$BKH
BLACK HILLS CORP /SD/ Stock $bkh

$bkh Overview Financials Valuation SEC Filings Company Website

2014 Q4 Form 10-K Financial Statement

#000113046416000176 Filed on February 25, 2016

Income Statement

Concept	2014 Q4	2014 Q3	2014 Q2
Revenue	$378.1M	$272.1M	$283.2M
YoY Change	6.37%	4.69%	1.22%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$36.90M	$36.63M	$35.88M
YoY Change	18.27%	1.36%	2.06%
% of Gross Profit
Operating Expenses	$304.8M	$216.8M	$235.8M
YoY Change	8.66%	6.12%	2.18%
Operating Profit	$70.79M	$55.24M	$47.41M
YoY Change	-0.45%	-0.59%	-3.31%
Interest Expense	-$18.50M	-$16.80M	-$16.80M
YoY Change	-55.31%	-13.85%	394.12%
% of Operating Profit	-26.14%	-30.41%	-35.43%
Other Income/Expense, Net	$600.0K	$261.0K	$409.0K
YoY Change	50.0%	-17.92%	-13.53%
Pretax Income	$55.40M	$39.00M	$31.31M
YoY Change	62.94%	6.98%	-32.14%
Income Tax	$19.30M	$11.64M	$10.96M
% Of Pretax Income	34.84%	29.84%	35.01%
Net Earnings	$36.10M	$27.40M	$20.30M
YoY Change	75.24%	18.61%	-33.48%
Net Earnings / Revenue	9.55%	10.07%	7.17%
Basic Earnings Per Share	$0.78	$0.61	$0.46
Diluted Earnings Per Share	$0.77	$0.61	$0.46
COMMON SHARES
Basic Shares Outstanding	44.66M shares	44.42M shares	44.40M shares
Diluted Shares Outstanding		44.61M shares	44.59M shares

Balance Sheet

Concept	2014 Q4	2014 Q3	2014 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments	$21.20M	$11.90M	$14.70M
YoY Change	171.79%	-12.5%	-51.96%
Cash & Equivalents	$21.22M	$11.94M	$14.70M
Short-Term Investments
Other Short-Term Assets	$24.84M	$26.50M	$21.66M
YoY Change	-4.0%	-2.12%	-21.51%
Inventory	$91.19M	$105.7M	$81.16M
Prepaid Expenses
Receivables	$190.0M	$123.4M	$135.1M
Other Receivables	$2.000M	$1.300M	$1.100M
Total Short-Term Assets	$454.0M	$374.0M	$344.1M
YoY Change	31.49%	13.7%	1.77%
LONG-TERM ASSETS
Property, Plant & Equipment	$3.205B	$3.120B	$3.047B
YoY Change	7.2%	7.84%	7.6%
Goodwill	$353.4M	$353.4M	$353.4M
YoY Change	0.0%	0.0%	0.0%
Intangibles	$3.176M	$3.231M	$3.286M
YoY Change	-6.51%	-6.43%	-6.33%
Long-Term Investments	$17.30M	$17.10M	$17.10M
YoY Change	3.59%	3.01%	3.01%
Other Assets	$29.09M	$29.93M	$31.81M
YoY Change	4.23%	35.33%	41.99%
Total Long-Term Assets	$569.1M	$527.0M	$526.7M
YoY Change	8.84%	-6.25%	-5.94%
TOTAL ASSETS
Total Short-Term Assets	$454.0M	$374.0M	$344.1M
Total Long-Term Assets	$569.1M	$527.0M	$526.7M
Total Assets	$4.246B	$4.039B	$3.935B
YoY Change	9.57%	6.24%	5.03%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$124.1M	$100.4M	$100.1M
YoY Change	-4.81%	30.32%	13.66%
Accrued Expenses	$170.1M	$163.4M	$141.2M
YoY Change	12.45%	6.84%	3.94%
Deferred Revenue
YoY Change
Short-Term Debt	$75.00M	$184.0M	$132.7M
YoY Change	-9.09%	33.04%	32.7%
Long-Term Debt Due	$275.0M	$275.0M	$275.0M
YoY Change		7.55%	7.63%
Total Short-Term Liabilities	$651.3M	$727.0M	$653.3M
YoY Change	72.12%	3.18%	-2.38%
LONG-TERM LIABILITIES
Long-Term Debt	$1.268B	$1.108B	$1.122B
YoY Change	-9.26%	15.85%	17.05%
Other Long-Term Liabilities	$154.4M	$144.1M	$137.8M
YoY Change	15.85%	8.06%	6.17%
Total Long-Term Liabilities	$973.1M	$869.2M	$841.6M
YoY Change	22.86%	2.3%	0.66%
TOTAL LIABILITIES
Total Short-Term Liabilities	$651.3M	$727.0M	$653.3M
Total Long-Term Liabilities	$973.1M	$869.2M	$841.6M
Total Liabilities	$1.624B	$1.596B	$1.495B
YoY Change	38.78%	2.7%	-0.69%
SHAREHOLDERS EQUITY
Retained Earnings	$577.2M	$560.1M	$550.2M
YoY Change	6.85%	3.91%	3.26%
Common Stock	$44.71M	$791.3M	$789.2M
YoY Change	-94.32%	0.83%	0.89%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$1.875M	$1.841M	$1.801M
YoY Change	-4.73%	2.22%	13.48%
Treasury Stock Shares	42.23K shares	41.55K shares	40.95K shares
Shareholders Equity	$1.354B	$1.357B	$1.318B
YoY Change
Total Liabilities & Shareholders Equity	$4.246B	$4.039B	$3.935B
YoY Change	9.57%	6.24%	5.03%

Cashflow Statement

Concept	2014 Q4	2014 Q3	2014 Q2
OPERATING ACTIVITIES
Net Income	$36.10M	$27.40M	$20.30M
YoY Change	75.24%	18.61%	-33.48%
Depreciation, Depletion And Amortization	$36.90M	$36.63M	$35.88M
YoY Change	18.27%	1.36%	2.06%
Cash From Operating Activities	$76.10M	$65.40M	$75.70M
YoY Change	4.53%	20.22%	-14.17%
INVESTING ACTIVITIES
Capital Expenditures	-$108.2M	-$113.0M	-$93.70M
YoY Change	-6.08%	22.43%	12.48%
Acquisitions
YoY Change
Other Investing Activities	-$22.70M	$23.00M	$200.0K
YoY Change	-940.74%	2775.0%	-80.0%
Cash From Investing Activities	-$130.8M	-$90.00M	-$93.50M
YoY Change	16.06%	-1.53%	13.61%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	55.80M	22.00M	14.80M
YoY Change	64.12%	10.0%	19.35%
NET CHANGE
Cash From Operating Activities	76.10M	65.40M	75.70M
Cash From Investing Activities	-130.8M	-90.00M	-93.50M
Cash From Financing Activities	55.80M	22.00M	14.80M
Net Change In Cash	1.100M	-2.600M	-3.000M
YoY Change	-118.64%	-84.71%	-116.39%
FREE CASH FLOW
Cash From Operating Activities	$76.10M	$65.40M	$75.70M
Capital Expenditures	-$108.2M	-$113.0M	-$93.70M
Free Cash Flow	$184.3M	$178.4M	$169.4M
YoY Change	-1.97%	21.61%	-1.22%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2013	bkh	Average Crude Oil Price Per Barrel Nymex AverageCrudeOilPricePerBarrelNYMEX	96.94
CY2014	bkh	Average Crude Oil Price Per Barrel Nymex AverageCrudeOilPricePerBarrelNYMEX	94.99
CY2015	bkh	Average Crude Oil Price Per Barrel Nymex AverageCrudeOilPricePerBarrelNYMEX	50.28
CY2013	bkh	Average Crude Oil Price Per Barrel Wellhead AverageCrudeOilPricePerBarrelWellhead	89.79
CY2014	bkh	Average Crude Oil Price Per Barrel Wellhead AverageCrudeOilPricePerBarrelWellhead	85.80
CY2015	bkh	Average Crude Oil Price Per Barrel Wellhead AverageCrudeOilPricePerBarrelWellhead	44.72
CY2014	bkh	Average Natural Gas Liquids Price Per Mcfnymex AverageNaturalGasLiquidsPricePerMCFNYMEX	0.00
CY2015	bkh	Average Natural Gas Liquids Price Per Mcfnymex AverageNaturalGasLiquidsPricePerMCFNYMEX	0.00
CY2014	bkh	Average Natural Gas Liquids Price Per Mcf Wellhead AverageNaturalGasLiquidsPricePerMCFWellhead	34.81
CY2015	bkh	Average Natural Gas Liquids Price Per Mcf Wellhead AverageNaturalGasLiquidsPricePerMCFWellhead	18.96
CY2013	bkh	Average Natural Gas Price Per Mcfnymex AverageNaturalGasPricePerMCFNYMEX	3.67
CY2014	bkh	Average Natural Gas Price Per Mcfnymex AverageNaturalGasPricePerMCFNYMEX	4.35
CY2015	bkh	Average Natural Gas Price Per Mcfnymex AverageNaturalGasPricePerMCFNYMEX	2.59
CY2013	bkh	Average Natural Gas Price Per Mcf Wellhead AverageNaturalGasPricePerMCFWellhead	3.45
CY2014	bkh	Average Natural Gas Price Per Mcf Wellhead AverageNaturalGasPricePerMCFWellhead	3.33
CY2015	bkh	Average Natural Gas Price Per Mcf Wellhead AverageNaturalGasPricePerMCFWellhead	1.27
CY2015	bkh	Capital Expenditure For Proved Undeveloped Reserve CapitalExpenditureForProvedUndevelopedReserve	25300000	USD
CY2013	bkh	Capitalized Interest CapitalizedInterest	1061000	USD
