Black Hills (BKH) 10-Q/A 7 Aug 15 2015 Q1 Quarterly report (amended) Financial data

Document and Entity Information

Document and Entity Information Document - shares	3 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Document Information [Line Items]
Entity Registrant Name	BLACK HILLS CORP /SD/
Entity Central Index Key	1,130,464
Document Type	10-Q/A
Document Period End Date	Mar. 31, 2015
Amendment Flag	true
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		44,821,847
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Amendment Description	test

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (Loss) (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Revenue	$ 441,987	$ 460,169
Utilities -
Fuel, purchased power and cost of natural gas sold	205,327	230,468
Operations and maintenance	71,084	71,227
Non-regulated energy operations and maintenance	22,050	22,332
Depreciation, depletion and amortization	39,002	35,249
Taxes - property, production and severance	11,936	10,336
Impairment of long-lived assets	22,036	0
Other operating expenses	52	125
Total operating expenses	371,487	369,737
Operating income	70,500	90,432
Interest charges -
Interest expense incurred (including amortization of debt issuance costs, premiums and discounts and realized settlements on interest rate swaps)	(19,910)	(17,860)
Allowance for funds used during construction - borrowed	158	270
Capitalized interest	276	257
Interest income	448	390
Allowance for funds used during construction - equity	56	238
Other income (expense), net	331	592
Total other income (expense), net	(18,641)	(16,113)
Income (loss) before earnings (loss) of unconsolidated subsidiaries and income taxes	51,859	74,319
Equity in earnings (loss) of unconsolidated subsidiaries	(297)	(1)
Income tax benefit (expense)	(17,712)	(25,673)
Net income (loss) available for common stock	$ 33,850	$ 48,645
Earnings (loss) per share of common stock:
Earnings (loss) per share, Basic	$ 0.76	$ 1.10
Earnings (loss) per share, Diluted	$ 0.76	$ 1.09
Weighted average common shares outstanding:
Basic	44,541	44,330
Diluted	44,660	44,554
Dividends declared per share of common stock	$ 0.405	$ 0.390

Condensed Consolidated Stateme3

Condensed Consolidated Statement of Comprehensive Income (unaudited) Statement - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss) available for common stock	$ 33,850	$ 48,645
Operating income (loss)	70,500	90,432
Other comprehensive income (loss), net of tax:
Fair value adjustments on derivatives designated as cash flow hedges (net of tax (expense) benefit of $(1,042) and $1,307 for the three months ended 2015 and 2014, respectively)	1,836	(2,257)
Reclassification adjustments for cash flow hedges settled and included in net income (loss) (net of tax (expense) benefit of $1,254 and $(425) for the three months ended 2015 and 2014, respectively)	(1,241)	780
Benefit plan liability adjustments - net gain (loss) (net of tax (expense) benefit of $15 and $2 for the three months ended 2015 and 2014, respectively)	(27)	(2)
Benefit plan liability adjustments - prior service cost (net of tax (expense) benefit of $(90) for the three months ended 2014	0	164
Reclassification adjustments of benefit plan liability - prior service cost (net of tax (expense) benefit of $19 and $4 for the three months ended 2015 and 2014, respectively)	(36)	(9)
Reclassification adjustments of benefit plan liability - net gain (loss) (net of tax (expense) benefit of $(247) and $(85) for the three months ended 2015 and 2014, respectively)	458	157
Other comprehensive income (loss), net of tax	990	(1,167)
Comprehensive income (loss) available for common stock	34,840	47,478
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures
Fair value adjustment on derivatives designated as cash flow hedges, (tax) benefit	(1,043)	1,307
Reclassification adjustments of cash flow hedges settled and included in net income, (tax) benefit	1,254	(425)
Benefit plan liability adjustments net gain, (tax) benefit	15	2
Benefit plan liability adjustments prior service cost, (tax) benefit	0	(90)
Reclassification adjustment of benefit plan prior service cost included in net income, (tax) benefit	19	4
Reclassification adjustment of benefit plan liabilities actuarial gain (loss), (tax) benefit	$ (247)	$ (85)

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (unaudited) Statement - USD ($) $ in Thousands	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Current assets:
Cash and cash equivalents	$ 63,385	$ 21,218	$ 17,641
Restricted cash and equivalents	2,191	2,056	2
Accounts receivable, net	178,421	189,992	203,625
Materials, supplies and fuel	66,626	91,191	66,187
Derivative assets, current	0	0	1,846
Income tax receivable, net	159	2,053	1,826
Deferred income tax assets, net, current	23,913	48,288	25,780
Regulatory assets, current	56,542	74,396	62,946
Other current assets	47,448	24,842	24,563
Total current assets	438,685	454,036	404,416
Investments	17,210	17,294	16,916
Property, plant and equipment	4,652,058	4,563,400	4,318,194
Less: accumulated depreciation and depletion	(1,407,214)	(1,357,929)	(1,334,806)
Total property, plant and equipment, net	3,244,844	3,205,471	2,983,388
Other assets:
Goodwill	353,396	353,396	353,396
Intangible assets, net	3,121	3,176	3,342
Regulatory assets, non-current	178,935	183,443	138,173
Other assets, non-current	28,280	29,086	28,925
Total other assets, non-current	563,732	569,101	523,836
TOTAL ASSETS	4,264,471	4,245,902	3,928,556
Current liabilities:
Accounts payable	88,770	124,139	149,681
Accrued liabilities	166,781	170,115	145,973
Derivative liabilities, current	3,342	3,340	3,498
Regulatory liabilities, current	17,621	3,687	583
Notes payable	102,600	75,000	100,000
Current maturities of long-term debt	0	275,000	0
Total current liabilities	379,114	651,281	399,735
Long-term debt, net of current maturities	1,542,658	1,267,589	1,396,949
Deferred credits and other liabilities:
Deferred income tax liability, non-current	503,117	511,952	454,169
Derivative liabilities, non-current	2,143	2,680	4,805
Regulatory liabilities, non-current	148,918	145,144	116,793
Benefit plan liabilities	162,334	158,966	113,324
Total deferred credits and other liabilities	154,604	154,406	129,083
Total deferred credits and other liabilities	$ 971,116	$ 973,148	$ 818,174
Commitments and contingencies (See Notes 7, 8, 13, 14)
Stockholders’ equity:
Common stock $1 par value; 100,000,000 shares authorized; issued 44,856,790; 44,714,072; and 44,666,953 shares, respectively	$ 44,857	$ 44,714	$ 44,667
Additional Paid in Capital	749,517	748,840	742,016
Retained earnings	592,951	577,249	547,242
Treasury stock, at cost – 33,755; 42,226; and 37,038 shares, respectively	(1,688)	(1,875)	(1,638)
Accumulated other comprehensive income (loss)	(14,054)	(15,044)	(18,589)
Total stockholders’ equity	1,371,583	1,353,884	1,313,698
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 4,264,471	$ 4,245,902	$ 3,928,556

Condensed Consolidated Balance5

Condensed Consolidated Balance Sheets (unaudited) Condensed Consolidated Balance Sheets (Parentheticals) - $ / shares	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Statement of Financial Position [Abstract]
Common Stock, Par Per Share	$ 1	$ 1	$ 1
Common Stock, Shares Issued	44,856,790	44,714,072	44,666,953
Treasury Stock, Shares	33,755	42,226	37,038
Common Stock, Shares Authorized	100,000,000	100,000,000	100,000,000

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Operating activities:
Net income (loss) available for common stock	$ 33,850	$ 48,645
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	39,002	35,249
Deferred financing cost amortization	519	568
Impairment of long-lived assets	22,036	0
Stock compensation	2,083	3,716
Deferred income taxes	14,640	26,260
Employee benefit plans	5,283	3,703
Other adjustments, net	6,748	5,190
Changes in certain operating assets and liabilities:
Materials, supplies and fuel	25,689	22,291
Accounts receivable, unbilled revenues and other operating assets	47,947	(78,576)
Accounts payable and other operating liabilities	(44,652)	29,074
Other operating activities, net	(1,658)	1,978
Net Cash Provided by (Used in) Operating Activities	151,487	98,098
Investing activities:
Property, plant and equipment additions	(117,523)	(83,609)
Other investing activities	(348)	(3,220)
Net Cash Provided by (Used in) Investing Activities	(117,871)	(86,829)
Financing activities:
Dividends paid on common stock	(18,148)	(17,399)
Common stock issued	999	881
Short-term borrowings - issuances	77,700	86,800
Short-term borrowings - repayments	(50,100)	(69,300)
Other financing activities	(1,900)	(2,451)
Net Cash Provided by (Used in) Financing Activities	8,551	(1,469)
Net change in cash and cash equivalents	42,167	9,800
Cash and Cash Equivalents
Cash and cash equivalents, beginning of period	21,218	7,841
Cash and cash equivalents, end of period	$ 63,385	$ 17,641

Management Statement_ Managemen

Management Statement: Management Statement (Notes)	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]	MANAGEMENT’S STATEMENT The unaudited Condensed Consolidated Financial Statements included herein have been prepared by Black Hills Corporation (together with our subsidiaries the “Company,” “us,” “we,” 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 Consolidated Financial Statements should be read in conjunction with the consolidated financial statements and the notes thereto included in our 2014 Annual Report on Form 10-K/A filed with the SEC. We conduct our operations through the following reportable segments: Electric Utilities, Gas Utilities, Power Generation, Coal Mining and Oil and Gas. Our reportable segments are based on our method of internal reporting, which generally segregates the strategic business groups due to differences in products, services and regulation. All of our operations and assets are located within the United States. Accounting methods historically employed require certain estimates as of interim dates. The information furnished in the accompanying Condensed Consolidated Financial Statements reflects all adjustments, including accruals, which are, in the opinion of management, necessary for a fair presentation of the March 31, 2015 , December 31, 2014 , and March 31, 2014 financial information and are of a normal recurring nature. Certain industries in which we operate are highly seasonal, and revenue from, and certain expenses for, such operations may fluctuate significantly among quarterly periods. Demand for electricity and natural gas is sensitive to seasonal cooling, heating and industrial load requirements, as well as changes in market price. In particular, the normal peak usage season for electric utilities is June through August while the normal peak usage season for gas utilities is November through March. Significant earnings variances can be expected between the Gas Utilities segment’s peak and off-peak seasons. Due to this seasonal nature, our results of operations for the three months ended March 31, 2015 and March 31, 2014 , and our financial condition as of March 31, 2015 , December 31, 2014 , and March 31, 2014 , are not necessarily indicative of the results of operations and financial condition to be expected as of or for any other period. All earnings per share amounts discussed refer to diluted earnings per share unless otherwise noted. Recently Issued and Adopted Accounting Standards We have implemented all new accounting pronouncements that are in effect and may impact our financial statements. We are currently assessing the impact any other new accounting pronouncements that have been issued may have on our financial position, results of operations, or cash flows. 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. Early adoption is permitted. We are currently evaluating the impact of adoption that ASU 2015-03 will have on our financial position, results of operations, or cash flows. 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 April 1, 2015, FASB voted to propose 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 assessing the impact, if any, that ASU 2014-09 will have on our financial position, results of operations or cash flows.

Management Statement (continued

Management Statement (continued) Revision of Prior Period Financial Statements (Notes)	3 Months Ended
	Mar. 31, 2015
Accounting Changes and Error Corrections [Abstract]
Accounting Changes and Error Corrections [Text Block]	Correction of Immaterial Errors In preparing our condensed consolidated financial statements for the quarter ended June 30, 2015, we identified immaterial errors that impacted our previously issued consolidated financial statements. The prior period errors originated in the year ended December 31, 2008 and related to our oil and gas full cost ceiling impairment calculation to determine whether the net book value of the our oil and gas properties exceeded the ceiling. Specifically, the errors related to evaluating and correctly accounting for the treatment of tax related amounts associated with the calculation. The errors identified caused an understatement of 2008, 2009, 2012 and Q1 2015 noncash ceiling test impairment calculations, which resulted in an overstatement of depletion expense from 2009 through March 31, 2015, and an understatement of the 2012 gain on sale of oil and gas properties. In accordance with Staff Accounting Bulletin (SAB) No. 99, Materiality , and SAB No. 108, Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements , we evaluated these errors, including both qualitative and quantitative considerations, and concluded that the errors did not, individually or in the aggregate, result in a material misstatement of our previously issued condensed consolidated financial statements. The following tables present the revisions to particular line items resulting from the corrections of these errors in this Quarterly Report on Form 10-Q/A. The impact of the errors relate entirely to our Oil and Gas segment. CONDENSED CONSOLIDATED STATEMENTS OF INCOME For the Three Months Ended March 31, 2015 As Reported Adjustments As Revised (in thousands) Depreciation, depletion and amortization $ 39,586 $ (584 ) $ 39,002 Impairment of long-lived assets $ — $ 22,036 $ 22,036 Total operating expenses $ 350,035 $ 21,452 $ 371,487 Operating income (loss) $ 91,952 $ (21,452 ) $ 70,500 Income (loss) before earnings (loss) of unconsolidated subsidiaries and income taxes $ 73,311 $ (21,452 ) $ 51,859 Income tax benefit (expense) $ (25,120 ) $ 7,408 $ (17,712 ) Net income (loss) available for common stock $ 47,894 $ (14,044 ) $ 33,850 Earnings (loss) per share of common stock: Earnings (loss) per share, Basic $ 1.08 $ (0.32 ) $ 0.76 Earnings (loss) per share, Diluted $ 1.07 $ (0.31 ) $ 0.76 For the Three Months Ended March 31, 2014 As Reported Adjustments As Revised (in thousands) Depreciation, depletion and amortization $ 36,083 $ (834 ) $ 35,249 Total operating expenses $ 370,571 $ (834 ) $ 369,737 Operating income (loss) $ 89,598 $ 834 $ 90,432 Income (loss) before earnings (loss) of unconsolidated subsidiaries and income taxes $ 73,485 $ 834 $ 74,319 Income tax benefit (expense) $ (25,366 ) $ (307 ) $ (25,673 ) Net income (loss) available for common stock $ 48,118 $ 527 $ 48,645 Earnings (loss) per share of common stock: Earnings (loss) per share, Basic - $ 1.09 $ 0.01 $ 1.10 Earnings (loss) per share, Diluted - $ 1.08 $ 0.01 $ 1.09 CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) For the Three Months Ended March 31, 2015 2014 (in thousands) As Reported Adjustments As Revised As Reported Adjustments As Revised Net income (loss) available for common stock $ 47,894 $ (14,044 ) $ 33,850 $ 48,118 $ 527 $ 48,645 Comprehensive income (loss) $ 48,884 $ (14,044 ) $ 34,840 $ 46,951 $ 527 $ 47,478 CONDENSED CONSOLIDATED BALANCE SHEET As of March 31, 2015 As of March 31, 2014 As Reported Adjustments As Revised As Reported Adjustments As Revised (in thousands) Accumulated depreciation and depletion $ (1,351,857 ) $ (55,357 ) $ (1,407,214 ) $ (1,298,398 ) $ (36,408 ) $ (1,334,806 ) Total property, plant and equipment, net $ 3,300,201 $ (55,357 ) $ 3,244,844 $ 3,019,796 $ (36,408 ) $ 2,983,388 TOTAL ASSETS $ 4,319,828 $ (55,357 ) $ 4,264,471 $ 3,964,964 $ (36,408 ) $ 3,928,556 Deferred income tax liability, non-current $ 522,290 $ (19,173 ) $ 503,117 $ 466,856 $ (12,687 ) $ 454,169 Total deferred credits and other liabilities $ 990,289 $ (19,173 ) $ 971,116 $ 830,861 $ (12,687 ) $ 818,174 Retained earnings $ 629,135 $ (36,184 ) $ 592,951 $ 570,963 $ (23,721 ) $ 547,242 Total stockholders' equity $ 1,407,767 $ (36,184 ) $ 1,371,583 $ 1,337,419 $ (23,721 ) $ 1,313,698 TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY $ 4,319,828 $ (55,357 ) $ 4,264,471 $ 3,964,964 $ (36,408 ) $ 3,928,556 CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS Three Months Ended March 31, 2015 Three Months Ended March 31, 2014 As Reported Adjustments As Revised As Reported Adjustments As Revised (in thousands) Net income (loss) available for common stock $ 47,894 $ (14,044 ) $ 33,850 $ 48,118 $ 527 $ 48,645 Adjustments to reconcile net income (loss) to net cash provided by operating activities: Depreciation, depletion and amortization $ 39,586 $ (584 ) $ 39,002 $ 36,083 $ (834 ) $ 35,249 Impairment of long-lived assets $ — $ 22,036 $ 22,036 $ — $ — $ — Deferred income taxes $ 22,048 $ (7,408 ) $ 14,640 $ 25,953 $ 307 $ 26,260 Net cash provided by (used in) operating activities $ 151,487 $ — $ 151,487 $ 98,098 $ — $ 98,098 The Notes to the Condensed Consolidated Financial Statements have been revised to reflect the correction of these errors for all periods presented.

