debt Issuance Costs (Details) $ in Millions	Dec. 31, 2015USD ($)
Other Noncurrent Liabilities [Member]
New Accounting Pronouncement - Deferred Financing Costs	$ 3.1

Accounts Receivable and Allow22

Accounts Receivable and Allowance For Doubtful Accounts: Accounts Receivable and Allowance For Doubtful Accounts (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accounts Receivable [Line Items]
Allowance for doubtful accounts	$ (256)	$ (207)
Receivables - customers, net	27,140	27,856
Billed Revenues [Member]
Accounts Receivable [Line Items]
Accounts receivable, trade	15,777	15,268
Unbilled Revenues [Member]
Accounts Receivable [Line Items]
Accounts receivable, trade	$ 11,619	$ 12,795

Regulatory Accounting_ Regula23

Regulatory Accounting: Regulatory Accounting (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Dec. 31, 2015
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets		$ 89,675	$ 85,813
Regulatory Liabilities		$ 52,679	51,583
Cost of removal for utility plant [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities Amortization Period, Unclassified		53 years
Regulatory Liabilities	[1]	$ 39,157	38,131
Employee benefit plans [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities Amortization Period, Unclassified		12 years
Regulatory Liabilities	[2]	$ 12,616	12,616
Other regulatory liabilities [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities Amortization Period, Unclassified		13 years
Regulatory Liabilities		$ 906	836
Unamortized Loss on reacquired debt [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets Amortization Period, Unclassified		9 years
Regulatory Assets	[1]	$ 2,025	2,096
Allowance For Funds Used During Construction [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets Amortization Period, Unclassified		45 years
Regulatory Assets	[3]	$ 8,719	8,571
Employee benefit plans [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets Amortization Period, Unclassified		12 years
Regulatory Assets	[2]	$ 20,866	20,866
Deferred energy and fuel cost adjustments - current [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets	[1]	$ 21,493	19,875
Flow through accounting [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets Amortization Period, Unclassified		35 years
Regulatory Assets	[1]	$ 12,412	12,104
Decommissioning costs, net of amortization [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets Amortization Period, Unclassified		10 years
Regulatory Assets		$ 13,317	13,686
Other regulatory assets [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets Amortization Period, Unclassified		2 years
Regulatory Assets	[1],[4]	$ 10,843	8,615
Vegetation Management [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets		$ 7,000	$ 5,000
[1]	Recovery of costs, but we are not allowed a rate of return.
[2]	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, respectively.
[3]	In addition to recovery of costs, we are allowed a rate of return.
[4]	Includes approximately $7.0 million and $5.0 million of vegetation management expenses at March 31, 2016 and December 31, 2015, respectively, for which we are allowed a rate of return.

Related Party Transactions_ R24

Related Party Transactions: Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Related Party Transaction [Line Items]
Receivables - affiliates	$ 8,391		$ 5,747
Accounts payable - affiliates	$ 27,148		30,032
Related Party Transaction, Utility Money Pool Interest Rate	1.62%
Money pool notes receivable, net	$ 50,630		$ 76,813
Parent [Member]
Related Party Transaction [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	1.00%
Utility Money Pool [Member]
Related Party Transaction [Line Items]
Net interest income (expense)	$ 278	$ 258
Subsidiary of Common Parent [Member] | Allocated Costs From Related Parties [Member]
Related Party Transaction [Line Items]
Costs and expenses, related parties	6,721	7,033
Subsidiary of Common Parent [Member] | Purchase Of Natural Gas, Cheyenne Light [Member]
Related Party Transaction [Line Items]
Costs and expenses, related parties	136	103
Subsidiary of Common Parent [Member] | Coal, Purchased [Member]
Related Party Transaction [Line Items]
Costs and expenses, related parties	4,796	4,045
Subsidiary of Common Parent [Member] | Purchase of Excess Energy, Cheyenne Light [Member]
Related Party Transaction [Line Items]
Costs and expenses, related parties	55	476
Subsidiary of Common Parent [Member] | Happy Jack Wind Purchase Power Agreeement [Member]
Related Party Transaction [Line Items]
Costs and expenses, related parties	664	549
Subsidiary of Common Parent [Member] | Silver Sage Wind Power Purchase Agreement [Member]
Related Party Transaction [Line Items]
Costs and expenses, related parties	1,127	936
Subsidiary of Common Parent [Member] | Energy sold to Cheyenne Light [Member]
Related Party Transaction [Line Items]
Revenue from related parties	661	326
Subsidiary of Common Parent [Member] | Lease Agreements [Member]
Related Party Transaction [Line Items]
Revenue from related parties	$ 1,213	$ 1,124