CY2014	bkh	Capitalized Interest CapitalizedInterest	982000	USD
CY2015	bkh	Capitalized Interest CapitalizedInterest	1309000	USD
CY2015	bkh	Capitalized Interest Of Cost Excluded From Amortization CapitalizedInterestOfCostExcludedFromAmortization	3008000	USD
CY2015Q4	bkh	Corporate Units Ownership Interest Percentage In Subordinated Notes CorporateUnitsOwnershipInterestPercentageInSubordinatedNotes	0.05
CY2015Q4	bkh	Debt Instrument Convertible Consecutive Trading Daysfor Calculationof Applicable Market Value DebtInstrumentConvertibleConsecutiveTradingDaysforCalculationofApplicableMarketValue	P20D
CY2015Q4	bkh	Debt Instrument Convertible Conversion Ratio Basis Stated Principal Amount DebtInstrumentConvertibleConversionRatioBasisStatedPrincipalAmount	1000	USD
CY2015Q4	bkh	Debt Instrument Convertible If Applicable Market Value Greater Than Reference Price Amount Used To Calculate Numberof Shares Numerator DebtInstrumentConvertibleIfApplicableMarketValueGreaterThanReferencePriceAmountUsedToCalculateNumberofSharesNumerator	50
CY2015Q4	bkh	Debt Instrument Convertible Present Value Of Future Contract Adjustment Payments DebtInstrumentConvertiblePresentValueOfFutureContractAdjustmentPayments	33118000	USD
CY2015Q4	bkh	Debt Instrument Convertible Present Value Of Future Contract Adjustment Payments DebtInstrumentConvertiblePresentValueOfFutureContractAdjustmentPayments	33000000	USD
CY2015Q4	bkh	Debt Instrument Convertible Reference Price DebtInstrumentConvertibleReferencePrice	40.25
CY2014Q4	bkh	Deferred Tax Liabilities Development Operations DeferredTaxLiabilitiesDevelopmentOperations	109571000	USD
CY2015Q4	bkh	Deferred Tax Liabilities Development Operations DeferredTaxLiabilitiesDevelopmentOperations	183956000	USD
CY2014Q4	bkh	Deferred Tax Liability State DeferredTaxLiabilityState	36579000	USD
CY2015Q4	bkh	Deferred Tax Liability State DeferredTaxLiabilityState	35065000	USD
CY2015	bkh	Defined Contribution Plan Employee Vesting Period DefinedContributionPlanEmployeeVestingPeriod	P5Y
CY2013	bkh	Effective Income Tax Rate Reconciliation Allowance For Other Funds Used During Construction Equity EffectiveIncomeTaxRateReconciliationAllowanceForOtherFundsUsedDuringConstructionEquity	0.000
CY2014	bkh	Effective Income Tax Rate Reconciliation Allowance For Other Funds Used During Construction Equity EffectiveIncomeTaxRateReconciliationAllowanceForOtherFundsUsedDuringConstructionEquity	-0.001
CY2015	bkh	Effective Income Tax Rate Reconciliation Allowance For Other Funds Used During Construction Equity EffectiveIncomeTaxRateReconciliationAllowanceForOtherFundsUsedDuringConstructionEquity	-0.003
CY2013	bkh	Effective Income Tax Rate Reconciliation Flow Through Accounting EffectiveIncomeTaxRateReconciliationFlowThroughAccounting	-0.009
CY2014	bkh	Effective Income Tax Rate Reconciliation Flow Through Accounting EffectiveIncomeTaxRateReconciliationFlowThroughAccounting	-0.009
CY2015	bkh	Effective Income Tax Rate Reconciliation Flow Through Accounting EffectiveIncomeTaxRateReconciliationFlowThroughAccounting	-0.038
CY2013	bkh	Effective Tax Rate Reconciliation Investment Tax Credits And Excess Deferred EffectiveTaxRateReconciliationInvestmentTaxCreditsAndExcessDeferred	0.001
CY2014	bkh	Effective Tax Rate Reconciliation Investment Tax Credits And Excess Deferred EffectiveTaxRateReconciliationInvestmentTaxCreditsAndExcessDeferred	0.001
CY2015	bkh	Effective Tax Rate Reconciliation Investment Tax Credits And Excess Deferred EffectiveTaxRateReconciliationInvestmentTaxCreditsAndExcessDeferred	0.002
CY2015Q4	bkh	Equity Unit Annual Dividend Amount EquityUnitAnnualDividendAmount	2.125
CY2015Q4	bkh	Equity Unit Dividend Rate Percentage Annual EquityUnitDividendRatePercentageAnnual	0.0425
CY2015	bkh	Estimated Future Development Costsof Proved Undeveloped Wells EstimatedFutureDevelopmentCostsofProvedUndevelopedWells	400000	USD
CY2013	bkh	Finite Lived Intangible Asset Purchase Accounting Adjustments FiniteLivedIntangibleAssetPurchaseAccountingAdjustments	0	USD
CY2014	bkh	Finite Lived Intangible Asset Purchase Accounting Adjustments FiniteLivedIntangibleAssetPurchaseAccountingAdjustments	0	USD
CY2015	bkh	Finite Lived Intangible Asset Purchase Accounting Adjustments FiniteLivedIntangibleAssetPurchaseAccountingAdjustments	434000	USD
CY2013	bkh	Fuel Purchased Power And Cost Of Gas Sold FuelPurchasedPowerAndCostOfGasSold	492147000	USD
CY2014	bkh	Fuel Purchased Power And Cost Of Gas Sold FuelPurchasedPowerAndCostOfGasSold	581782000	USD
CY2015	bkh	Fuel Purchased Power And Cost Of Gas Sold FuelPurchasedPowerAndCostOfGasSold	456887000	USD
CY2014Q4	bkh	Gross Amounts Offset In Statement Of Financial Position Assets GrossAmountsOffsetInStatementOfFinancialPositionAssets	17546000	USD
CY2015Q4	bkh	Gross Amounts Offset In Statement Of Financial Position Assets GrossAmountsOffsetInStatementOfFinancialPositionAssets	12937000	USD
CY2014Q4	bkh	Gross Amounts Offset In Statement Of Financial Position Liabilities GrossAmountsOffsetInStatementOfFinancialPositionLiabilities	19776000	USD
CY2015Q4	bkh	Gross Amounts Offset In Statement Of Financial Position Liabilities GrossAmountsOffsetInStatementOfFinancialPositionLiabilities	25141000	USD
CY2013	bkh	Investment Tax Credit Amortization InvestmentTaxCreditAmortization	212000	USD
CY2014	bkh	Investment Tax Credit Amortization InvestmentTaxCreditAmortization	206000	USD
CY2015	bkh	Investment Tax Credit Amortization InvestmentTaxCreditAmortization	113000	USD
CY2014Q4	bkh	Net Derivative Position Assets NetDerivativePositionAssets	0	USD
CY2015Q4	bkh	Net Derivative Position Assets NetDerivativePositionAssets	3441000	USD
CY2014Q4	bkh	Net Derivative Position Liabilities NetDerivativePositionLiabilities	-1465000	USD
CY2015Q4	bkh	Net Derivative Position Liabilities NetDerivativePositionLiabilities	-4048000	USD
CY2013	bkh	Non Cash Revision To Capitalized Asset Retirement Costs NonCashRevisionToCapitalizedAssetRetirementCosts	1235000	USD
CY2014	bkh	Non Cash Revision To Capitalized Asset Retirement Costs NonCashRevisionToCapitalizedAssetRetirementCosts	-5634000	USD
CY2015	bkh	Non Cash Revision To Capitalized Asset Retirement Costs NonCashRevisionToCapitalizedAssetRetirementCosts	-518000	USD
CY2015	bkh	Number Of Business Groups NumberOfBusinessGroups	2	Business_Group
CY2013	bkh	Operating Costs Nonregulated Energy Operations OperatingCostsNonregulatedEnergyOperations	83762000	USD
CY2014	bkh	Operating Costs Nonregulated Energy Operations OperatingCostsNonregulatedEnergyOperations	88141000	USD
CY2015	bkh	Operating Costs Nonregulated Energy Operations OperatingCostsNonregulatedEnergyOperations	88702000	USD
CY2015	bkh	Premiumon Publicly Traded Equity Units Known As Corporate Units PremiumonPubliclyTradedEquityUnitsKnownAsCorporateUnits	33118000	USD