Business Segment Information_

Business Segment Information:	3 Months Ended
	Mar. 31, 2015
Segment Reporting Information, Additional Information [Abstract]
Business Segment Information	BUSINESS SEGMENT INFORMATION Segment information and Corporate activities included in the accompanying Condensed Consolidated Statements of Income (Loss) were as follows (in thousands): Three Months Ended March 31, 2015 External Operating Revenue Inter-company Operating Revenue Net Income (Loss) Utilities: Electric $ 182,974 $ 3,424 $ 18,929 Gas 237,651 — 22,212 Non-regulated Energy: Power Generation 1,953 20,721 8,145 Coal Mining 8,142 7,792 3,010 Oil and Gas (a) 11,267 — (19,115 ) Corporate activities — — 669 Inter-company eliminations — (31,937 ) — Total $ 441,987 $ — $ 33,850 ________________ (a) Net income (loss) includes ceiling test impairment (see Note 15 ) Three Months Ended March 31, 2014 External Operating Revenue Inter-company Operating Revenue Net Income (Loss) Utilities: Electric $ 178,095 $ 4,007 $ 14,575 Gas 259,337 — 24,698 Non-regulated Energy: Power Generation 1,269 21,079 8,073 Coal Mining 6,618 8,880 2,464 Oil and Gas 14,850 — (1,495 ) Corporate activities — — 330 Inter-company eliminations — (33,966 ) — Total $ 460,169 $ — $ 48,645 Segment information and Corporate balances included in the accompanying Condensed Consolidated Balance Sheets were as follows (in thousands): Total Assets (net of inter-company eliminations) as of: March 31, 2015 December 31, 2014 March 31, 2014 Utilities: Electric (a) $ 2,817,423 $ 2,748,680 $ 2,572,616 Gas 839,802 906,922 842,660 Non-regulated Energy: Power Generation (a) 75,945 76,945 90,643 Coal Mining 77,399 74,407 74,523 Oil and Gas (b) 348,300 332,343 258,675 Corporate activities 105,602 106,605 89,439 Total assets $ 4,264,471 $ 4,245,902 $ 3,928,556 __________ (a) The PPA under which Black Hills Colorado IPP provides generation to support Colorado Electric customers from the Pueblo Airport Generation Station is accounted for as a capital lease. As such, assets owned by our Power Generation segment are recorded at Colorado Electric under accounting for a capital lease. (b) As a result of continued low commodity prices during 2015, we recorded a non-cash impairment of oil and gas assets included in our Oil and Gas segment of $22 million for the three months ended March 31, 2015. See Note 1 to the Condensed Consolidated Financial statements in this Quarterly Report on Form 10-Q/A.

Accounts Receivable_

Accounts Receivable:	3 Months Ended
	Mar. 31, 2015
Receivables [Abstract]
Accounts Receivable	ACCOUNTS RECEIVABLE Following is a summary of Accounts receivable, net included in the accompanying Condensed Consolidated Balance Sheets (in thousands) as of: Accounts Unbilled Less Allowance for Accounts March 31, 2015 Receivable, Trade Revenue Doubtful Accounts Receivable, net Electric Utilities $ 53,862 $ 24,540 $ (834 ) $ 77,568 Gas Utilities 63,252 28,785 (1,588 ) 90,449 Power Generation 1,152 — — 1,152 Coal Mining 3,638 — — 3,638 Oil and Gas 4,646 — (13 ) 4,633 Corporate 981 — — 981 Total $ 127,531 $ 53,325 $ (2,435 ) $ 178,421 Accounts Unbilled Less Allowance for Accounts December 31, 2014 Receivable, Trade Revenue Doubtful Accounts Receivable, net Electric Utilities $ 59,714 $ 26,474 $ (722 ) $ 85,466 Gas Utilities 47,394 45,546 (781 ) 92,159 Power Generation 1,369 — — 1,369 Coal Mining 3,151 — — 3,151 Oil and Gas 5,305 — (13 ) 5,292 Corporate 2,555 — — 2,555 Total $ 119,488 $ 72,020 $ (1,516 ) $ 189,992 Accounts Unbilled Less Allowance for Accounts March 31, 2014 Receivable, Trade Revenue Doubtful Accounts Receivable, net Electric Utilities $ 53,733 $ 20,063 $ (690 ) $ 73,106 Gas Utilities 77,982 35,791 (814 ) 112,959 Power Generation 1,340 — — 1,340 Coal Mining 2,616 — — 2,616 Oil and Gas 10,920 — (13 ) 10,907 Corporate 2,697 — — 2,697 Total $ 149,288 $ 55,854 $ (1,517 ) $ 203,625

Regulatory Accounting_

Regulatory Accounting:	3 Months Ended
	Mar. 31, 2015
Regulatory Assets and Liabilities Disclosure [Abstract]
Regulatory Accounting	REGULATORY ACCOUNTING We had the following regulatory assets and liabilities (in thousands): Maximum As of As of As of Amortization (in years) March 31, 2015 December 31, 2014 March 31, 2014 Regulatory assets Deferred energy and fuel cost adjustments - current (a) (d) 1 $ 30,833 $ 23,820 $ 23,935 Deferred gas cost adjustments (a)(d) 2 6,138 37,471 38,505 Gas price derivatives (a) 7 21,606 18,740 4,420 AFUDC (b) 45 12,114 12,358 12,349 Employee benefit plans (c) (e) 12 97,700 97,126 65,833 Environmental (a) subject to approval 1,240 1,314 1,317 Asset retirement obligations (a) 44 3,237 3,287 3,271 Bond issue cost (a) 23 3,240 3,276 3,383 Renewable energy standard adjustment (a) 5 5,590 9,622 16,088 Flow through accounting (c) 35 26,835 25,887 21,837 Decommissioning costs 10 13,702 12,484 — Other regulatory assets (a) 15 13,242 12,454 10,181 $ 235,477 $ 257,839 $ 201,119 Regulatory liabilities Deferred energy and gas costs (a) (d) 1 $ 18,094 $ 6,496 $ 6,485 Employee benefit plans (c) (e) 12 53,151 53,139 34,355 Cost of removal (a) 44 81,449 78,249 67,640 Other regulatory liabilities (c) 25 13,845 10,947 8,896 $ 166,539 $ 148,831 $ 117,376 __________ (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) Our deferred energy, fuel cost, and gas cost adjustments represent the cost of electricity and gas delivered to our electric and gas utility customers that is either higher or lower than current rates and will be recovered or refunded in future rates. Fluctuations in deferred gas cost adjustments compared to the same period in the prior year are primarily due to higher natural gas prices driven by demand and market conditions from the peak winter heating season in the first part of 2014. Our electric and gas utilities file periodic quarterly, semi-annual, and/or annual filings to recover these costs based on the respective cost mechanisms approved by their applicable state utility commissions. (e) Increase compared to March 31, 2014 is due to a decrease in the discount rate and a change in the mortality tables used in employee benefit plan estimates.

Materials, Supplies and Fuel_

Materials, Supplies and Fuel:	3 Months Ended
	Mar. 31, 2015
Inventory, Net [Abstract]
Materials, Supplies and Fuel	MATERIALS, SUPPLIES AND FUEL The following amounts by major classification are included in Materials, supplies and fuel in the accompanying Condensed Consolidated Balance Sheets (in thousands) as of: March 31, 2015 December 31, 2014 March 31, 2014 Materials and supplies $ 52,429 $ 49,555 $ 50,727 Fuel - Electric Utilities 6,780 6,637 7,218 Natural gas in storage held for distribution 7,417 34,999 8,242 Total materials, supplies and fuel $ 66,626 $ 91,191 $ 66,187

Earnings Per Share_

Earnings Per Share:	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE A reconciliation of share amounts used to compute Earnings (loss) per share in the accompanying Condensed Consolidated Statements of Income (loss) is as follows (in thousands): Three Months Ended March 31, 2015 2014 Net income (loss) available for common stock $ 33,850 $ 48,645 Weighted average shares - basic 44,541 44,330 Dilutive effect of: Equity compensation 119 224 Weighted average shares - diluted 44,660 44,554 The following outstanding securities were not included in the computation of diluted earnings per share as their effect would have been anti-dilutive (in thousands): Three Months Ended March 31, 2015 2014 Equity compensation 107 46 Anti-dilutive shares 107 46

Notes Payable and Long-term Deb

Notes Payable and Long-term Debt:	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Notes Payable and Long-term debt	NOTES PAYABLE AND LONG-TERM DEBT We had the following short-term debt outstanding in the accompanying Condensed Consolidated Balance Sheets (in thousands) as of: March 31, 2015 December 31, 2014 March 31, 2014 Balance Outstanding Letters of Credit Balance Outstanding Letters of Credit Balance Outstanding Letters of Credit Revolving Credit Facility $ 102,600 $ 22,300 $ 75,000 $ 35,000 $ 100,000 $ 27,700 Revolving Credit Facility On May 29, 2014, we amended our $500 million corporate Revolving Credit Facility agreement to extend the term through May 29, 2019 . This facility is substantially similar to the former agreement, which includes an accordion feature that allows us, with the consent of the administrative agent and issuing agents, to increase the capacity of the facility to $750 million . Borrowings continue to be available under a base rate or various Eurodollar rate options. The interest costs associated with the letters of credit or borrowings and the commitment fee under the Revolving Credit Facility are determined based upon our most favorable Corporate credit rating from S&P and Moody’s for our unsecured debt. Based on our credit ratings, the margins for base rate borrowings, Eurodollar borrowings, and letters of credit were 0.125% , 1.125% , and 1.125% , respectively at March 31, 2015 . A commitment fee is charged on the unused amount of the Revolving Credit Facility and was 0.175% based on our credit rating. Replacement of Corporate Term Loan On April 13, 2015, we entered into a new $300 million Corporate term loan expiring April 12, 2017 . This new term loan replaced the $275 million Corporate term loan due on June 19, 2015 . In accordance with the terms of the agreement, the $275 million Corporate term loan is classified as Long-Term Debt as of March 31, 2015 . The additional $25 million , less interest and fees, will be used for general corporate purposes. The cost of the borrowing under the new term loan is LIBOR plus a margin of 0.9% . The covenants on the new term loan are substantially the same as the revolving credit facility. Debt Covenants Our Revolving Credit Facility and our Term Loan require compliance with the following financial covenant at the end of each quarter: As of March 31, 2015 Covenant Requirement Recourse Leverage Ratio 55% Less than 65% As of March 31, 2015 , we were in compliance with this covenant.