Employee Benefit Plans_ Emplo25

Employee Benefit Plans: Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Decrease In Interest and Service Costs Resulting From New Spot Method Approach	$ 500
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	151	$ 199
Interest cost	625	739
Expected return on plan assets	(908)	(984)
Prior service cost (benefit)	11	11
Net loss (gain)	499	549
Net periodic benefit cost	378	514
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions made by Employer	0
Remaining Anticipated Contributions for Current Year	1,638
Anticipated Contributions for Next Year	1,615
Defined Benefit Postretirement Healthcare Plan
Defined Benefit Plan Disclosure [Line Items]
Decrease In Interest and Service Costs Resulting From New Spot Method Approach	100
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	51	58
Interest cost	47	54
Prior service cost (benefit)	(84)	(84)
Net periodic benefit cost	14	28
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions made by Employer	155
Remaining Anticipated Contributions for Current Year	464
Anticipated Contributions for Next Year	509
Supplemental Non-qualified Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Decrease In Interest and Service Costs Resulting From New Spot Method Approach	300
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Interest cost	30	36
Net loss (gain)	21	23
Net periodic benefit cost	51	$ 59
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions made by Employer	54
Remaining Anticipated Contributions for Current Year	162
Anticipated Contributions for Next Year	$ 248
Scenario, Previously Reported [Member] | Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.63%
Scenario, Previously Reported [Member] | Defined Benefit Postretirement Healthcare Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.03%
Scenario, Previously Reported [Member] | Supplemental Non-qualified Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.50%
Service Cost [Member] | Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.81%
Service Cost [Member] | Defined Benefit Postretirement Healthcare Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.18%
Service Cost [Member] | Supplemental Non-qualified Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.88%
Interest Cost [Member] | Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.90%
Interest Cost [Member] | Defined Benefit Postretirement Healthcare Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.17%
Interest Cost [Member] | Supplemental Non-qualified Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	3.82%

Fair Value of Financial Instr26

Fair Value of Financial Instruments: Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, carrying amount		$ 28,999	$ 7,559	$ 55,084	$ 6,620
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, carrying amount	[1]	28,999	7,559
Long-term debt, including current maturities, carrying amount	[2]	339,651	342,756
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	[1]	28,999	7,559
Long-term debt, including current maturities, fair value	[2]	$ 429,059	$ 404,864
[1]	Carrying value approximates fair value due to either short-term length of maturity or variable interest rates that approximate prevailing market rates and therefore is classified in Level 1 in the fair value hierarchy.
[2]	Long-term debt is valued using the market approach based on observable inputs of quoted market prices and yields available for debt instruments either directly or indirectly for similar maturities and debt ratings in active markets and therefore is classified in Level 2 in the fair value hierarchy. The carrying amount of our variable rate debt approximates fair value due to the variable interest rates with short reset periods.

Supplemental Disclosure of Ca27

Supplemental Disclosure of Cash Flow Information: Supplemental Disclosures of Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Noncash Investing and Financing Items [Abstract]
Property, plant and equipment acquired with accrued liabilities	$ 5,087	$ 2,042
Interest and Income Taxes Paid Net [Abstract]
Interest paid, (net of amounts capitalized)	(2,989)	(2,718)
Income taxes, net	0	0
Subsidiary of Common Parent [Member]
Noncash Investing and Financing Items [Abstract]
Non-cash (decrease) to money pool notes receivable, net	(12,500)	0
Parent [Member]
Noncash Investing and Financing Items [Abstract]
Non-cash dividend to Parent	$ 12,500	$ 0