CY2015Q4	bkh	Proved Undeveloped Reserve Locations ProvedUndevelopedReserveLocations	6.000000	PUD_Location
CY2015	bkh	Proved Undeveloped Reserves ProvedUndevelopedReserves	100000	Mcfe
CY2015	bkh	Proved Undeveloped Reserves Extensions Discoveries And Additions ProvedUndevelopedReservesExtensionsDiscoveriesAndAdditions	27000000	Mcfe
CY2015	bkh	Proved Undeveloped Reserves Revisions Of Previous Estimates ProvedUndevelopedReservesRevisionsOfPreviousEstimates	-10100000	Mcfe
CY2013	bkh	Public Utilities Allowance For Funds Used During Construction Borrowed Interest Costs Capitalized PublicUtilitiesAllowanceForFundsUsedDuringConstructionBorrowedInterestCostsCapitalized	1130000	USD
CY2014	bkh	Public Utilities Allowance For Funds Used During Construction Borrowed Interest Costs Capitalized PublicUtilitiesAllowanceForFundsUsedDuringConstructionBorrowedInterestCostsCapitalized	1075000	USD
CY2015	bkh	Public Utilities Allowance For Funds Used During Construction Borrowed Interest Costs Capitalized PublicUtilitiesAllowanceForFundsUsedDuringConstructionBorrowedInterestCostsCapitalized	1250000	USD
CY2015Q4	bkh	Pud Developed Pud Location PudDevelopedPudLocation	6	PUD_Location
CY2015Q4	bkh	Pud Locations In Reserves For Five Or More Years PudLocationsInReservesForFiveOrMoreYears	0	PUD_Location
CY2015	bkh	Reserves Replaced ReservesReplaced	2.09
CY2015	bkh	Securities Excluded From Diluted Earnings Per Share Due To Net Loss SecuritiesExcludedFromDilutedEarningsPerShareDueToNetLoss	83000	shares
CY2013	bkh	Total Other Income Expense TotalOtherIncomeExpense	-78012000	USD
CY2014	bkh	Total Other Income Expense TotalOtherIncomeExpense	-66353000	USD
CY2015	bkh	Total Other Income Expense TotalOtherIncomeExpense	-79317000	USD
CY2015	dei	Amendment Flag AmendmentFlag	false
CY2015	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2015	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2015	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2015
CY2015	dei	Document Period End Date DocumentPeriodEndDate	2015-12-31
CY2015	dei	Document Type DocumentType	10-K
CY2015	dei	Entity Central Index Key EntityCentralIndexKey	0001130464
CY2016Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	51194387	shares
CY2015	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2015	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2015Q2	dei	Entity Public Float EntityPublicFloat	1925452517	USD
CY2015	dei	Entity Registrant Name EntityRegistrantName	BLACK HILLS CORP /SD/
CY2015	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2015	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2014Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	124139000	USD
CY2015Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	105468000	USD
CY2014Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	189992000	USD
CY2015Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	147486000	USD
CY2013	us-gaap	Accretion Of Discount AccretionOfDiscount	15126000	USD
CY2014	us-gaap	Accretion Of Discount AccretionOfDiscount	18437000	USD
CY2015	us-gaap	Accretion Of Discount AccretionOfDiscount	18870000	USD
CY2014Q4	us-gaap	Accrual For Taxes Other Than Income Taxes Current AccrualForTaxesOtherThanIncomeTaxesCurrent	33688000	USD
CY2015Q4	us-gaap	Accrual For Taxes Other Than Income Taxes Current AccrualForTaxesOtherThanIncomeTaxesCurrent	32393000	USD
CY2014Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	170115000	USD
CY2015Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	232061000	USD
CY2014Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	1357929000	USD
CY2015Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	1717684000	USD
CY2013Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-17422000	USD
CY2014Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-15044000	USD
CY2015Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-9055000	USD
CY2015	us-gaap	Acquisition Costs AcquisitionCosts	19170000	USD
CY2014Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	748840000	USD
CY2015Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	953044000	USD
CY2013	us-gaap	Adjustment To Additional Paid In Capital Income Tax Effect From Share Based Compensation Net AdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet	410000	USD
CY2014	us-gaap	Adjustment To Additional Paid In Capital Income Tax Effect From Share Based Compensation Net AdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet	-499000	USD
CY2015	us-gaap	Adjustment To Additional Paid In Capital Income Tax Effect From Share Based Compensation Net AdjustmentToAdditionalPaidInCapitalIncomeTaxEffectFromShareBasedCompensationNet	0	USD
CY2015	us-gaap	Adjustments To Additional Paid In Capital Stock Issued Issuance Costs AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts	17926000	USD
CY2014Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	1516000	USD
CY2015Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	1741000	USD
CY2013	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	4262000	USD
CY2014	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	1025000	USD
CY2015	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	5113000	USD
CY2013	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	6763000	USD
CY2014	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	2127000	USD
CY2015	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	6364000	USD
CY2013	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	223000	USD
CY2014	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	221000	USD
CY2015	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	230000	USD
CY2013	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	22000	shares
CY2014	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	81000	shares
CY2015	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	6552000	shares
CY2013Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	51851000	USD
CY2014Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	47386000	USD
CY2015Q4	us-gaap	Asset Retirement Obligation AssetRetirementObligation	44735000	USD
CY2014	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	2186000	USD
CY2015	us-gaap	Asset Retirement Obligation Accretion Expense AssetRetirementObligationAccretionExpense	2560000	USD
CY2014	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	413000	USD
CY2015	us-gaap	Asset Retirement Obligation Liabilities Incurred AssetRetirementObligationLiabilitiesIncurred	828000	USD
CY2014	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	1017000	USD
CY2015	us-gaap	Asset Retirement Obligation Liabilities Settled AssetRetirementObligationLiabilitiesSettled	4693000	USD