Risk Management Activities_

Risk Management Activities:	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Risk Management Activities	RISK MANAGEMENT ACTIVITIES Our activities in the regulated and non-regulated energy sectors expose us to a number of risks in the normal operation of our businesses. Depending on the activity, we are exposed to varying degrees of market risk and credit risk. To manage and mitigate these identified risks, we have adopted the Black Hills Corporation Risk Policies and Procedures as discussed in our 2014 Annual Report on Form 10-K/A. Market Risk Market risk is the potential loss that might occur as a result of an adverse change in market price or rate. We are exposed to the following market risks including, but not limited to: • Commodity price risk associated with our natural long position in crude oil and natural gas reserves and production; and our fuel procurement for certain of our gas-fired generation assets; and • Interest rate risk associated with our variable-rate debt. Credit Risk Credit risk is the risk of financial loss resulting from non-performance of contractual obligations by a counterparty. For production and generation activities, we attempt to mitigate our credit exposure by conducting business primarily with high credit quality entities, setting tenor and credit limits commensurate with counterparty financial strength, obtaining master netting agreements, and mitigating credit exposure with less creditworthy counterparties through parental guarantees, prepayments, letters of credit, and other security agreements. We perform ongoing credit evaluations of our customers and adjust credit limits based upon payment history and the customer’s current creditworthiness, as determined by review of their current credit information. We maintain a provision for estimated credit losses based upon historical experience and any specific customer collection issue that is identified. Our derivative and hedging activities recorded in the accompanying Condensed Consolidated Balance Sheets, Condensed Consolidated Statements of Income (Loss) and Condensed Consolidated Statements of Comprehensive Income (Loss) are detailed below and in Note 9 . Oil and Gas We produce natural gas, NGLs and crude oil through our exploration and production activities. Our natural long positions, or unhedged open positions, result in commodity price risk and variability to our cash flows. To mitigate commodity price risk and preserve cash flows, we primarily use exchange traded futures and related options to hedge portions of our crude oil and natural gas production. We elect hedge accounting on these instruments. These transactions were designated at inception as cash flow hedges, documented under accounting standards for derivatives and hedging, and initially met prospective effectiveness testing. Effectiveness of our hedging position is evaluated at least quarterly. The derivatives were marked to fair value and were recorded as Derivative assets or Derivative liabilities on the accompanying Condensed Consolidated Balance Sheets, net of balance sheet offsetting as permitted by GAAP. The effective portion of the gain or loss on these derivatives for which we have elected cash flow hedge accounting is reported in AOCI in the accompanying Condensed Consolidated Balance Sheets and the ineffective portion, if any, is reported in Revenue in the accompanying Condensed Consolidated Statements of Income (Loss). The contract or notional amounts, terms of our commodity derivatives, and the derivative balances for our Oil and Gas segment reflected on the Condensed Consolidated Balance Sheets were as follows (dollars in thousands) as of: March 31, 2015 December 31, 2014 March 31, 2014 Crude Oil Futures, Swaps and Options Natural Gas Futures and Swaps Crude Oil Futures, Swaps and Options Natural Gas Futures and Swaps Crude Oil Futures, Swaps and Options Natural Gas Futures and Swaps Notional (a) 305,000 5,367,500 334,500 6,582,500 442,500 8,296,250 Maximum terms in months (b) 1 1 1 1 1 1 Derivative assets, current $ — $ — $ — $ — $ — $ — Derivative assets, non-current $ — $ — $ — $ — $ — $ — Derivative liabilities, current $ — $ — $ — $ — $ — $ — Derivative liabilities, non-current $ — $ — $ — $ — $ — $ — __________ (a) Crude oil in Bbls, natural gas in MMBtus. (b) Refers to the tenor of the derivative instrument. Assets and liabilities are classified as current/non-current based on the production month hedged and the corresponding settlement of the derivative instrument. Based on March 31, 2015 , prices a $9.9 million gain would be reclassified from AOCI over the next 12 months. Estimated and actual realized gains or losses will change during future periods as market prices fluctuate. Utilities The operations of our utilities, including natural gas sold by our Gas Utilities and natural gas used for Electric Utility generation plants or those plants under PPAs where our Electric Utilities must provide the generation fuel (tolling agreements), expose our utility customers to volatility in natural gas prices. Therefore, as allowed or required by state utility commissions, we have entered into commission approved hedging programs utilizing natural gas futures, options and basis swaps to reduce our customers’ underlying exposure to these fluctuations. These transactions are considered derivatives, and in accordance with accounting standards for derivatives and hedging, mark-to-market adjustments are recorded as Derivative assets or Derivative liabilities on the accompanying Condensed Consolidated Balance Sheets, net of balance sheet offsetting as permitted by GAAP. Unrealized and realized gains and losses, as well as option premiums and commissions on these transactions are recorded as Regulatory assets or Regulatory liabilities in the accompanying Condensed Consolidated Balance Sheets in accordance with state commission guidelines. When the related costs are recovered through our rates, the hedging activity is recognized in the Condensed Consolidated Statements of Income (Loss), or the Condensed Consolidated Statements of Comprehensive Income (Loss). The contract or notional amounts and terms of the natural gas derivative commodity instruments held at our Utilities were as follows, as of: March 31, 2015 December 31, 2014 March 31, 2014 Notional (MMBtus) Maximum Term (months) (a) Notional (MMBtus) Maximum Term (months) (a) Notional (MMBtus) Maximum Term (months) (a) Natural gas futures purchased 17,280,000 69 19,370,000 72 16,140,000 80 Natural gas options purchased 1,320,000 12 4,020,000 8 1,320,000 12 Natural gas basis swaps purchased 15,735,000 57 12,005,000 60 14,575,000 69 __________ (a) Term reflects the maximum forward period hedged. We had the following derivative balances related to the hedges in our Utilities reflected in our Condensed Consolidated Balance Sheets as of (in thousands): March 31, 2015 December 31, 2014 March 31, 2014 Derivative assets, current $ — $ — $ 1,846 Derivative assets, non-current $ — $ — $ — Derivative liabilities, non-current $ — $ — $ — Net unrealized (gain) loss included in Regulatory assets or Regulatory liabilities $ 21,606 $ 18,740 $ 4,420 Financing Activities We entered into floating-to-fixed interest rate swap agreements to reduce our exposure to interest rate fluctuations associated with our floating rate debt obligations. The contract or notional amounts, terms of our interest rate swaps and the interest rate swaps balances reflected on the Condensed Consolidated Balance Sheets were as follows (dollars in thousands) as of: March 31, 2015 December 31, 2014 March 31, 2014 Interest Rate Swaps (a) Interest Rate Swaps (a) Interest Rate Swaps (a) Notional $ 75,000 $ 75,000 $ 75,000 Weighted average fixed interest rate 4.97 % 4.97 % 4.97 % Maximum terms in years 1.75 2.00 2.75 Derivative liabilities, current $ 3,342 $ 3,340 $ 3,498 Derivative liabilities, non-current $ 2,143 $ 2,680 $ 4,805 __________ (a) These swaps are designated to borrowings on our Revolving Credit Facility, and are priced using three-month LIBOR, matching the floating portion of the related borrowings. Based on March 31, 2015 , market interest rates and balances related to our interest rate swaps, a loss of approximately $3.3 million would be realized, reported in pre-tax earnings and reclassified from AOCI during the next 12 months. Estimated and actual realized gains or losses will change during future periods as market interest rates change. Cash Flow Hedges The impacts of cash flow hedges on our Condensed Consolidated Statements of Income (Loss) were as follows (in thousands): Three Months Ended March 31, 2015 Derivatives in Cash Flow Hedging Relationships Amount of Gain/(Loss) Recognized in AOCI Derivative (Effective Portion) Location of Gain/(Loss) Reclassified from AOCI into Income (Effective Portion) Amount of Reclassified Gain/(Loss) from AOCI into Income (Effective Portion) Location of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion) Amount of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion) Interest rate swaps $ (886 ) Interest expense $ 1,437 $ — Commodity derivatives 3,764 Revenue (3,932 ) — Total $ 2,878 $ (2,495 ) $ — Three Months Ended March 31, 2014 Derivatives in Cash Flow Hedging Relationships Amount of Gain/(Loss) Recognized in AOCI Derivative (Effective Portion) Location of Gain/(Loss) Reclassified from AOCI into Income (Effective Portion) Amount of Reclassified Gain/(Loss) from AOCI into Income (Effective Portion) Location of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion) Amount of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion) Interest rate swaps $ (91 ) Interest expense $ (894 ) $ — Commodity derivatives (3,473 ) Revenue (311 ) — Total $ (3,564 ) $ (1,205 ) $ —

Fair Value Measurements_

Fair Value Measurements:	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS Derivative Financial Instruments The accounting guidance for fair value measurements requires certain disclosures about assets and liabilities measured at fair value. This guidance establishes a hierarchical framework for disclosing the observability of the inputs utilized in measuring assets and liabilities at fair value. 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. For additional information see Notes 1, 8, 9 and 10 to the Consolidated Financial Statements included in our 2014 Annual Report on Form 10-K/A filed with the SEC. 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. Valuation Methodologies for Derivatives Oil and Gas Segment: • The commodity contracts for our Oil and Gas segment are valued using the market approach and include exchange-traded futures and basis swaps. Fair value was derived using exchange quoted settlement prices from third party brokers for similar instruments as to quantity and timing. The prices are then validated through third-party sources and therefore support Level 2 disclosure. Utilities Segments: • The commodity contracts for our Utilities Segments, valued using the market approach, include exchange-traded futures, options and basis swaps (Level 2) for natural gas contracts. For Level 2 assets and liabilities, fair value was derived using broker quotes validated by the Chicago Mercantile Exchange pricing for similar instruments. Corporate Activities: • The interest rate swaps are valued using the market approach. We establish fair value by obtaining price quotes directly from the counterparty which are based on the floating three-month LIBOR curve for the term of the contract. The fair value obtained from the counterparty is then validated by utilizing a nationally recognized service that obtains observable inputs to compute fair value for the same instrument. In addition, the fair value for the interest rate swap derivatives includes a CVA component. The CVA considers the fair value of the interest rate swap and the probability of default based on the life of the contract. For the probability of a default component, we utilize observable inputs supporting a Level 2 disclosure by using our credit default spread, if available, or a generic credit default spread curve that takes into account our credit ratings. Recurring Fair Value Measurements There have been no significant transfers between Level 1 and Level 2 derivative balances. Amounts included in cash collateral and counterparty netting in the following tables represent the impact of legally enforceable master netting agreements that allow us to settle positive and negative positions, netting of asset and liability positions permitted in accordance with accounting standards for offsetting as well as cash collateral posted with the same counterparties. The following tables set forth by level within the fair value hierarchy our gross assets and gross liabilities and related offsetting as permitted by GAAP that were accounted for at fair value on a recurring basis for derivative instruments. A discussion of fair value of financial instruments is included in Note 10 : As of March 31, 2015 Level 1 Level 2 Level 3 Cash Collateral and Counterparty Netting Total (in thousands) Assets: Commodity derivatives — Oil and Gas Options -- Oil $ — $ — $ — $ — $ — Basis Swaps -- Oil — 8,096 — (8,096 ) — Options -- Gas — — — — — Basis Swaps -- Gas — 6,526 — (6,526 ) — Commodity derivatives — Utilities — 1,184 — (1,184 ) — Total $ — $ 15,806 $ — $ (15,806 ) $ — Liabilities: Commodity derivatives — Oil and Gas Options -- Oil $ — $ — $ — $ — $ — Basis Swaps -- Oil — 2 — (2 ) — Options -- Gas — — — — — Basis Swaps -- Gas — 256 — (256 ) — Commodity derivatives — Utilities — 22,002 — (22,002 ) — Interest rate swaps — 5,485 — — 5,485 Total $ — $ 27,745 $ — $ (22,260 ) $ 5,485 As of December 31, 2014 Level 1 Level 2 Level 3 Cash Collateral and Counterparty Netting Total (in thousands) Assets: Commodity derivatives — Oil and Gas Options -- Oil $ — $ — $ — $ — $ — Basis Swaps -- Oil — 8,599 — (8,599 ) — Options -- Gas — — — — — Basis Swaps -- Gas — 6,558 — (6,558 ) — Commodity derivatives —Utilities — 2,389 — (2,389 ) — Total $ — $ 17,546 $ — $ (17,546 ) $ — Liabilities: Commodity derivatives — Oil and Gas Options -- Oil $ — $ — $ — $ — $ — Basis Swaps -- Oil — — — — — Options -- Gas — — — — — Basis Swaps -- Gas — 473 — (473 ) — Commodity derivatives — Utilities — 19,303 — (19,303 ) — Interest rate swaps — 6,020 — — 6,020 Total $ — $ 25,796 $ — $ (19,776 ) $ 6,020 As of March 31, 2014 Level 1 Level 2 Level 3 Cash Collateral and Counterparty Netting Total (in thousands) Assets: Commodity derivatives — Oil and Gas Options -- Oil $ — $ — $ — $ — $ — Basis Swaps -- Oil — 7 — (7 ) — Options -- Gas — — — — — Basis Swaps -- Gas — 490 — (490 ) — Commodity derivatives — Utilities — 3,226 — (1,380 ) 1,846 Total $ — $ 3,723 $ — $ (1,877 ) $ 1,846 Liabilities: Commodity derivatives — Oil and Gas Options -- Oil $ — $ — $ — $ — $ — Basis Swaps -- Oil — 1,983 — (1,983 ) — Options -- Gas — — — — — Basis Swaps -- Gas — 2,114 — (2,114 ) — Commodity derivatives — Utilities — 6,919 — (6,919 ) — Interest rate swaps — 8,303 — — 8,303 Total $ — $ 19,319 $ — $ (11,016 ) $ 8,303 Fair Value Measures by Balance Sheet Classification As required by accounting standards for derivatives and hedges, fair values within the following tables are presented on a gross basis reflecting the netting of asset and liability positions permitted in accordance with accounting standards for offsetting and under terms of our master netting agreements and the impact of legally enforceable master netting agreements that allow us to settle positive and negative positions; however, the amounts do not include net cash collateral on deposit in margin accounts at March 31, 2015 , December 31, 2014 , and March 31, 2014 , to collateralize certain financial instruments, which are included in Derivative assets and/or Derivative liabilities. Therefore, the balances are not indicative of either our actual credit exposure or net economic exposure. Additionally, the amounts below will not agree with the amounts presented on our Condensed Consolidated Balance Sheets, nor will they correspond to the fair value measurements presented in Note 8 . The following tables present the fair value and balance sheet classification of our derivative instruments (in thousands): As of March 31, 2015 Balance Sheet Location Fair Value of Asset Derivatives Fair Value of Liability Derivatives Derivatives designated as hedges: Commodity derivatives Derivative assets — current $ 9,989 $ — Commodity derivatives Derivative assets — non-current 4,633 — Commodity derivatives Derivative liabilities — current — 126 Commodity derivatives Derivative liabilities — non-current — 132 Interest rate swaps Derivative liabilities — current — 3,342 Interest rate swaps Derivative liabilities — non-current — 2,143 Total derivatives designated as hedges $ 14,622 $ 5,743 Derivatives not designated as hedges: Commodity derivatives Derivative assets — current $ — $ — Commodity derivatives Derivative assets — non-current — — Commodity derivatives Derivative liabilities — current — 7,530 Commodity derivatives Derivative liabilities — non-current — 13,288 Total derivatives not designated as hedges $ — $ 20,818 As of December 31, 2014 Balance Sheet Location Fair Value of Asset Derivatives Fair Value of Liability Derivatives Derivatives designated as hedges: Commodity derivatives Derivative assets — current $ 10,391 $ — Commodity derivatives Derivative assets — non-current 4,766 — Commodity derivatives Derivative liabilities — current — 185 Commodity derivatives Derivative liabilities — non-current — 288 Interest rate swaps Derivative liabilities — current — 3,340 Interest rate swaps Derivative liabilities — non-current — 2,680 Total derivatives designated as hedges $ 15,157 $ 6,493 Derivatives not designated as hedges: Commodity derivatives Derivative assets — current $ — $ — Commodity derivatives Derivative assets — non-current — — Commodity derivatives Derivative liabilities — current — 8,032 Commodity derivatives Derivative liabilities — non-current — 8,882 Total derivatives not designated as hedges $ — $ 16,914 As of March 31, 2014 Balance Sheet Location Fair Value of Asset Derivatives Fair Value of Liability Derivatives Derivatives designated as hedges: Commodity derivatives Derivative assets — current $ 30 $ — Commodity derivatives Derivative assets — non-current 466 — Commodity derivatives Derivative liabilities — current — 3,187 Commodity derivatives Derivative liabilities — non-current — 910 Interest rate swaps Derivative liabilities — current — 3,498 Interest rate swaps Derivative liabilities — non-current — 4,805 Total derivatives designated as hedges $ 496 $ 12,400 Derivatives not designated as hedges: Commodity derivatives Derivative assets — current $ 1,846 $ — Commodity derivatives Derivative assets — non-current — — Commodity derivatives Derivative liabilities — current — — Commodity derivatives Derivative liabilities — non-current — 5,539 Interest rate swaps Derivative liabilities — current — — Interest rate swaps Derivative liabilities — non-current — — Total derivatives not designated as hedges $ 1,846 $ 5,539

Fair Value of Financial Instrum

Fair Value of Financial Instruments:	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	FAIR VALUE OF FINANCIAL INSTRUMENTS The estimated fair values of our financial instruments, excluding derivatives which are presented in Note 9 , were as follows (in thousands) as of: March 31, 2015 December 31, 2014 March 31, 2014 Carrying Amount Fair Value Carrying Amount Fair Value Carrying Amount Fair Value Cash and cash equivalents (a) $ 63,385 $ 63,385 $ 21,218 $ 21,218 $ 17,641 $ 17,641 Restricted cash and equivalents (a) $ 2,191 $ 2,191 $ 2,056 $ 2,056 $ 2 $ 2 Notes payable (a) $ 102,600 $ 102,600 $ 75,000 $ 75,000 $ 100,000 $ 100,000 Long-term debt, including current maturities (b) $ 1,542,658 $ 1,767,113 $ 1,542,589 $ 1,734,555 $ 1,396,949 $ 1,541,727 __________ (a) Carrying value approximates fair value due to either the 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 based on observable inputs available either directly or indirectly for similar liabilities in active markets and therefore is classified in Level 2 in the fair value hierarchy.

Other Comprehensive Income (Los

Other Comprehensive Income (Loss):	3 Months Ended
	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Other Comprehensive Income (Loss)	OTHER COMPREHENSIVE INCOME (LOSS) The components of the reclassification adjustments, net of tax, included in Other Comprehensive Income (Loss) for the periods were as follows (in thousands): Location on the Condensed Consolidated Statements of Income (Loss) Amount Reclassified from AOCI Three Months Ended March 31, 2015 March 31, 2014 Gains (losses) on cash flow hedges: Interest rate swaps Interest expense $ 1,437 $ 894 Commodity contracts Revenue (3,932 ) 311 (2,495 ) 1,205 Income tax Income tax benefit (expense) 1,254 (425 ) Reclassification adjustments related to cash flow hedges, net of tax $ (1,241 ) $ 780 Amortization of defined benefit plans: Prior service cost Utilities - Operations and maintenance $ (27 ) $ (25 ) Non-regulated energy operations and maintenance (28 ) 12 Actuarial gain (loss) Utilities - Operations and maintenance 454 157 Non-regulated energy operations and maintenance 251 85 650 229 Income tax Income tax benefit (expense) (228 ) (81 ) Reclassification adjustments related to defined benefit plans, net of tax $ 422 $ 148 Balances by classification included within Accumulated other comprehensive income (loss) on the accompanying Condensed Consolidated Balance Sheets are as follows (in thousands): Derivatives Designated as Cash Flow Hedges Employee Benefit Plans Total Balance as of December 31, 2013 $ (7,133 ) $ (10,289 ) $ (17,422 ) Other comprehensive income (loss), net of tax (1,478 ) 311 (1,167 ) Balance as of March 31, 2014 $ (8,611 ) $ (9,978 ) $ (18,589 ) Balance as of December 31, 2014 $ 5,093 $ (20,137 ) $ (15,044 ) Other comprehensive income (loss), net of tax 595 395 990 Balance as of March 31, 2015 $ 5,688 $ (19,742 ) $ (14,054 )

Supplemental Disclosure of Cash

Supplemental Disclosure of Cash Flow Information:	3 Months Ended
	Mar. 31, 2015
Supplemental Cash Flow Information [Abstract]
Supplemental Disclosure of Cash Flow Information	SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION Three months ended March 31, 2015 March 31, 2014 (in thousands) Non-cash investing and financing activities from continuing operations— Property, plant and equipment acquired with accrued liabilities $ 33,534 $ 40,939 Increase (decrease) in capitalized assets associated with asset retirement obligations $ — $ (2,785 ) Cash (paid) refunded during the period for continuing operations— Interest (net of amounts capitalized) $ (10,909 ) $ (11,452 ) Income taxes, net $ (2 ) $ 4

Employee Benefit Plans_

Employee Benefit Plans:	3 Months Ended
	Mar. 31, 2015
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS Defined Benefit Pension Plans The components of net periodic benefit cost for the Defined Benefit Pension Plans were as follows (in thousands): Three Months Ended March 31, 2015 2014 Service cost $ 1,494 $ 1,362 Interest cost 3,880 3,963 Expected return on plan assets (4,867 ) (4,516 ) Prior service cost 15 16 Net loss (gain) 2,759 1,201 Net periodic benefit cost $ 3,281 $ 2,026 Defined Benefit Postretirement Healthcare Plans The components of net periodic benefit cost for the Defined Benefit Postretirement Healthcare Plans were as follows (in thousands): Three Months Ended March 31, 2015 2014 Service cost $ 464 $ 425 Interest cost 450 479 Expected return on plan assets (33 ) (21 ) Prior service cost (benefit) (107 ) (107 ) Net loss (gain) 102 40 Net periodic benefit cost $ 876 $ 816 Supplemental Non-qualified Defined Benefit and Defined Contribution Plans The components of net periodic benefit cost for the Supplemental Non-qualified Defined Benefit and Defined Contribution Plans were as follows (in thousands): Three Months Ended March 31, 2015 2014 Service cost $ 491 $ 374 Interest cost 364 362 Prior service cost 1 1 Net loss (gain) 270 124 Net periodic benefit cost $ 1,126 $ 861 Contributions We anticipate that we will make contributions to the benefit plans during 2015 and 2016 . Contributions to the Defined Benefit Pension Plans are cash contributions made directly to the Pension Plan Trust accounts. Contributions to the Healthcare and Supplemental Plan are made in the form of benefit payments. Contributions and anticipated contributions are as follows (in thousands): Contributions Made Additional Contributions Contributions Three Months Ended March 31, 2015 Anticipated for 2015 Anticipated for 2016 Defined Benefit Pension Plans $ — $ 10,200 $ 10,200 Non-pension Defined Benefit Postretirement Healthcare Plans $ 939 $ 2,816 $ 4,026 Supplemental Non-qualified Defined Benefit and Defined Contribution Plans $ 372 $ 1,115 $ 1,544

Commitments and Contingencies_

Commitments and Contingencies:	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES There have been no significant changes to commitments and contingencies from those previously disclosed in Note 18 of our Notes to the Consolidated Financial Statements in our 2014 Annual Report on Form 10-K/A except for those described below. Oil Creek Fire On June 29, 2012 , a forest and grassland fire occurred in the western Black Hills of Wyoming. A fire investigator retained by the Weston County Fire Protection District concluded that the fire was caused by the failure of a transmission structure owned, operated and maintained by Black Hills Power. On April 16, 2013, a large group of private landowners filed suit in the United States District Court for the District of Wyoming. There are approximately 36 Plaintiff groups (including property jointly owned by multiple family members or entities), or approximately 73 individually named private plaintiffs. In addition, the State of Wyoming has intervened in the lawsuit. Both the private landowners and the State of Wyoming assert claims for damages against Black Hills Power. The claims include allegations of negligence, negligence per se, common law nuisance and trespass. In addition to claims for compensatory damages, the lawsuit seeks recovery of punitive damages. We have denied and will vigorously defend all claims arising out of the fire. We cannot predict the outcome of expert investigation, the viability of alleged claims or the outcome of the litigation. Civil litigation of this kind, however, is likely to lead to settlement negotiations, including negotiations prompted by pre-trial civil court procedures. We believe such negotiations would effect a settlement of all claims. Regardless of whether the litigation is determined at trial or through settlement, we expect to incur significant investigation, legal and expert services expenses associated with the litigation. We maintain insurance coverage to limit our exposure to losses due to civil liability claims, and related litigation expense, and we will pursue recoveries to the maximum extent available under the policies. The deductible applicable to some types of claims arising out of this fire is $1.0 million . Based upon information currently available, we believe that a loss associated with settlement of pending claims is probable. Accordingly, we recorded a loss contingency liability related to these claims and we recorded a receivable for costs we believe are reimbursable and probable of recovery under our insurance coverage. Both of these entries reflect our reasonable estimate of probable future litigation expense and settlement costs; we did not base these contingencies on any determination that it is probable we would be found liable for these claims were they to be litigated. Given the uncertainty of litigation, however, a loss related to the fire, the litigation and related claims in excess of the loss we have determined to be probable is reasonably possible. We cannot reasonably estimate the amount of such possible loss because expert investigations and our review of damage claim documentation are ongoing, and there are significant factual and legal issues to be resolved. Further claims may be presented by these claimants and other parties. We have received claims seeking recovery for fire suppression, reclamation and rehabilitation costs, damage to fencing and other personal property, alleged injury to timber, grass or hay, livestock and related operations, and diminished value of real estate. Based on the legal standard for measuring damages that we believe applies to this matter, we estimate the current total claims to be approximately $55 million ; however the actual amount of allowed claims and any loss will depend on the resolution of certain factual and legal issues. We are not yet able to reasonably estimate the amount of any reasonable possible losses in excess of the amount we have accrued. Based upon information currently available, however, management does not expect the outcome of the claims to have a material adverse effect upon our consolidated financial condition, results of operations or cash flows. Dividend Restrictions Our Revolving Credit Facility and other debt obligations contain restrictions on the payment of cash dividends upon a default or event of default. As of March 31, 2015 , we were in compliance with the debt covenants. Due to our holding company structure, substantially all of our operating cash flows are provided by dividends paid or distributions made by our subsidiaries. The cash to pay dividends to our stockholders is derived from these cash flows. As a result, certain statutory limitations or regulatory or financing agreements could affect the levels of distributions allowed to be made by our subsidiaries. The following restrictions on distributions from our subsidiaries existed at March 31, 2015 : • Our utilities are generally limited to the amount of dividends allowed to be paid to us as a utility holding company under the Federal Power Act and settlement agreements with state regulatory jurisdictions. As of March 31, 2015 , the restricted net assets at our Utilities Group were approximately $338 million .

Impairment of Long-lived Assets

Impairment of Long-lived Assets (Notes)	3 Months Ended
	Mar. 31, 2015
Asset Impairment Charges [Abstract]
Asset Impairment Charges [Text Block]	IMPAIRMENT OF LONG-LIVED ASSETS Our Oil and Gas segment accounts for oil and gas activities under the full cost method of accounting. Under the full cost method, all productive and non-productive costs related to acquisition, exploration, development, abandonment and reclamation activities are capitalized. These capitalized costs, less accumulated amortization and related deferred income taxes, are subject to a ceiling test which limits the pooled costs to the aggregate of the discounted value of future net revenue attributable to proved natural gas and crude oil reserves using a discount rate defined by the SEC plus the lower of cost or market value of unevaluated properties. This method values the reserves based upon SEC-defined prices for oil and gas as of the end of each reporting period adjusted for contracted price changes. Any costs in excess of the ceiling are written off as a non-cash charge. During the first quarter of 2015, we recorded a $22 million non-cash impairment of oil and gas assets included in our Oil and Gas segment. In determining the ceiling value of our assets under the full cost accounting rules of the SEC, we utilized the average of the quoted prices from the first day of each month from the previous 12 months. For natural gas, the average NYMEX price was $3.88 per Mcf, adjusted to $2.69 per Mcf at the wellhead; for crude oil, the average NYMEX price was $82.72 per barrel, adjusted to $74.13 per barrel at the wellhead.

Management Statement (continu23

Management Statement (continued) Revision of Prior Period Financial Statements (Tables)	3 Months Ended
	Mar. 31, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]	CONDENSED CONSOLIDATED STATEMENTS OF INCOME For the Three Months Ended March 31, 2015 As Reported Adjustments As Revised (in thousands) Depreciation, depletion and amortization $ 39,586 $ (584 ) $ 39,002 Impairment of long-lived assets $ — $ 22,036 $ 22,036 Total operating expenses $ 350,035 $ 21,452 $ 371,487 Operating income (loss) $ 91,952 $ (21,452 ) $ 70,500 Income (loss) before earnings (loss) of unconsolidated subsidiaries and income taxes $ 73,311 $ (21,452 ) $ 51,859 Income tax benefit (expense) $ (25,120 ) $ 7,408 $ (17,712 ) Net income (loss) available for common stock $ 47,894 $ (14,044 ) $ 33,850 Earnings (loss) per share of common stock: Earnings (loss) per share, Basic $ 1.08 $ (0.32 ) $ 0.76 Earnings (loss) per share, Diluted $ 1.07 $ (0.31 ) $ 0.76 For the Three Months Ended March 31, 2014 As Reported Adjustments As Revised (in thousands) Depreciation, depletion and amortization $ 36,083 $ (834 ) $ 35,249 Total operating expenses $ 370,571 $ (834 ) $ 369,737 Operating income (loss) $ 89,598 $ 834 $ 90,432 Income (loss) before earnings (loss) of unconsolidated subsidiaries and income taxes $ 73,485 $ 834 $ 74,319 Income tax benefit (expense) $ (25,366 ) $ (307 ) $ (25,673 ) Net income (loss) available for common stock $ 48,118 $ 527 $ 48,645 Earnings (loss) per share of common stock: Earnings (loss) per share, Basic - $ 1.09 $ 0.01 $ 1.10 Earnings (loss) per share, Diluted - $ 1.08 $ 0.01 $ 1.09 CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) For the Three Months Ended March 31, 2015 2014 (in thousands) As Reported Adjustments As Revised As Reported Adjustments As Revised Net income (loss) available for common stock $ 47,894 $ (14,044 ) $ 33,850 $ 48,118 $ 527 $ 48,645 Comprehensive income (loss) $ 48,884 $ (14,044 ) $ 34,840 $ 46,951 $ 527 $ 47,478 CONDENSED CONSOLIDATED BALANCE SHEET As of March 31, 2015 As of March 31, 2014 As Reported Adjustments As Revised As Reported Adjustments As Revised (in thousands) Accumulated depreciation and depletion $ (1,351,857 ) $ (55,357 ) $ (1,407,214 ) $ (1,298,398 ) $ (36,408 ) $ (1,334,806 ) Total property, plant and equipment, net $ 3,300,201 $ (55,357 ) $ 3,244,844 $ 3,019,796 $ (36,408 ) $ 2,983,388 TOTAL ASSETS $ 4,319,828 $ (55,357 ) $ 4,264,471 $ 3,964,964 $ (36,408 ) $ 3,928,556 Deferred income tax liability, non-current $ 522,290 $ (19,173 ) $ 503,117 $ 466,856 $ (12,687 ) $ 454,169 Total deferred credits and other liabilities $ 990,289 $ (19,173 ) $ 971,116 $ 830,861 $ (12,687 ) $ 818,174 Retained earnings $ 629,135 $ (36,184 ) $ 592,951 $ 570,963 $ (23,721 ) $ 547,242 Total stockholders' equity $ 1,407,767 $ (36,184 ) $ 1,371,583 $ 1,337,419 $ (23,721 ) $ 1,313,698 TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY $ 4,319,828 $ (55,357 ) $ 4,264,471 $ 3,964,964 $ (36,408 ) $ 3,928,556 CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS Three Months Ended March 31, 2015 Three Months Ended March 31, 2014 As Reported Adjustments As Revised As Reported Adjustments As Revised (in thousands) Net income (loss) available for common stock $ 47,894 $ (14,044 ) $ 33,850 $ 48,118 $ 527 $ 48,645 Adjustments to reconcile net income (loss) to net cash provided by operating activities: Depreciation, depletion and amortization $ 39,586 $ (584 ) $ 39,002 $ 36,083 $ (834 ) $ 35,249 Impairment of long-lived assets $ — $ 22,036 $ 22,036 $ — $ — $ — Deferred income taxes $ 22,048 $ (7,408 ) $ 14,640 $ 25,953 $ 307 $ 26,260 Net cash provided by (used in) operating activities $ 151,487 $ — $ 151,487 $ 98,098 $ — $ 98,098 The Notes to the Condensed Consolidated Financial Statements have been revised to reflect the correction of these errors for all periods presented.