CY2014	us-gaap	Asset Retirement Obligation Revision Of Estimate AssetRetirementObligationRevisionOfEstimate	-6047000	USD
CY2015	us-gaap	Asset Retirement Obligation Revision Of Estimate AssetRetirementObligationRevisionOfEstimate	-1346000	USD
CY2014Q4	us-gaap	Assets Assets	4245902000	USD
CY2015Q4	us-gaap	Assets Assets	4655501000	USD
CY2014Q4	us-gaap	Assets Current AssetsCurrent	454036000	USD
CY2015Q4	us-gaap	Assets Current AssetsCurrent	822151000	USD
CY2014Q4	us-gaap	Assets Noncurrent AssetsNoncurrent	569101000	USD
CY2015Q4	us-gaap	Assets Noncurrent AssetsNoncurrent	562271000	USD
CY2013	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	59811000	USD
CY2014	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	52584000	USD
CY2015	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	40250000	USD
CY2013Q4	us-gaap	Capitalized Costs Accumulated Depreciation Depletion Amortization And Valuation Allowance For Relating To Oil And Gas Producing Activities CapitalizedCostsAccumulatedDepreciationDepletionAmortizationAndValuationAllowanceForRelatingToOilAndGasProducingActivities	592505000	USD
CY2014Q4	us-gaap	Capitalized Costs Accumulated Depreciation Depletion Amortization And Valuation Allowance For Relating To Oil And Gas Producing Activities CapitalizedCostsAccumulatedDepreciationDepletionAmortizationAndValuationAllowanceForRelatingToOilAndGasProducingActivities	612012000	USD
CY2015Q4	us-gaap	Capitalized Costs Accumulated Depreciation Depletion Amortization And Valuation Allowance For Relating To Oil And Gas Producing Activities CapitalizedCostsAccumulatedDepreciationDepletionAmortizationAndValuationAllowanceForRelatingToOilAndGasProducingActivities	888775000	USD
CY2015	us-gaap	Capitalized Costs Of Unproved Properties Excluded From Amortization CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortization	68107000	USD
CY2013Q4	us-gaap	Capitalized Costs Oil And Gas Producing Activities Gross CapitalizedCostsOilAndGasProducingActivitiesGross	787898000	USD
CY2014Q4	us-gaap	Capitalized Costs Oil And Gas Producing Activities Gross CapitalizedCostsOilAndGasProducingActivitiesGross	882847000	USD
CY2015Q4	us-gaap	Capitalized Costs Oil And Gas Producing Activities Gross CapitalizedCostsOilAndGasProducingActivitiesGross	1055720000	USD
CY2013Q4	us-gaap	Capitalized Costs Oil And Gas Producing Activities Net CapitalizedCostsOilAndGasProducingActivitiesNet	195393000	USD
CY2014Q4	us-gaap	Capitalized Costs Oil And Gas Producing Activities Net CapitalizedCostsOilAndGasProducingActivitiesNet	270835000	USD
CY2015Q4	us-gaap	Capitalized Costs Oil And Gas Producing Activities Net CapitalizedCostsOilAndGasProducingActivitiesNet	166945000	USD
CY2013Q4	us-gaap	Capitalized Costs Proved Properties CapitalizedCostsProvedProperties	725345000	USD
CY2014Q4	us-gaap	Capitalized Costs Proved Properties CapitalizedCostsProvedProperties	807518000	USD
CY2015Q4	us-gaap	Capitalized Costs Proved Properties CapitalizedCostsProvedProperties	1008466000	USD
CY2013Q4	us-gaap	Capitalized Costs Unproved Properties CapitalizedCostsUnprovedProperties	62553000	USD
CY2014Q4	us-gaap	Capitalized Costs Unproved Properties CapitalizedCostsUnprovedProperties	75329000	USD
CY2015Q4	us-gaap	Capitalized Costs Unproved Properties CapitalizedCostsUnprovedProperties	47254000	USD
CY2014Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	21218000	USD
CY2015Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	456535000	USD
CY2012Q4	us-gaap	Cash And Cash Equivalents At Carrying Value Including Discontinued Operations CashAndCashEquivalentsAtCarryingValueIncludingDiscontinuedOperations	15462000	USD
CY2013Q4	us-gaap	Cash And Cash Equivalents At Carrying Value Including Discontinued Operations CashAndCashEquivalentsAtCarryingValueIncludingDiscontinuedOperations	7841000	USD
CY2014Q4	us-gaap	Cash And Cash Equivalents At Carrying Value Including Discontinued Operations CashAndCashEquivalentsAtCarryingValueIncludingDiscontinuedOperations	21218000	USD
CY2015Q4	us-gaap	Cash And Cash Equivalents At Carrying Value Including Discontinued Operations CashAndCashEquivalentsAtCarryingValueIncludingDiscontinuedOperations	456535000	USD
CY2013	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	-7621000	USD
CY2014	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	13377000	USD
CY2015	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	435317000	USD
CY2013	us-gaap	Cash Provided By Used In Financing Activities Discontinued Operations CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations	0	USD
CY2014	us-gaap	Cash Provided By Used In Financing Activities Discontinued Operations CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations	0	USD
CY2015	us-gaap	Cash Provided By Used In Financing Activities Discontinued Operations CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations	0	USD
CY2013	us-gaap	Cash Provided By Used In Investing Activities Discontinued Operations CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations	0	USD
CY2014	us-gaap	Cash Provided By Used In Investing Activities Discontinued Operations CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations	0	USD
CY2015	us-gaap	Cash Provided By Used In Investing Activities Discontinued Operations CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations	0	USD
CY2013	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	-884000	USD
CY2014	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	0	USD
CY2015	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	0	USD
CY2014Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2015Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2013	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.52
CY2014Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.390
CY2014Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.390
CY2014Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.390
CY2014Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.390
CY2014	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.56
CY2015Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.405
CY2015Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.405
CY2015Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.405
CY2015Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.405
CY2015	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.62
CY2014Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1
CY2015Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1
CY2014Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000	shares
CY2015Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000	shares
CY2014Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	44714072	shares
CY2015Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	51231861	shares
CY2014Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	44671846	shares