Business Segment Information_ B

Business Segment Information: Business Segment Information (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting Information, Additional Information [Abstract]
Schedule of Segment Reporting Information	Segment information and Corporate activities included in the accompanying Condensed Consolidated Statements of Income (Loss) were as follows (in thousands): Three Months Ended March 31, 2015 External Operating Revenue Inter-company Operating Revenue Net Income (Loss) Utilities: Electric $ 182,974 $ 3,424 $ 18,929 Gas 237,651 — 22,212 Non-regulated Energy: Power Generation 1,953 20,721 8,145 Coal Mining 8,142 7,792 3,010 Oil and Gas (a) 11,267 — (19,115 ) Corporate activities — — 669 Inter-company eliminations — (31,937 ) — Total $ 441,987 $ — $ 33,850 ________________ (a) Net income (loss) includes ceiling test impairment (see Note 15 ) Three Months Ended March 31, 2014 External Operating Revenue Inter-company Operating Revenue Net Income (Loss) Utilities: Electric $ 178,095 $ 4,007 $ 14,575 Gas 259,337 — 24,698 Non-regulated Energy: Power Generation 1,269 21,079 8,073 Coal Mining 6,618 8,880 2,464 Oil and Gas 14,850 — (1,495 ) Corporate activities — — 330 Inter-company eliminations — (33,966 ) — Total $ 460,169 $ — $ 48,645
Reconciliation of Assets from Segment to Consolidated	Segment information and Corporate balances included in the accompanying Condensed Consolidated Balance Sheets were as follows (in thousands): Total Assets (net of inter-company eliminations) as of: March 31, 2015 December 31, 2014 March 31, 2014 Utilities: Electric (a) $ 2,817,423 $ 2,748,680 $ 2,572,616 Gas 839,802 906,922 842,660 Non-regulated Energy: Power Generation (a) 75,945 76,945 90,643 Coal Mining 77,399 74,407 74,523 Oil and Gas (b) 348,300 332,343 258,675 Corporate activities 105,602 106,605 89,439 Total assets $ 4,264,471 $ 4,245,902 $ 3,928,556 __________ (a) The PPA under which Black Hills Colorado IPP provides generation to support Colorado Electric customers from the Pueblo Airport Generation Station is accounted for as a capital lease. As such, assets owned by our Power Generation segment are recorded at Colorado Electric under accounting for a capital lease. (b) As a result of continued low commodity prices during 2015, we recorded a non-cash impairment of oil and gas assets included in our Oil and Gas segment of $22 million for the three months ended March 31, 2015. See Note 1 to the Condensed Consolidated Financial statements in this Quarterly Report on Form 10-Q/A.

Accounts Receivable_ Accounts R

Accounts Receivable: Accounts Receivable (Tables)	3 Months Ended
	Mar. 31, 2015
Receivables [Abstract]
Accounts Receivable and Allowance for Doubtful Accounts	Following is a summary of Accounts receivable, net included in the accompanying Condensed Consolidated Balance Sheets (in thousands) as of: Accounts Unbilled Less Allowance for Accounts March 31, 2015 Receivable, Trade Revenue Doubtful Accounts Receivable, net Electric Utilities $ 53,862 $ 24,540 $ (834 ) $ 77,568 Gas Utilities 63,252 28,785 (1,588 ) 90,449 Power Generation 1,152 — — 1,152 Coal Mining 3,638 — — 3,638 Oil and Gas 4,646 — (13 ) 4,633 Corporate 981 — — 981 Total $ 127,531 $ 53,325 $ (2,435 ) $ 178,421 Accounts Unbilled Less Allowance for Accounts December 31, 2014 Receivable, Trade Revenue Doubtful Accounts Receivable, net Electric Utilities $ 59,714 $ 26,474 $ (722 ) $ 85,466 Gas Utilities 47,394 45,546 (781 ) 92,159 Power Generation 1,369 — — 1,369 Coal Mining 3,151 — — 3,151 Oil and Gas 5,305 — (13 ) 5,292 Corporate 2,555 — — 2,555 Total $ 119,488 $ 72,020 $ (1,516 ) $ 189,992 Accounts Unbilled Less Allowance for Accounts March 31, 2014 Receivable, Trade Revenue Doubtful Accounts Receivable, net Electric Utilities $ 53,733 $ 20,063 $ (690 ) $ 73,106 Gas Utilities 77,982 35,791 (814 ) 112,959 Power Generation 1,340 — — 1,340 Coal Mining 2,616 — — 2,616 Oil and Gas 10,920 — (13 ) 10,907 Corporate 2,697 — — 2,697 Total $ 149,288 $ 55,854 $ (1,517 ) $ 203,625

Regulatory Accounting_ Regulato

Regulatory Accounting: Regulatory Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2015
Regulatory Assets and Liabilities Disclosure [Abstract]
Schedule of Regulatory Assets and Liabilities	We had the following regulatory assets and liabilities (in thousands): Maximum As of As of As of Amortization (in years) March 31, 2015 December 31, 2014 March 31, 2014 Regulatory assets Deferred energy and fuel cost adjustments - current (a) (d) 1 $ 30,833 $ 23,820 $ 23,935 Deferred gas cost adjustments (a)(d) 2 6,138 37,471 38,505 Gas price derivatives (a) 7 21,606 18,740 4,420 AFUDC (b) 45 12,114 12,358 12,349 Employee benefit plans (c) (e) 12 97,700 97,126 65,833 Environmental (a) subject to approval 1,240 1,314 1,317 Asset retirement obligations (a) 44 3,237 3,287 3,271 Bond issue cost (a) 23 3,240 3,276 3,383 Renewable energy standard adjustment (a) 5 5,590 9,622 16,088 Flow through accounting (c) 35 26,835 25,887 21,837 Decommissioning costs 10 13,702 12,484 — Other regulatory assets (a) 15 13,242 12,454 10,181 $ 235,477 $ 257,839 $ 201,119 Regulatory liabilities Deferred energy and gas costs (a) (d) 1 $ 18,094 $ 6,496 $ 6,485 Employee benefit plans (c) (e) 12 53,151 53,139 34,355 Cost of removal (a) 44 81,449 78,249 67,640 Other regulatory liabilities (c) 25 13,845 10,947 8,896 $ 166,539 $ 148,831 $ 117,376 __________ (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) Our deferred energy, fuel cost, and gas cost adjustments represent the cost of electricity and gas delivered to our electric and gas utility customers that is either higher or lower than current rates and will be recovered or refunded in future rates. Fluctuations in deferred gas cost adjustments compared to the same period in the prior year are primarily due to higher natural gas prices driven by demand and market conditions from the peak winter heating season in the first part of 2014. Our electric and gas utilities file periodic quarterly, semi-annual, and/or annual filings to recover these costs based on the respective cost mechanisms approved by their applicable state utility commissions. (e) Increase compared to March 31, 2014 is due to a decrease in the discount rate and a change in the mortality tables used in employee benefit plan estimates.

Materials, Supplies and Fuel_ M

Materials, Supplies and Fuel: Materials, Supplies and Fuel (Tables)	3 Months Ended
	Mar. 31, 2015
Inventory, Net [Abstract]
Materials, Supplies and Fuel	The following amounts by major classification are included in Materials, supplies and fuel in the accompanying Condensed Consolidated Balance Sheets (in thousands) as of: March 31, 2015 December 31, 2014 March 31, 2014 Materials and supplies $ 52,429 $ 49,555 $ 50,727 Fuel - Electric Utilities 6,780 6,637 7,218 Natural gas in storage held for distribution 7,417 34,999 8,242 Total materials, supplies and fuel $ 66,626 $ 91,191 $ 66,187

Earnings Per Share_ Earnings Pe

Earnings Per Share: Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share Reconciliation	A reconciliation of share amounts used to compute Earnings (loss) per share in the accompanying Condensed Consolidated Statements of Income (loss) is as follows (in thousands): Three Months Ended March 31, 2015 2014 Net income (loss) available for common stock $ 33,850 $ 48,645 Weighted average shares - basic 44,541 44,330 Dilutive effect of: Equity compensation 119 224 Weighted average shares - diluted 44,660 44,554
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following outstanding securities were not included in the computation of diluted earnings per share as their effect would have been anti-dilutive (in thousands): Three Months Ended March 31, 2015 2014 Equity compensation 107 46 Anti-dilutive shares 107 46

Notes Payable and Long-term D29

Notes Payable and Long-term Debt: Notes Payable and Long-term Debt (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Schedule of Short-term Debt	We had the following short-term debt outstanding in the accompanying Condensed Consolidated Balance Sheets (in thousands) as of: March 31, 2015 December 31, 2014 March 31, 2014 Balance Outstanding Letters of Credit Balance Outstanding Letters of Credit Balance Outstanding Letters of Credit Revolving Credit Facility $ 102,600 $ 22,300 $ 75,000 $ 35,000 $ 100,000 $ 27,700
Schedule of Credit Facility Covenants	Our Revolving Credit Facility and our Term Loan require compliance with the following financial covenant at the end of each quarter: As of March 31, 2015 Covenant Requirement Recourse Leverage Ratio 55% Less than 65%

Risk Management Activities_ Ris

Risk Management Activities: Risk Management Activities (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative [Line Items]
Schedule of Derivative Instruments	The contract or notional amounts, terms of our interest rate swaps and the interest rate swaps balances reflected on the Condensed Consolidated Balance Sheets were as follows (dollars in thousands) as of: March 31, 2015 December 31, 2014 March 31, 2014 Interest Rate Swaps (a) Interest Rate Swaps (a) Interest Rate Swaps (a) Notional $ 75,000 $ 75,000 $ 75,000 Weighted average fixed interest rate 4.97 % 4.97 % 4.97 % Maximum terms in years 1.75 2.00 2.75 Derivative liabilities, current $ 3,342 $ 3,340 $ 3,498 Derivative liabilities, non-current $ 2,143 $ 2,680 $ 4,805 __________ (a) These swaps are designated to borrowings on our Revolving Credit Facility, and are priced using three-month LIBOR, matching the floating portion of the related borrowings.
Derivative Instruments, Gain (Loss)	The impacts of cash flow hedges on our Condensed Consolidated Statements of Income (Loss) were as follows (in thousands): Three Months Ended March 31, 2015 Derivatives in Cash Flow Hedging Relationships Amount of Gain/(Loss) Recognized in AOCI Derivative (Effective Portion) Location of Gain/(Loss) Reclassified from AOCI into Income (Effective Portion) Amount of Reclassified Gain/(Loss) from AOCI into Income (Effective Portion) Location of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion) Amount of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion) Interest rate swaps $ (886 ) Interest expense $ 1,437 $ — Commodity derivatives 3,764 Revenue (3,932 ) — Total $ 2,878 $ (2,495 ) $ — Three Months Ended March 31, 2014 Derivatives in Cash Flow Hedging Relationships Amount of Gain/(Loss) Recognized in AOCI Derivative (Effective Portion) Location of Gain/(Loss) Reclassified from AOCI into Income (Effective Portion) Amount of Reclassified Gain/(Loss) from AOCI into Income (Effective Portion) Location of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion) Amount of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion) Interest rate swaps $ (91 ) Interest expense $ (894 ) $ — Commodity derivatives (3,473 ) Revenue (311 ) — Total $ (3,564 ) $ (1,205 ) $ —
Oil and Gas [Member]
Derivative [Line Items]
Schedule of Derivative Instruments	The contract or notional amounts, terms of our commodity derivatives, and the derivative balances for our Oil and Gas segment reflected on the Condensed Consolidated Balance Sheets were as follows (dollars in thousands) as of: March 31, 2015 December 31, 2014 March 31, 2014 Crude Oil Futures, Swaps and Options Natural Gas Futures and Swaps Crude Oil Futures, Swaps and Options Natural Gas Futures and Swaps Crude Oil Futures, Swaps and Options Natural Gas Futures and Swaps Notional (a) 305,000 5,367,500 334,500 6,582,500 442,500 8,296,250 Maximum terms in months (b) 1 1 1 1 1 1 Derivative assets, current $ — $ — $ — $ — $ — $ — Derivative assets, non-current $ — $ — $ — $ — $ — $ — Derivative liabilities, current $ — $ — $ — $ — $ — $ — Derivative liabilities, non-current $ — $ — $ — $ — $ — $ — __________ (a) Crude oil in Bbls, natural gas in MMBtus. (b) Refers to the tenor of the derivative instrument. Assets and liabilities are classified as current/non-current based on the production month hedged and the corresponding settlement of the derivative instrument.
Utilities Group [Member]
Derivative [Line Items]
Schedule of Derivative Instruments	We had the following derivative balances related to the hedges in our Utilities reflected in our Condensed Consolidated Balance Sheets as of (in thousands): March 31, 2015 December 31, 2014 March 31, 2014 Derivative assets, current $ — $ — $ 1,846 Derivative assets, non-current $ — $ — $ — Derivative liabilities, non-current $ — $ — $ — Net unrealized (gain) loss included in Regulatory assets or Regulatory liabilities $ 21,606 $ 18,740 $ 4,420
Contract or Notional Amounts and Terms of Commodity Derivatives	The contract or notional amounts and terms of the natural gas derivative commodity instruments held at our Utilities were as follows, as of: March 31, 2015 December 31, 2014 March 31, 2014 Notional (MMBtus) Maximum Term (months) (a) Notional (MMBtus) Maximum Term (months) (a) Notional (MMBtus) Maximum Term (months) (a) Natural gas futures purchased 17,280,000 69 19,370,000 72 16,140,000 80 Natural gas options purchased 1,320,000 12 4,020,000 8 1,320,000 12 Natural gas basis swaps purchased 15,735,000 57 12,005,000 60 14,575,000 69 __________ (a) Term reflects the maximum forward period hedged.

Fair Value Measurements_ Fair V

Fair Value Measurements: Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Schedule of Fair Value Hierarchy, Measured on Recurring Basis	The following tables set forth by level within the fair value hierarchy our gross assets and gross liabilities and related offsetting as permitted by GAAP that were accounted for at fair value on a recurring basis for derivative instruments. A discussion of fair value of financial instruments is included in Note 10 : As of March 31, 2015 Level 1 Level 2 Level 3 Cash Collateral and Counterparty Netting Total (in thousands) Assets: Commodity derivatives — Oil and Gas Options -- Oil $ — $ — $ — $ — $ — Basis Swaps -- Oil — 8,096 — (8,096 ) — Options -- Gas — — — — — Basis Swaps -- Gas — 6,526 — (6,526 ) — Commodity derivatives — Utilities — 1,184 — (1,184 ) — Total $ — $ 15,806 $ — $ (15,806 ) $ — Liabilities: Commodity derivatives — Oil and Gas Options -- Oil $ — $ — $ — $ — $ — Basis Swaps -- Oil — 2 — (2 ) — Options -- Gas — — — — — Basis Swaps -- Gas — 256 — (256 ) — Commodity derivatives — Utilities — 22,002 — (22,002 ) — Interest rate swaps — 5,485 — — 5,485 Total $ — $ 27,745 $ — $ (22,260 ) $ 5,485 As of December 31, 2014 Level 1 Level 2 Level 3 Cash Collateral and Counterparty Netting Total (in thousands) Assets: Commodity derivatives — Oil and Gas Options -- Oil $ — $ — $ — $ — $ — Basis Swaps -- Oil — 8,599 — (8,599 ) — Options -- Gas — — — — — Basis Swaps -- Gas — 6,558 — (6,558 ) — Commodity derivatives —Utilities — 2,389 — (2,389 ) — Total $ — $ 17,546 $ — $ (17,546 ) $ — Liabilities: Commodity derivatives — Oil and Gas Options -- Oil $ — $ — $ — $ — $ — Basis Swaps -- Oil — — — — — Options -- Gas — — — — — Basis Swaps -- Gas — 473 — (473 ) — Commodity derivatives — Utilities — 19,303 — (19,303 ) — Interest rate swaps — 6,020 — — 6,020 Total $ — $ 25,796 $ — $ (19,776 ) $ 6,020 As of March 31, 2014 Level 1 Level 2 Level 3 Cash Collateral and Counterparty Netting Total (in thousands) Assets: Commodity derivatives — Oil and Gas Options -- Oil $ — $ — $ — $ — $ — Basis Swaps -- Oil — 7 — (7 ) — Options -- Gas — — — — — Basis Swaps -- Gas — 490 — (490 ) — Commodity derivatives — Utilities — 3,226 — (1,380 ) 1,846 Total $ — $ 3,723 $ — $ (1,877 ) $ 1,846 Liabilities: Commodity derivatives — Oil and Gas Options -- Oil $ — $ — $ — $ — $ — Basis Swaps -- Oil — 1,983 — (1,983 ) — Options -- Gas — — — — — Basis Swaps -- Gas — 2,114 — (2,114 ) — Commodity derivatives — Utilities — 6,919 — (6,919 ) — Interest rate swaps — 8,303 — — 8,303 Total $ — $ 19,319 $ — $ (11,016 ) $ 8,303
Schedule of Derivative Instruments Balance Sheet Location	The following tables present the fair value and balance sheet classification of our derivative instruments (in thousands): As of March 31, 2015 Balance Sheet Location Fair Value of Asset Derivatives Fair Value of Liability Derivatives Derivatives designated as hedges: Commodity derivatives Derivative assets — current $ 9,989 $ — Commodity derivatives Derivative assets — non-current 4,633 — Commodity derivatives Derivative liabilities — current — 126 Commodity derivatives Derivative liabilities — non-current — 132 Interest rate swaps Derivative liabilities — current — 3,342 Interest rate swaps Derivative liabilities — non-current — 2,143 Total derivatives designated as hedges $ 14,622 $ 5,743 Derivatives not designated as hedges: Commodity derivatives Derivative assets — current $ — $ — Commodity derivatives Derivative assets — non-current — — Commodity derivatives Derivative liabilities — current — 7,530 Commodity derivatives Derivative liabilities — non-current — 13,288 Total derivatives not designated as hedges $ — $ 20,818 As of December 31, 2014 Balance Sheet Location Fair Value of Asset Derivatives Fair Value of Liability Derivatives Derivatives designated as hedges: Commodity derivatives Derivative assets — current $ 10,391 $ — Commodity derivatives Derivative assets — non-current 4,766 — Commodity derivatives Derivative liabilities — current — 185 Commodity derivatives Derivative liabilities — non-current — 288 Interest rate swaps Derivative liabilities — current — 3,340 Interest rate swaps Derivative liabilities — non-current — 2,680 Total derivatives designated as hedges $ 15,157 $ 6,493 Derivatives not designated as hedges: Commodity derivatives Derivative assets — current $ — $ — Commodity derivatives Derivative assets — non-current — — Commodity derivatives Derivative liabilities — current — 8,032 Commodity derivatives Derivative liabilities — non-current — 8,882 Total derivatives not designated as hedges $ — $ 16,914 As of March 31, 2014 Balance Sheet Location Fair Value of Asset Derivatives Fair Value of Liability Derivatives Derivatives designated as hedges: Commodity derivatives Derivative assets — current $ 30 $ — Commodity derivatives Derivative assets — non-current 466 — Commodity derivatives Derivative liabilities — current — 3,187 Commodity derivatives Derivative liabilities — non-current — 910 Interest rate swaps Derivative liabilities — current — 3,498 Interest rate swaps Derivative liabilities — non-current — 4,805 Total derivatives designated as hedges $ 496 $ 12,400 Derivatives not designated as hedges: Commodity derivatives Derivative assets — current $ 1,846 $ — Commodity derivatives Derivative assets — non-current — — Commodity derivatives Derivative liabilities — current — — Commodity derivatives Derivative liabilities — non-current — 5,539 Interest rate swaps Derivative liabilities — current — — Interest rate swaps Derivative liabilities — non-current — — Total derivatives not designated as hedges $ 1,846 $ 5,539

Fair Value of Financial Instr32

Fair Value of Financial Instruments: Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	The estimated fair values of our financial instruments, excluding derivatives which are presented in Note 9 , were as follows (in thousands) as of: March 31, 2015 December 31, 2014 March 31, 2014 Carrying Amount Fair Value Carrying Amount Fair Value Carrying Amount Fair Value Cash and cash equivalents (a) $ 63,385 $ 63,385 $ 21,218 $ 21,218 $ 17,641 $ 17,641 Restricted cash and equivalents (a) $ 2,191 $ 2,191 $ 2,056 $ 2,056 $ 2 $ 2 Notes payable (a) $ 102,600 $ 102,600 $ 75,000 $ 75,000 $ 100,000 $ 100,000 Long-term debt, including current maturities (b) $ 1,542,658 $ 1,767,113 $ 1,542,589 $ 1,734,555 $ 1,396,949 $ 1,541,727 __________ (a) Carrying value approximates fair value due to either the 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 based on observable inputs available either directly or indirectly for similar liabilities in active markets and therefore is classified in Level 2 in the fair value hierarchy.

Other Comprehensive Income (L33

Other Comprehensive Income (Loss): Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Reclassification Out of Accumulated Other Comprehensive Income (Loss)	The components of the reclassification adjustments, net of tax, included in Other Comprehensive Income (Loss) for the periods were as follows (in thousands): Location on the Condensed Consolidated Statements of Income (Loss) Amount Reclassified from AOCI Three Months Ended March 31, 2015 March 31, 2014 Gains (losses) on cash flow hedges: Interest rate swaps Interest expense $ 1,437 $ 894 Commodity contracts Revenue (3,932 ) 311 (2,495 ) 1,205 Income tax Income tax benefit (expense) 1,254 (425 ) Reclassification adjustments related to cash flow hedges, net of tax $ (1,241 ) $ 780 Amortization of defined benefit plans: Prior service cost Utilities - Operations and maintenance $ (27 ) $ (25 ) Non-regulated energy operations and maintenance (28 ) 12 Actuarial gain (loss) Utilities - Operations and maintenance 454 157 Non-regulated energy operations and maintenance 251 85 650 229 Income tax Income tax benefit (expense) (228 ) (81 ) Reclassification adjustments related to defined benefit plans, net of tax $ 422 $ 148
Schedule of Accumulated Other Comprehensive Income (Loss)	Balances by classification included within Accumulated other comprehensive income (loss) on the accompanying Condensed Consolidated Balance Sheets are as follows (in thousands): Derivatives Designated as Cash Flow Hedges Employee Benefit Plans Total Balance as of December 31, 2013 $ (7,133 ) $ (10,289 ) $ (17,422 ) Other comprehensive income (loss), net of tax (1,478 ) 311 (1,167 ) Balance as of March 31, 2014 $ (8,611 ) $ (9,978 ) $ (18,589 ) Balance as of December 31, 2014 $ 5,093 $ (20,137 ) $ (15,044 ) Other comprehensive income (loss), net of tax 595 395 990 Balance as of March 31, 2015 $ 5,688 $ (19,742 ) $ (14,054 )

Supplemental Disclosure of Ca34

Supplemental Disclosure of Cash Flow Information: Supplemental Disclosure of Cash Flow Information (Tables)	3 Months Ended
	Mar. 31, 2015
Supplemental Cash Flow Information [Abstract]
Supplemental Disclosure of Cash Flow Information	Three months ended March 31, 2015 March 31, 2014 (in thousands) Non-cash investing and financing activities from continuing operations— Property, plant and equipment acquired with accrued liabilities $ 33,534 $ 40,939 Increase (decrease) in capitalized assets associated with asset retirement obligations $ — $ (2,785 ) Cash (paid) refunded during the period for continuing operations— Interest (net of amounts capitalized) $ (10,909 ) $ (11,452 ) Income taxes, net $ (2 ) $ 4

Employee Benefit Plans_ Employe

Employee Benefit Plans: Employee Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2015
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 Plans were as follows (in thousands): Three Months Ended March 31, 2015 2014 Service cost $ 1,494 $ 1,362 Interest cost 3,880 3,963 Expected return on plan assets (4,867 ) (4,516 ) Prior service cost 15 16 Net loss (gain) 2,759 1,201 Net periodic benefit cost $ 3,281 $ 2,026 Defined Benefit Postretirement Healthcare Plans The components of net periodic benefit cost for the Defined Benefit Postretirement Healthcare Plans were as follows (in thousands): Three Months Ended March 31, 2015 2014 Service cost $ 464 $ 425 Interest cost 450 479 Expected return on plan assets (33 ) (21 ) Prior service cost (benefit) (107 ) (107 ) Net loss (gain) 102 40 Net periodic benefit cost $ 876 $ 816 Supplemental Non-qualified Defined Benefit and Defined Contribution Plans The components of net periodic benefit cost for the Supplemental Non-qualified Defined Benefit and Defined Contribution Plans were as follows (in thousands): Three Months Ended March 31, 2015 2014 Service cost $ 491 $ 374 Interest cost 364 362 Prior service cost 1 1 Net loss (gain) 270 124 Net periodic benefit cost $ 1,126 $ 861
Schedule of Defined Benefit Plans Contributions	Contributions and anticipated contributions are as follows (in thousands): Contributions Made Additional Contributions Contributions Three Months Ended March 31, 2015 Anticipated for 2015 Anticipated for 2016 Defined Benefit Pension Plans $ — $ 10,200 $ 10,200 Non-pension Defined Benefit Postretirement Healthcare Plans $ 939 $ 2,816 $ 4,026 Supplemental Non-qualified Defined Benefit and Defined Contribution Plans $ 372 $ 1,115 $ 1,544

Management Statement (continu36

Management Statement (continued) Revision of Prior Period Financial Statements (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Liabilities, Noncurrent	$ 971,116	$ 818,174	$ 973,148
Income Statement [Abstract]
Depreciation, depletion and amortization	39,002	35,249
Impairment of long-lived assets	22,036	0
Total operating expenses	371,487	369,737
Operating income (loss)	70,500	90,432
Income (loss) before earnings (loss) of unconsolidated subsidiaries and income taxes	51,859	74,319
Income tax benefit (expense)	(17,712)	(25,673)
Net income (loss) available for common stock	$ 33,850	$ 48,645
Earnings (loss) per share of common stock:
Earnings (loss) per share, Basic	$ 0.76	$ 1.10
Earnings (loss) per share, Diluted	$ 0.76	$ 1.09
Statement of Comprehensive Income [Abstract]
Net income (loss) available for common stock	$ 33,850	$ 48,645
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	34,840	47,478
Statement of Financial Position [Abstract]
Accumulated depreciation and depletion	(1,407,214)	(1,334,806)	(1,357,929)
Total property, plant and equipment, net	3,244,844	2,983,388	3,205,471
Total Assets (net of inter-company eliminations)	4,264,471	3,928,556	4,245,902
Deferred income tax liability, non-current	503,117	454,169	511,952
Retained earnings	592,951	547,242	577,249
Total stockholders’ equity	1,371,583	1,313,698	1,353,884
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	4,264,471	3,928,556	$ 4,245,902
Statement of Cash Flows [Abstract]
Net income (loss) available for common stock	33,850	48,645
Depreciation, depletion and amortization	39,002	35,249
Deferred income taxes	14,640	26,260
Net Cash Provided by (Used in) Operating Activities	151,487	98,098
As Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Liabilities, Noncurrent	990,289	830,861
Income Statement [Abstract]
Depreciation, depletion and amortization	39,586	36,083
Impairment of long-lived assets	0
Total operating expenses	350,035	370,571
Operating income (loss)	91,952	89,598
Income (loss) before earnings (loss) of unconsolidated subsidiaries and income taxes	73,311	73,485
Income tax benefit (expense)	25,120	25,366
Net income (loss) available for common stock	$ 47,894	$ 48,118
Earnings (loss) per share of common stock:
Earnings (loss) per share, Basic	$ 1.08	$ 1.09
Earnings (loss) per share, Diluted	$ 1.07	$ 1.08
Statement of Comprehensive Income [Abstract]
Net income (loss) available for common stock	$ 47,894	$ 48,118
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	48,884	46,951
Statement of Financial Position [Abstract]
Accumulated depreciation and depletion	(1,351,857)	(1,298,398)
Total property, plant and equipment, net	3,300,201	3,019,796
Total Assets (net of inter-company eliminations)	4,319,828	3,964,964
Deferred income tax liability, non-current	522,290	466,856
Retained earnings	629,135	570,963
Total stockholders’ equity	1,407,767	1,337,419
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	4,319,828	3,964,964
Statement of Cash Flows [Abstract]
Net income (loss) available for common stock	47,894	48,118
Depreciation, depletion and amortization	39,586	36,083
Deferred income taxes	22,048	25,953
Net Cash Provided by (Used in) Operating Activities	151,487	98,098
Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Liabilities, Noncurrent	(19,173)	(12,687)
Income Statement [Abstract]
Depreciation, depletion and amortization	(584)	(834)
Impairment of long-lived assets	22,036
Total operating expenses	21,452	(834)
Operating income (loss)	(21,452)	834
Income (loss) before earnings (loss) of unconsolidated subsidiaries and income taxes	(21,452)	834
Income tax benefit (expense)	7,408	(307)
Net income (loss) available for common stock	$ (14,044)	$ 527
Earnings (loss) per share of common stock:
Earnings (loss) per share, Basic	$ (0.32)	$ 0.01
Earnings (loss) per share, Diluted	$ (0.31)	$ 0.01
Statement of Comprehensive Income [Abstract]
Net income (loss) available for common stock	$ (14,044)	$ 527
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	(14,044)	527
Statement of Financial Position [Abstract]
Accumulated depreciation and depletion	(55,357)	(36,408)
Total property, plant and equipment, net	(55,357)	(36,408)
Total Assets (net of inter-company eliminations)	(55,357)	(36,408)
Deferred income tax liability, non-current	(19,173)	(12,687)
Retained earnings	(36,184)	(23,721)
Total stockholders’ equity	(36,184)	(23,721)
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	(55,357)	(36,408)
Statement of Cash Flows [Abstract]
Net income (loss) available for common stock	(14,044)	527
Depreciation, depletion and amortization	(584)	(834)
Deferred income taxes	(7,408)	307
Net Cash Provided by (Used in) Operating Activities	$ 0	$ 0