CY2015Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	51192141	shares
CY2014Q4	us-gaap	Common Stock Value CommonStockValue	44714000	USD
CY2015Q4	us-gaap	Common Stock Value CommonStockValue	51232000	USD
CY2013	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	135489000	USD
CY2014	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	133267000	USD
CY2015	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-26122000	USD
CY2013	us-gaap	Costs And Expenses CostsAndExpenses	386936000	USD
CY2014	us-gaap	Costs And Expenses CostsAndExpenses	403175000	USD
CY2015	us-gaap	Costs And Expenses CostsAndExpenses	412945000	USD
CY2013	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-2003000	USD
CY2014	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-2319000	USD
CY2015	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	2549000	USD
CY2013	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	-2176000	USD
CY2014	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	-3607000	USD
CY2015	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	3868000	USD
CY2013	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	-173000	USD
CY2014	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	-1288000	USD
CY2015	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	1319000	USD
CY2014Q4	us-gaap	Customer Advances And Deposits Current CustomerAdvancesAndDepositsCurrent	26141000	USD
CY2015Q4	us-gaap	Customer Advances And Deposits Current CustomerAdvancesAndDepositsCurrent	53496000	USD
CY2013	us-gaap	Decrease Due To Sales Of Minerals In Place DecreaseDueToSalesOfMineralsInPlace	869000	USD
CY2014	us-gaap	Decrease Due To Sales Of Minerals In Place DecreaseDueToSalesOfMineralsInPlace	0	USD
CY2015	us-gaap	Decrease Due To Sales Of Minerals In Place DecreaseDueToSalesOfMineralsInPlace	0	USD
CY2013	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	58288000	USD
CY2014	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	64780000	USD
CY2015	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-23592000	USD
CY2015Q4	us-gaap	Deferred Finance Costs Noncurrent Net DeferredFinanceCostsNoncurrentNet	11379000	USD
CY2013	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	65216000	USD
CY2014	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	70232000	USD
CY2015	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-26028000	USD
CY2014Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	917738000	USD
CY2015Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	1001821000	USD
CY2013	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	7140000	USD
CY2014	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	5658000	USD
CY2015	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-2323000	USD
CY2014Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	454074000	USD
CY2015Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	551242000	USD
CY2014Q4	us-gaap	Deferred Tax Assets Net Current DeferredTaxAssetsNetCurrent	48288000	USD
CY2015Q4	us-gaap	Deferred Tax Assets Net Current DeferredTaxAssetsNetCurrent	0	USD
CY2014Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	213466000	USD
CY2015Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	217922000	USD
CY2014Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	76005000	USD
CY2015Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	85907000	USD
CY2014Q4	us-gaap	Deferred Tax Assets Regulatory Assets And Liabilities DeferredTaxAssetsRegulatoryAssetsAndLiabilities	49243000	USD
CY2015Q4	us-gaap	Deferred Tax Assets Regulatory Assets And Liabilities DeferredTaxAssetsRegulatoryAssetsAndLiabilities	43586000	USD
CY2014Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	26714000	USD
CY2015Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	26400000	USD
CY2014Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Impairment Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses	93663000	USD
CY2015Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Impairment Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses	181731000	USD
CY2014Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	5017000	USD
CY2015Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	4304000	USD
CY2014Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	463664000	USD
CY2015Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	450579000	USD
CY2014Q4	us-gaap	Deferred Tax Liabilities Deferred Expense DeferredTaxLiabilitiesDeferredExpense	35284000	USD
CY2015Q4	us-gaap	Deferred Tax Liabilities Deferred Expense DeferredTaxLiabilitiesDeferredExpense	26121000	USD
CY2014Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	511952000	USD
CY2015Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	450579000	USD
CY2014Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	15684000	USD
CY2015Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	18519000	USD
CY2014Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	695280000	USD
CY2015Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	709068000	USD
CY2014Q4	us-gaap	Deferred Tax Liabilities Regulatory Assets DeferredTaxLiabilitiesRegulatoryAssets	25340000	USD
CY2015Q4	us-gaap	Deferred Tax Liabilities Regulatory Assets DeferredTaxLiabilitiesRegulatoryAssets	29092000	USD
CY2015	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.0675
CY2015	us-gaap	Defined Benefit Plan Effect Of One Percentage Point Decrease On Accumulated Postretirement Benefit Obligation1 DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnAccumulatedPostretirementBenefitObligation1	2088000	USD
CY2015	us-gaap	Defined Benefit Plan Effect Of One Percentage Point Decrease On Service And Interest Cost Components1 DefinedBenefitPlanEffectOfOnePercentagePointDecreaseOnServiceAndInterestCostComponents1	141000	USD
CY2015	us-gaap	Defined Benefit Plan Effect Of One Percentage Point Increase On Accumulated Postretirement Benefit Obligation DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnAccumulatedPostretirementBenefitObligation	2471000	USD
CY2015	us-gaap	Defined Benefit Plan Effect Of One Percentage Point Increase On Service And Interest Cost Components DefinedBenefitPlanEffectOfOnePercentagePointIncreaseOnServiceAndInterestCostComponents	173000	USD
CY2015	us-gaap	Defined Benefit Plan Measurement Date DefinedBenefitPlanMeasurementDate	December 31
CY2014	us-gaap	Defined Benefit Plan Target Plan Asset Allocations DefinedBenefitPlanTargetPlanAssetAllocations	1
CY2015	us-gaap	Defined Benefit Plan Target Plan Asset Allocations DefinedBenefitPlanTargetPlanAssetAllocations	1
CY2015	us-gaap	Defined Benefit Plans Estimated Future Employer Contributions In Next Fiscal Year DefinedBenefitPlansEstimatedFutureEmployerContributionsInNextFiscalYear	10000000	USD