Business Segment Information_ I

Business Segment Information: Information Relating to Segment Statement of Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Segment Reporting Information
Revenue	$ 441,987		$ 460,169
Net Income (Loss)	33,850		48,645
Inter-company eliminations [Member]
Segment Reporting Information
Revenue	(31,937)		(33,966)
Net Income (Loss)	0		0
Corporate activities[Member]
Segment Reporting Information
Revenue	0		0
Net Income (Loss)	669		330
Consolidation, Eliminations [Member]
Segment Reporting Information
Revenue	0		0
Electric Utilities [Member]
Segment Reporting Information
Revenue	182,974		178,095
Net Income (Loss)	18,929		14,575
Electric Utilities [Member] | Inter-company eliminations [Member]
Segment Reporting Information
Revenue	3,424		4,007
Gas Utilities [Member]
Segment Reporting Information
Revenue	237,651		259,337
Net Income (Loss)	22,212		24,698
Gas Utilities [Member] | Inter-company eliminations [Member]
Segment Reporting Information
Revenue	0		0
Power Generation [Member]
Segment Reporting Information
Revenue	1,953		1,269
Net Income (Loss)	8,145		8,073
Power Generation [Member] | Inter-company eliminations [Member]
Segment Reporting Information
Revenue	20,721		21,079
Coal Mining [Member]
Segment Reporting Information
Revenue	8,142		6,618
Net Income (Loss)	3,010		2,464
Coal Mining [Member] | Inter-company eliminations [Member]
Segment Reporting Information
Revenue	7,792		8,880
Oil and Gas [Member]
Segment Reporting Information
Revenue	11,267		14,850
Net Income (Loss)	(19,115)	[1]	(1,495)
Oil and Gas [Member] | Inter-company eliminations [Member]
Segment Reporting Information
Revenue	$ 0		$ 0
[1]	(a) Net income (loss) includes ceiling test impairment (see Note 15)

Business Segment Information_ S

Business Segment Information: Segment and Corporate Assets (Details) - USD ($) $ in Thousands		Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Segment Reporting, Asset Reconciling Item [Line Items]
Assets		$ 4,264,471	$ 4,245,902	$ 3,928,556
Corporate activities[Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets		105,602	106,605	89,439
Electric Utilities [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	[1]	2,817,423	2,748,680	2,572,616
Gas Utilities [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets		839,802	906,922	842,660
Power Generation [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	[1]	75,945	76,945	90,643
Coal Mining [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets		77,399	74,407	74,523
Oil and Gas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets		$ 348,300	$ 332,343	$ 258,675
[1]	The PPA under which Black Hills Colorado IPP provides generation to support Colorado Electric customers from the Pueblo Airport Generation Station is accounted for as a capital lease. As such, assets owned by our Power Generation segment are recorded at Colorado Electric under accounting for a capital lease.

Accounts Receivable_ Accounts39

Accounts Receivable: Accounts Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Accounts Receivable [Line Items]
Allowance for Doubtful Accounts	$ (2,435)	$ (1,516)	$ (1,517)
Accounts receivable, net	178,421	189,992	203,625
Corporate[Member]
Accounts Receivable [Line Items]
Allowance for Doubtful Accounts	0	0	0
Accounts receivable, net	981	2,555	2,697
Electric Utilities [Member]
Accounts Receivable [Line Items]
Allowance for Doubtful Accounts	(834)	(722)	(690)
Accounts receivable, net	77,568	85,466	73,106
Gas Utilities [Member]
Accounts Receivable [Line Items]
Allowance for Doubtful Accounts	(1,588)	(781)	(814)
Accounts receivable, net	90,449	92,159	112,959
Power Generation [Member]
Accounts Receivable [Line Items]
Allowance for Doubtful Accounts	0	0	0
Accounts receivable, net	1,152	1,369	1,340
Coal Mining [Member]
Accounts Receivable [Line Items]
Allowance for Doubtful Accounts	0	0	0
Accounts receivable, net	3,638	3,151	2,616
Oil and Gas [Member]
Accounts Receivable [Line Items]
Allowance for Doubtful Accounts	(13)	(13)	(13)
Accounts receivable, net	4,633	5,292	10,907
Billed Revenues [Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	127,531	119,488	149,288
Billed Revenues [Member] | Corporate[Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	981	2,555	2,697
Billed Revenues [Member] | Electric Utilities [Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	53,862	59,714	53,733
Billed Revenues [Member] | Gas Utilities [Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	63,252	47,394	77,982
Billed Revenues [Member] | Power Generation [Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	1,152	1,369	1,340
Billed Revenues [Member] | Coal Mining [Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	3,638	3,151	2,616
Billed Revenues [Member] | Oil and Gas [Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	4,646	5,305	10,920
Unbilled Revenues [Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	53,325	72,020	55,854
Unbilled Revenues [Member] | Corporate[Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	0	0	0
Unbilled Revenues [Member] | Electric Utilities [Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	24,540	26,474	20,063
Unbilled Revenues [Member] | Gas Utilities [Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	28,785	45,546	35,791
Unbilled Revenues [Member] | Power Generation [Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	0	0	0
Unbilled Revenues [Member] | Coal Mining [Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	0	0	0
Unbilled Revenues [Member] | Oil and Gas [Member]
Accounts Receivable [Line Items]
Accounts Receivable, Trade	$ 0	$ 0	$ 0

Regulatory Accounting_ Regula40

Regulatory Accounting: Regulatory Assets and Liabilities (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Schedule Of Regulatory Assets And Liabilities [Line Items]
Regulatory Assets		$ 235,477	$ 257,839	$ 201,119
Regulatory Liabilities		$ 166,539	148,831	117,376
Deferred energy and gas costs
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		1 year
Regulatory Liabilities	[1],[2]	$ 18,094	6,496	6,485
Employee benefit plans
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		12 years
Regulatory Liabilities	[3],[4]	$ 53,151	53,139	34,355
Cost of removal
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		44 years
Regulatory Liabilities	[2]	$ 81,449	78,249	67,640
Other regulatory liabilities
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		25 years
Regulatory Liabilities	[3]	$ 13,845	10,947	8,896
Deferred energy and gas costs
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		1 year
Regulatory Assets	[1],[2]	$ 30,833	23,820	23,935
Deferred gas cost adjustments
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		2 years
Regulatory Assets	[1],[2]	$ 6,138	37,471	38,505
Gas price derivatives
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		7 years
Regulatory Assets	[2]	$ 21,606	18,740	4,420
AFUDC
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		45 years
Regulatory Assets	[5]	$ 12,114	12,358	12,349
Employee benefit plans
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		12 years
Regulatory Assets	[3],[4]	$ 97,700	97,126	65,833
Environmental
Schedule Of Regulatory Assets And Liabilities [Line Items]
Regulatory Assets	[2]	$ 1,240	1,314	1,317
Asset retirement obligations
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		44 years
Regulatory Assets	[2]	$ 3,237	3,287	3,271
Bond issue cost
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		23 years
Regulatory Assets	[2]	$ 3,240	3,276	3,383
Renewable energy standard adjustment
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		5 years
Regulatory Assets	[2]	$ 5,590	9,622	16,088
Flow through accounting
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		35 years
Regulatory Assets	[3]	$ 26,835	25,887	21,837
Decommissioning costs
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		10 years
Regulatory Assets		$ 13,702	12,484	0
Other regulatory assets
Schedule Of Regulatory Assets And Liabilities [Line Items]
Maximum Amortization Period		15 years
Regulatory Assets	[2]	$ 13,242	$ 12,454	$ 10,181
[1]	Our deferred energy, fuel cost, and gas cost adjustments represent the cost of electricity and gas delivered to our electric and gas utility customers that is either higher or lower than current rates and will be recovered or refunded in future rates. Fluctuations in deferred gas cost adjustments compared to the same period in the prior year are primarily due to higher natural gas prices driven by demand and market conditions from the peak winter heating season in the first part of 2014. Our electric and gas utilities file periodic quarterly, semi-annual, and/or annual filings to recover these costs based on the respective cost mechanisms approved by their applicable state utility commissions.
[2]	Recovery of costs, but we are not allowed a rate of return.
[3]	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.
[4]	Increase compared to March 31, 2014 is due to a decrease in the discount rate and a change in the mortality tables used in employee benefit plan estimates.
[5]	In addition to recovery of costs, we are allowed a rate of return.

Materials, Supplies and Fuel_41

Materials, Supplies and Fuel: Materials, Supplies and Fuel (Details) - USD ($) $ in Thousands	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Inventory, Net [Abstract]
Materials and supplies	$ 52,429	$ 49,555	$ 50,727
Fuel - Electric Utilities	6,780	6,637	7,218
Natural gas in storage held for distribution	7,417	34,999	8,242
Total materials, supplies and fuel	$ 66,626	$ 91,191	$ 66,187

Earnings Per Share_ Earnings 42

Earnings Per Share: Earnings Per Share (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Net income (loss) available for common stock	$ 33,850	$ 48,645
Weighted average shares - basic	44,541	44,330
Dilutive effect of:
Equity compensation	119	224
Weighted average shares - diluted	44,660	44,554

Earnings Per Share_ Anti-diluti

Earnings Per Share: Anti-dilutive shares (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares	107	46
Stock Compensation Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares	107	46

Notes Payable and Long-term D44

Notes Payable and Long-term Debt: Notes Payable (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Mar. 31, 2014USD ($)
Revolving Credit Facility [Line Items]
Balance Outstanding	$ 102,600	$ 75,000	$ 100,000
Revolving Credit Facility [Member]
Revolving Credit Facility [Line Items]
Balance Outstanding	102,600	75,000	100,000
Letters of Credit	22,300	$ 35,000	$ 27,700
Current Borrowing Capacity	$ 500,000
Expiration Date	May 29, 2019
Maximum Borrowing Capacity	$ 750,000
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.175%
Debt Covenants Disclosure [Abstract]
Covenant Requirement - Recourse Leverage Ratio, Actual	55.00%
Covenant Requirement - Recourse Leverage Ratio, Maximum	0.65
Revolving Credit Facility [Member] | Base Rate [Member]
Revolving Credit Facility [Line Items]
Interest Rate at Period End	0.125%
Revolving Credit Facility [Member] | Eurodollar [Member]
Revolving Credit Facility [Line Items]
Interest Rate at Period End	1.125%
Revolving Credit Facility [Member] | Letter of Credit [Member]
Revolving Credit Facility [Line Items]
Interest Rate at Period End	1.125%

Notes Payable and Long-term D45

Notes Payable and Long-term Debt: Refinancing of Debt (Details) - Black Hills Corporation [Member] - USD ($) $ in Millions	Apr. 13, 2015	Mar. 31, 2015
Corporate Term Loan Due June 2015 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 275
Corporate Term Loan Due April 2017 [Member] | Subsequent Event [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Basis Spread on Variable Rate	0.90%
Corporate Debt Securities [Member] | Corporate Term Loan Due April 2017 [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Additional debt used for general corporate purposes	$ 25
Corporate Debt Securities [Member] | Corporate Term Loan Due April 2017 [Member] | Subsequent Event [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 300
Debt Instrument, Maturity Date	Apr. 12, 2017

Risk Management Activities_ R46

Risk Management Activities: Risk Management Activities (Details) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2015USD ($)MMBTUbbl	Mar. 31, 2014USD ($)MMBTUbbl	Dec. 31, 2014USD ($)MMBTUbbl
Derivative [Line Items]
Derivative assets, current		$ 0	$ 1,846	$ 0
Derivative liabilities, current		3,342	3,498	3,340
Derivative liabilities, non-current		2,143	4,805	2,680
Oil and Gas [Member]
Derivative [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months		9,900
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative liabilities, current		3,342	3,498	3,340
Derivative liabilities, non-current		2,143	4,805	2,680
Notional Amount	[1]	$ 75,000	$ 75,000	$ 75,000
Weighted average fixed interest rate		4.97%	4.97%	4.97%
Maximum Term		1 year 9 months	2 years 9 months	2 years
Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net		$ (3,300)
Crude Oil [Member] | Swaps and Options [Member] | Oil and Gas [Member]
Derivative [Line Items]
Notional amount - commodities | bbl	[2]	305,000	442,500	334,500
Maximum Term Hedged in Cash Flow Hedge	[3]	1 month	1 month	1 month
Derivative assets, current		$ 0	$ 0	$ 0
Derivative assets, non-current		0	0	0
Derivative liabilities, current		0	0	0
Derivative liabilities, non-current		$ 0	$ 0	$ 0
Natural Gas [Member] | Swap [Member] | Oil and Gas [Member]
Derivative [Line Items]
Notional amount - commodities | MMBTU	[2]	5,367,500	8,296,250	6,582,500
Maximum Term Hedged in Cash Flow Hedge	[3]	1 month	1 month	1 month
Derivative assets, current		$ 0	$ 0	$ 0
Derivative assets, non-current		0	0	0
Derivative liabilities, current		0	0	0
Derivative liabilities, non-current		0	0	0
Utilities Group [Member] | Natural Gas, Distribution [Member]
Derivative [Line Items]
Derivative assets, current		0	1,846	0
Derivative assets, non-current		0	0	0
Derivative liabilities, non-current		0	0	0
Net Unrealized (Gain) Loss Included in Regulatory assets or Regulatory liabilities		$ 21,606	$ 4,420	$ 18,740
Utilities Group [Member] | Natural Gas, Distribution [Member] | Future [Member] | Purchase Contract [Member]
Derivative [Line Items]
Notional amount - commodities | MMBTU		17,280,000	16,140,000	19,370,000
Maximum Term	[4]	69 months	80 months	72 months
Utilities Group [Member] | Natural Gas, Distribution [Member] | Commodity Option [Member] | Purchase Contract [Member]
Derivative [Line Items]
Notional amount - commodities | MMBTU		1,320,000	1,320,000	4,020,000
Maximum Term	[4]	12 months	12 months	8 months
Utilities Group [Member] | Natural Gas, Distribution [Member] | Basis Swap [Member] | Purchase Contract [Member]
Derivative [Line Items]
Notional amount - commodities | MMBTU		15,735,000	14,575,000	12,005,000
Maximum Term	[4]	57 months	69 months	60 months
[1]	These swaps are designated to borrowings on our Revolving Credit Facility, and are priced using three-month LIBOR, matching the floating portion of the related borrowings.
[2]	Crude oil in Bbls, natural gas in MMBtus.
[3]	Refers to the tenor of the derivative instrument. Assets and liabilities are classified as current/non-current based on the production month hedged and the corresponding settlement of the derivative instrument.
[4]	Term reflects the maximum forward period hedged.

Risk Management Activities_ Hed

Risk Management Activities: Hedging Activities (Details) - Cash Flow Hedging [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in AOCI Derivative (Effective Portion)	$ 2,878	$ (3,564)
Amount of Reclassified Gain/(Loss) from AOCI into Income (Effective Portion)	(2,495)	(1,205)
Amount of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion)	0	0
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in AOCI Derivative (Effective Portion)	(886)	(91)
Amount of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion)	0	0
Interest Rate Swap [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Reclassified Gain/(Loss) from AOCI into Income (Effective Portion)	1,437	(894)
Commodity Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain/(Loss) Recognized in AOCI Derivative (Effective Portion)	3,764	(3,473)
Commodity Contract [Member] | Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Reclassified Gain/(Loss) from AOCI into Income (Effective Portion)	(3,932)	(311)
Amount of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion)	$ 0	$ 0

Fair Value Measurements_ Fair48

Fair Value Measurements: Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Fair Value, Transfers Between Level 1 and Level 2, Description and Policy [Abstract]
Assets-Transfers out of level 1 to 2	$ 0	$ 0	$ 0
Assets -Transfers out of level 2 to 1	0	0	0
Liabilities -Transfers out of level 1 to 2	0	0	0
Liabilities -Transfers out of level 2 to 1	0	0	0
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	(15,806)	(17,546)	(1,877)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	(22,260)	(19,776)	(11,016)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Total	0	0	0
Derivative Liabilities, Total	0	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Total	15,806	17,546	3,723
Derivative Liabilities, Total	27,745	25,796	19,319
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Total	0	0	0
Derivative Liabilities, Total	0	0	0
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liabilities, Fair Value Disclosure	5,485	6,020	8,303
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	0	0	0
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liabilities, Fair Value Disclosure	0	0	0
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liabilities, Fair Value Disclosure	5,485	6,020	8,303
Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liabilities, Fair Value Disclosure	0	0	0
Crude Oil [Member] | Commodity Option [Member] | Fair Value, Measurements, Recurring [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	0	0	0
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	0	0	0
Crude Oil [Member] | Commodity Option [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Crude Oil [Member] | Commodity Option [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Crude Oil [Member] | Commodity Option [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Crude Oil [Member] | Basis Swap [Member] | Fair Value, Measurements, Recurring [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	(8,096)	(8,599)	(7)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	(2)	0	(1,983)
Crude Oil [Member] | Basis Swap [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Crude Oil [Member] | Basis Swap [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	8,096	8,599	7
Derivative Liabilities, Fair Value Disclosure	2	0	1,983
Crude Oil [Member] | Basis Swap [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Natural Gas [Member] | Commodity Option [Member] | Fair Value, Measurements, Recurring [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	0	0	0
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	0	0	0
Natural Gas [Member] | Commodity Option [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Natural Gas [Member] | Commodity Option [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Natural Gas [Member] | Commodity Option [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Natural Gas [Member] | Basis Swap [Member] | Fair Value, Measurements, Recurring [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	(6,526)	(6,558)	(490)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	(256)	(473)	(2,114)
Natural Gas [Member] | Basis Swap [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Natural Gas [Member] | Basis Swap [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	6,526	6,558	490
Derivative Liabilities, Fair Value Disclosure	256	473	2,114
Natural Gas [Member] | Basis Swap [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Natural Gas, Distribution [Member] | Fair Value, Measurements, Recurring [Member] | Utilities Group [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset	(1,184)	(2,389)	(1,380)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	(22,002)	(19,303)	(6,919)
Natural Gas, Distribution [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Utilities Group [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Natural Gas, Distribution [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Utilities Group [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	1,184	2,389	3,226
Derivative Liabilities, Fair Value Disclosure	22,002	19,303	6,919
Natural Gas, Distribution [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Utilities Group [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Total	0	0	1,846
Derivative Liabilities, Total	5,485	6,020	8,303
Estimate of Fair Value Measurement [Member] | Crude Oil [Member] | Commodity Option [Member] | Fair Value, Measurements, Recurring [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Estimate of Fair Value Measurement [Member] | Crude Oil [Member] | Basis Swap [Member] | Fair Value, Measurements, Recurring [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Estimate of Fair Value Measurement [Member] | Natural Gas [Member] | Commodity Option [Member] | Fair Value, Measurements, Recurring [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Estimate of Fair Value Measurement [Member] | Natural Gas [Member] | Basis Swap [Member] | Fair Value, Measurements, Recurring [Member] | Oil and Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	0
Derivative Liabilities, Fair Value Disclosure	0	0	0
Estimate of Fair Value Measurement [Member] | Natural Gas, Distribution [Member] | Fair Value, Measurements, Recurring [Member] | Utilities Group [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Commodity Derivatives	0	0	1,846
Derivative Liabilities, Fair Value Disclosure	$ 0	$ 0	$ 0

Fair Value Measurements_ Balanc

Fair Value Measurements: Balance Sheet Location (Details) - USD ($) $ in Thousands	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Designated as Hedging Instrument [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Asset, Fair Value, Net	$ 14,622	$ 15,157	$ 496
Derivative Liability, Fair Value, Net	5,743	6,493	12,400
Not Designated as Hedging Instrument [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Asset, Fair Value, Net	0	0	1,846
Derivative Liability, Fair Value, Net	20,818	16,914	5,539
Commodity Contract [Member] | Designated as Hedging Instrument [Member] | Derivative Assets, Current [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	9,989	10,391	30
Derivative Asset, Fair Value, Gross Liability	0	0	0
Commodity Contract [Member] | Designated as Hedging Instrument [Member] | Derivative Assets, Non-current [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	4,633	4,766	466
Derivative Asset, Fair Value, Gross Liability	0	0	0
Commodity Contract [Member] | Designated as Hedging Instrument [Member] | Derivative Liabilities, Current [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Asset	0	0	0
Derivative Liability, Fair Value, Gross Liability	126	185	3,187
Commodity Contract [Member] | Designated as Hedging Instrument [Member] | Derivative Liabilities, Non-current [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Asset	0	0	0
Derivative Liability, Fair Value, Gross Liability	132	288	910
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Derivative Assets, Current [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0	1,846
Derivative Asset, Fair Value, Gross Liability	0	0	0
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Derivative Assets, Non-current [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0	0
Derivative Asset, Fair Value, Gross Liability	0	0	0
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Derivative Liabilities, Current [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Asset	0	0	0
Derivative Liability, Fair Value, Gross Liability	7,530	8,032	0
Commodity Contract [Member] | Not Designated as Hedging Instrument [Member] | Derivative Liabilities, Non-current [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Asset	0	0	0
Derivative Liability, Fair Value, Gross Liability	13,288	8,882	5,539
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Derivative Liabilities, Current [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Asset	0	0	0
Derivative Liability, Fair Value, Gross Liability	3,342	3,340	3,498
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Derivative Liabilities, Non-current [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Asset	0	0	0
Derivative Liability, Fair Value, Gross Liability	$ 2,143	$ 2,680	4,805
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member] | Derivative Liabilities, Current [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Asset			0
Derivative Liability, Fair Value, Gross Liability			0
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member] | Derivative Liabilities, Non-current [Member]
Derivatives, Carrying Amount and Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Asset			0
Derivative Liability, Fair Value, Gross Liability			$ 0

Fair Value of Financial Instr50

Fair Value of Financial Instruments: Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		$ 63,385	$ 21,218	$ 17,641	$ 7,841
Restricted cash and equivalents		2,191	2,056	2
Notes payable		102,600	75,000	100,000
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		63,385	21,218	17,641
Restricted cash and equivalents		2,191	2,056	2
Notes payable		102,600	75,000	100,000
Long-term debt, including current maturities		1,542,658	1,542,589	1,396,949
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, Fair Value	[1]	63,385	21,218	17,641
Restricted Cash Fair Value Disclosure	[1]	2,191	2,056	2
Notes payable, Fair Value	[1]	102,600	75,000	100,000
Long-term debt, including current maturities, Fair Value	[2]	$ 1,767,113	$ 1,734,555	$ 1,541,727
[1]	Carrying value approximates fair value due to either the 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 based on observable inputs available either directly or indirectly for similar liabilities in active markets and therefore is classified in Level 2 in the fair value hierarchy.

Other Comprehensive Income (L51

Other Comprehensive Income (Loss): Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ 19,910	$ 17,860
Revenue	441,987	460,169
Utilities - Operating and maintenance	71,084	71,227
Non-regulated energy operations and maintenance	22,050	22,332
Income (loss) before earnings (loss) of unconsolidated subsidiaries and income taxes	51,859	74,319
Income tax benefit (expense)	(17,712)	(25,673)
Cash Flow Hedging [Member] | Reclassification Out Of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before earnings (loss) of unconsolidated subsidiaries and income taxes	(2,495)	1,205
Income tax benefit (expense)	1,254	(425)
Net income (loss) available for common stock	(1,241)	780
Cash Flow Hedging [Member] | Reclassification Out Of Accumulated Other Comprehensive Income [Member] | Interest Rate Contract [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense	1,437	894
Cash Flow Hedging [Member] | Reclassification Out Of Accumulated Other Comprehensive Income [Member] | Commodity Contract [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Revenue	(3,932)	311
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Cost (Credit) [Member] | Reclassification Out Of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Utilities - Operating and maintenance	(27)	(25)
Non-regulated energy operations and maintenance	(28)	12
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) [Member] | Reclassification Out Of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Utilities - Operating and maintenance	454	157
Non-regulated energy operations and maintenance	251	85
Accumulated Defined Benefit Plans Adjustment [Member] | Reclassification Out Of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before earnings (loss) of unconsolidated subsidiaries and income taxes	650	229
Income tax benefit (expense)	(228)	(81)
Net income (loss) available for common stock	$ 422	$ 148

Other Comprehensive Income (L52

Other Comprehensive Income (Loss): Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start	$ (15,044)	$ (17,422)
Other comprehensive income (loss), net of tax	990	(1,167)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End	(14,054)	(18,589)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start	5,093	(7,133)
Other comprehensive income (loss), net of tax	595	(1,478)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End	5,688	(8,611)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start	(20,137)	(10,289)
Other comprehensive income (loss), net of tax	395	311
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End	$ (19,742)	$ (9,978)

Supplemental Disclosure of Ca53

Supplemental Disclosure of Cash Flow Information: Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Non-cash Investing and Financing Activities from Continuing Operations [Abstract]
Property, plant and equipment acquired with accrued liabilities	$ 33,534	$ 40,939
Increase (decrease) in capitalized assets associated with asset retirement obligations	0	(2,785)
Supplemental Cash Flow Elements [Abstract]
Interest (net of amounts capitalized)	(10,909)	(11,452)
Income taxes, net	$ (2)	$ 4

Employee Benefit Plans_ Emplo54

Employee Benefit Plans: Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Defined Benefit Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 1,494	$ 1,362
Interest cost	3,880	3,963
Expected return on plan assets	(4,867)	(4,516)
Prior service cost (benefit)	15	16
Net loss (gain)	2,759	1,201
Net periodic benefit cost	3,281	2,026
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions by Employer	0
Estimated Future Employer Contributions in Current Fiscal Year	10,200
Estimated Future Employer Contributions in Next Fiscal Year	10,200
Defined Benefit Postretirement Healthcare Plans
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	464	425
Interest cost	450	479
Expected return on plan assets	(33)	(21)
Prior service cost (benefit)	(107)	(107)
Net loss (gain)	102	40
Net periodic benefit cost	876	816
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions by Employer	939
Estimated Future Employer Contributions in Current Fiscal Year	2,816
Estimated Future Employer Contributions in Next Fiscal Year	4,026
Supplemental Non-qualified Defined Benefit and Defined Contribution Plans
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	491	374
Interest cost	364	362
Prior service cost (benefit)	1	1
Net loss (gain)	270	124
Net periodic benefit cost	1,126	$ 861
Pension and Other Postretirement Benefit Contributions [Abstract]
Contributions by Employer	372
Estimated Future Employer Contributions in Current Fiscal Year	1,115
Estimated Future Employer Contributions in Next Fiscal Year	$ 1,544

Commitments and Contingencies_

Commitments and Contingencies: Commitments and Contingencies - Oil Creek Fire (Details) - Pending Litigation [Member] - Oil Creek Fire [Member] - Loss from Catastrophes [Member] $ in Millions	3 Months Ended
	Mar. 31, 2015USD ($)
Minimum [Member]
Loss Contingencies [Line Items]
Insurance Coverage Deductible Per Occurrence	$ 1
Maximum [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value	$ 55

Commitments and Contingencies56

Commitments and Contingencies: Commitments and Contingencies - Dividend Restrictions (Details) $ in Millions	Mar. 31, 2015USD ($)
Utilities Group [Member]
Related Party Transaction [Line Items]
Restricted Net Assets for Subsidiaries	$ 338