CY2015	us-gaap	Defined Contribution Plan Employers Matching Contribution Annual Vesting Percentage DefinedContributionPlanEmployersMatchingContributionAnnualVestingPercentage	0.2
CY2015	us-gaap	Defined Contribution Plan Maximum Annual Contributions Per Employee Percent DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent	0.5
CY2013	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	137324000	USD
CY2014	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	144745000	USD
CY2015	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	155370000	USD
CY2014Q4	us-gaap	Derivative Assets DerivativeAssets	0	USD
CY2015Q4	us-gaap	Derivative Assets DerivativeAssets	3441000	USD
CY2014Q4	us-gaap	Derivative Assets Current DerivativeAssetsCurrent	0	USD
CY2015Q4	us-gaap	Derivative Assets Current DerivativeAssetsCurrent	0	USD
CY2014Q4	us-gaap	Derivative Assets Noncurrent DerivativeAssetsNoncurrent	0	USD
CY2015Q4	us-gaap	Derivative Assets Noncurrent DerivativeAssetsNoncurrent	3441000	USD
CY2014Q4	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	0	USD
CY2015Q4	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	0	USD
CY2014Q4	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	7485000	USD
CY2015Q4	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	7039000	USD
CY2014Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	17546000	USD
CY2015Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	16378000	USD
CY2014Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	25796000	USD
CY2015Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	28132000	USD
CY2013	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	17267000	USD
CY2014	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	0	USD
CY2015	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	0	USD
CY2014Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	6020000	USD
CY2015Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	2991000	USD
CY2014Q4	us-gaap	Derivative Liabilities Current DerivativeLiabilitiesCurrent	3340000	USD
CY2015Q4	us-gaap	Derivative Liabilities Current DerivativeLiabilitiesCurrent	2835000	USD
CY2014Q4	us-gaap	Derivative Liabilities Noncurrent DerivativeLiabilitiesNoncurrent	2680000	USD
CY2015Q4	us-gaap	Derivative Liabilities Noncurrent DerivativeLiabilitiesNoncurrent	156000	USD
CY2013	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	67587000	USD
CY2014	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	69636000	USD
CY2015	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	72604000	USD
CY2013	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.66
CY2014Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.10
CY2014Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.46
CY2014Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.61
CY2014Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.78
CY2014	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.95
CY2015Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.76
CY2015Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.94
CY2015Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.22
CY2015Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.30
CY2015	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-0.71
CY2013	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.64
CY2014Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.09
CY2014Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.46
CY2014Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.61
CY2014Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.77
CY2014	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.93
CY2015Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.76
CY2015Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.94
CY2015Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.22
CY2015Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.30
CY2015	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-0.71
CY2013	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.348
CY2014	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.337
CY2015	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	-0.408
CY2013	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.350
CY2014	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.350
CY2015	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	-0.350
CY2013	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Depletion EffectiveIncomeTaxRateReconciliationNondeductibleExpenseDepletion	-0.009
CY2014	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Depletion EffectiveIncomeTaxRateReconciliationNondeductibleExpenseDepletion	-0.010
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Depletion EffectiveIncomeTaxRateReconciliationNondeductibleExpenseDepletion	-0.035
CY2013	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.009
CY2014	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.001
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.000
CY2013	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.024
CY2014	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.011
CY2015	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	-0.010
CY2013	us-gaap	Effective Income Tax Rate Reconciliation Tax Contingencies EffectiveIncomeTaxRateReconciliationTaxContingencies	0.007
CY2014	us-gaap	Effective Income Tax Rate Reconciliation Tax Contingencies EffectiveIncomeTaxRateReconciliationTaxContingencies	-0.001
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Tax Contingencies EffectiveIncomeTaxRateReconciliationTaxContingencies	0.035
CY2013	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.005
CY2014	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.001
CY2015	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.005
CY2014Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	45192000	USD
CY2015Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	43342000	USD
CY2015Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	7700000	USD
CY2015	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P1Y8M
CY2014Q4	us-gaap	Energy Related Inventory Natural Gas In Storage EnergyRelatedInventoryNaturalGasInStorage	34999000	USD
CY2015Q4	us-gaap	Energy Related Inventory Natural Gas In Storage EnergyRelatedInventoryNaturalGasInStorage	25650000	USD
CY2014Q4	us-gaap	Energy Related Inventory Other Fossil Fuel EnergyRelatedInventoryOtherFossilFuel	6637000	USD
CY2015Q4	us-gaap	Energy Related Inventory Other Fossil Fuel EnergyRelatedInventoryOtherFossilFuel	5567000	USD
CY2013	us-gaap	Equity Method Investment Other Than Temporary Impairment EquityMethodInvestmentOtherThanTemporaryImpairment	0	USD
CY2014	us-gaap	Equity Method Investment Other Than Temporary Impairment EquityMethodInvestmentOtherThanTemporaryImpairment	0	USD
CY2015	us-gaap	Equity Method Investment Other Than Temporary Impairment EquityMethodInvestmentOtherThanTemporaryImpairment	4405000	USD
CY2015	us-gaap	Exploration Costs ExplorationCosts	45929000	USD
CY2013	us-gaap	Extensions Discoveries Additions And Improved Recovery Less Related Costs ExtensionsDiscoveriesAdditionsAndImprovedRecoveryLessRelatedCosts	29574000	USD
CY2014	us-gaap	Extensions Discoveries Additions And Improved Recovery Less Related Costs ExtensionsDiscoveriesAdditionsAndImprovedRecoveryLessRelatedCosts	17582000	USD
CY2015	us-gaap	Extensions Discoveries Additions And Improved Recovery Less Related Costs ExtensionsDiscoveriesAdditionsAndImprovedRecoveryLessRelatedCosts	15718000	USD
CY2014Q4	us-gaap	Fair Value Assets Level1 To Level2 Transfers Amount FairValueAssetsLevel1ToLevel2TransfersAmount	0	USD
CY2015Q4	us-gaap	Fair Value Assets Level1 To Level2 Transfers Amount FairValueAssetsLevel1ToLevel2TransfersAmount	0	USD
CY2014Q4	us-gaap	Fair Value Assets Level2 To Level1 Transfers Amount FairValueAssetsLevel2ToLevel1TransfersAmount	0	USD
CY2015Q4	us-gaap	Fair Value Assets Level2 To Level1 Transfers Amount FairValueAssetsLevel2ToLevel1TransfersAmount	0	USD
CY2014Q4	us-gaap	Fair Value Liabilities Level1 To Level2 Transfers Amount FairValueLiabilitiesLevel1ToLevel2TransfersAmount	0	USD
CY2015Q4	us-gaap	Fair Value Liabilities Level1 To Level2 Transfers Amount FairValueLiabilitiesLevel1ToLevel2TransfersAmount	0	USD
CY2014Q4	us-gaap	Fair Value Liabilities Level2 To Level1 Transfers Amount FairValueLiabilitiesLevel2ToLevel1TransfersAmount	0	USD
CY2015Q4	us-gaap	Fair Value Liabilities Level2 To Level1 Transfers Amount FairValueLiabilitiesLevel2ToLevel1TransfersAmount	0	USD
CY2015	us-gaap	Finite Lived Intangible Asset Useful Life FiniteLivedIntangibleAssetUsefulLife	P25Y
CY2015Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	200000	USD
CY2015Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	200000	USD
CY2015Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	200000	USD
CY2015Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	200000	USD
CY2015Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	200000	USD
CY2013Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Cash Inflows FutureNetCashFlowsRelatingToProvedOilAndGasReservesCashInflows	602501000	USD
CY2014Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Cash Inflows FutureNetCashFlowsRelatingToProvedOilAndGasReservesCashInflows	675973000	USD
CY2015Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Cash Inflows FutureNetCashFlowsRelatingToProvedOilAndGasReservesCashInflows	295173000	USD
CY2013Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Development Costs FutureNetCashFlowsRelatingToProvedOilAndGasReservesDevelopmentCosts	40557000	USD
CY2014Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Development Costs FutureNetCashFlowsRelatingToProvedOilAndGasReservesDevelopmentCosts	45123000	USD
CY2015Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Development Costs FutureNetCashFlowsRelatingToProvedOilAndGasReservesDevelopmentCosts	24833000	USD
CY2013Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Income Tax Expense FutureNetCashFlowsRelatingToProvedOilAndGasReservesIncomeTaxExpense	81566000	USD
CY2014Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Income Tax Expense FutureNetCashFlowsRelatingToProvedOilAndGasReservesIncomeTaxExpense	29523000	USD
CY2015Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Income Tax Expense FutureNetCashFlowsRelatingToProvedOilAndGasReservesIncomeTaxExpense	0	USD
CY2013Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Net Cash Flows FutureNetCashFlowsRelatingToProvedOilAndGasReservesNetCashFlows	266800000	USD
CY2014Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Net Cash Flows FutureNetCashFlowsRelatingToProvedOilAndGasReservesNetCashFlows	356147000	USD
CY2015Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Net Cash Flows FutureNetCashFlowsRelatingToProvedOilAndGasReservesNetCashFlows	123788000	USD
CY2013Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Production Costs FutureNetCashFlowsRelatingToProvedOilAndGasReservesProductionCosts	213578000	USD
CY2014Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Production Costs FutureNetCashFlowsRelatingToProvedOilAndGasReservesProductionCosts	245180000	USD
CY2015Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Production Costs FutureNetCashFlowsRelatingToProvedOilAndGasReservesProductionCosts	146552000	USD
CY2013Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Ten Percent Annual Discount For Estimated Timing Of Cash Flows FutureNetCashFlowsRelatingToProvedOilAndGasReservesTenPercentAnnualDiscountForEstimatedTimingOfCashFlows	107375000	USD
CY2014Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Ten Percent Annual Discount For Estimated Timing Of Cash Flows FutureNetCashFlowsRelatingToProvedOilAndGasReservesTenPercentAnnualDiscountForEstimatedTimingOfCashFlows	173125000	USD
CY2015Q4	us-gaap	Future Net Cash Flows Relating To Proved Oil And Gas Reserves Ten Percent Annual Discount For Estimated Timing Of Cash Flows FutureNetCashFlowsRelatingToProvedOilAndGasReservesTenPercentAnnualDiscountForEstimatedTimingOfCashFlows	44760000	USD
CY2015Q4	us-gaap	Gas And Oil Area Undeveloped Net GasAndOilAreaUndevelopedNet	236545	acre
CY2013Q4	us-gaap	Goodwill Goodwill	353396000	USD
CY2014Q4	us-gaap	Goodwill Goodwill	353396000	USD
CY2015Q4	us-gaap	Goodwill Goodwill	359759000	USD
CY2014	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	0	USD
CY2015	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	6363000	USD
CY2015Q4	us-gaap	Guarantee Obligations Maximum Exposure GuaranteeObligationsMaximumExposure	159491000	USD
CY2015	us-gaap	Guarantee Obligations Term GuaranteeObligationsTerm	12/31/2016
CY2013	us-gaap	Impairment Of Long Lived Assets Held For Use ImpairmentOfLongLivedAssetsHeldForUse	0	USD
CY2014	us-gaap	Impairment Of Long Lived Assets Held For Use ImpairmentOfLongLivedAssetsHeldForUse	0	USD
CY2015	us-gaap	Impairment Of Long Lived Assets Held For Use ImpairmentOfLongLivedAssetsHeldForUse	249608000	USD
CY2013	us-gaap	Impairment Of Oil And Gas Properties ImpairmentOfOilAndGasProperties	0	USD
CY2014	us-gaap	Impairment Of Oil And Gas Properties ImpairmentOfOilAndGasProperties	0	USD
CY2015	us-gaap	Impairment Of Oil And Gas Properties ImpairmentOfOilAndGasProperties	254013000	USD
CY2013	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	118307000	USD
CY2014Q1	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	48645000	USD
CY2014Q2	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	20347000	USD
CY2014Q3	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	27363000	USD
CY2014Q4	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	34534000	USD
CY2014	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	130889000	USD
CY2015Q1	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	33850000	USD
CY2015Q2	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-41842000	USD
CY2015Q3	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-9943000	USD
CY2015Q4	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-14176000	USD
CY2015	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-32111000	USD
CY2013	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	181433000	USD
CY2014	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	197515000	USD
CY2015	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	-49522000	USD
CY2013	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	118307000	USD
CY2014	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	130889000	USD
CY2015	us-gaap	Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest	-32111000	USD
CY2013	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	2.68
CY2014	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	2.95
CY2015	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-0.71
CY2013	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	2.66
CY2014	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	2.93
CY2015	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-0.71
CY2013	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	-884000	USD
CY2014	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	0	USD
CY2015	us-gaap	Income Loss From Discontinued Operations Net Of Tax IncomeLossFromDiscontinuedOperationsNetOfTax	0	USD
CY2013	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	-0.02
CY2014	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.00
CY2015	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.00
CY2013	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	-0.02
CY2014	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.00
CY2015	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.00
CY2013	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	-86000	USD
CY2014	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	-1000	USD
CY2015	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	-344000	USD
CY2013	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	63040000	USD
CY2014	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	66625000	USD
CY2015	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-22160000	USD
CY2013	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	4573000	USD
CY2014	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	413000	USD
CY2015	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	1202000	USD
CY2014Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	2053000	USD
CY2015Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	368000	USD
CY2013	us-gaap	Increase Decrease In Accounts Receivable And Other Operating Assets IncreaseDecreaseInAccountsReceivableAndOtherOperatingAssets	18945000	USD
CY2014	us-gaap	Increase Decrease In Accounts Receivable And Other Operating Assets IncreaseDecreaseInAccountsReceivableAndOtherOperatingAssets	18684000	USD
CY2015	us-gaap	Increase Decrease In Accounts Receivable And Other Operating Assets IncreaseDecreaseInAccountsReceivableAndOtherOperatingAssets	-40125000	USD
CY2013	us-gaap	Increase Decrease In Estimated Future Development Costs IncreaseDecreaseInEstimatedFutureDevelopmentCosts	-12216000	USD
CY2014	us-gaap	Increase Decrease In Estimated Future Development Costs IncreaseDecreaseInEstimatedFutureDevelopmentCosts	3195000	USD
CY2015	us-gaap	Increase Decrease In Estimated Future Development Costs IncreaseDecreaseInEstimatedFutureDevelopmentCosts	-7387000	USD
CY2013	us-gaap	Increase Decrease In Future Income Tax Expense Estimates On Future Cash Flows Related To Proved Oil And Gas Reserves IncreaseDecreaseInFutureIncomeTaxExpenseEstimatesOnFutureCashFlowsRelatedToProvedOilAndGasReserves	-3892000	USD
CY2014	us-gaap	Increase Decrease In Future Income Tax Expense Estimates On Future Cash Flows Related To Proved Oil And Gas Reserves IncreaseDecreaseInFutureIncomeTaxExpenseEstimatesOnFutureCashFlowsRelatedToProvedOilAndGasReserves	19265000	USD
CY2015	us-gaap	Increase Decrease In Future Income Tax Expense Estimates On Future Cash Flows Related To Proved Oil And Gas Reserves IncreaseDecreaseInFutureIncomeTaxExpenseEstimatesOnFutureCashFlowsRelatedToProvedOilAndGasReserves	5682000	USD
CY2013	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	5770000	USD
CY2014	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	4563000	USD
CY2015	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-7197000	USD
CY2013	us-gaap	Increase Decrease In Other Accounts Payable And Accrued Liabilities IncreaseDecreaseInOtherAccountsPayableAndAccruedLiabilities	15336000	USD
CY2014	us-gaap	Increase Decrease In Other Accounts Payable And Accrued Liabilities IncreaseDecreaseInOtherAccountsPayableAndAccruedLiabilities	16027000	USD
CY2015	us-gaap	Increase Decrease In Other Accounts Payable And Accrued Liabilities IncreaseDecreaseInOtherAccountsPayableAndAccruedLiabilities	-1070000	USD
CY2013	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-312000	USD
CY2014	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-733000	USD
CY2015	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	9034000	USD
CY2013	us-gaap	Increase Decrease In Other Regulatory Assets IncreaseDecreaseInOtherRegulatoryAssets	-8323000	USD
CY2014	us-gaap	Increase Decrease In Other Regulatory Assets IncreaseDecreaseInOtherRegulatoryAssets	38774000	USD
CY2015	us-gaap	Increase Decrease In Other Regulatory Assets IncreaseDecreaseInOtherRegulatoryAssets	-21883000	USD
CY2013	us-gaap	Increase Decrease In Regulatory Liabilities IncreaseDecreaseInRegulatoryLiabilities	-3299000	USD
CY2014	us-gaap	Increase Decrease In Regulatory Liabilities IncreaseDecreaseInRegulatoryLiabilities	-7633000	USD
CY2015	us-gaap	Increase Decrease In Regulatory Liabilities IncreaseDecreaseInRegulatoryLiabilities	1675000	USD
CY2013	us-gaap	Increase Due To Purchases Of Minerals In Place IncreaseDueToPurchasesOfMineralsInPlace	0	USD
CY2014	us-gaap	Increase Due To Purchases Of Minerals In Place IncreaseDueToPurchasesOfMineralsInPlace	0	USD
CY2015	us-gaap	Increase Due To Purchases Of Minerals In Place IncreaseDueToPurchasesOfMineralsInPlace	0	USD
CY2013	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	256000	shares
CY2014	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	204000	shares
CY2015	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	0	shares
CY2012Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	3620000	USD
CY2013Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	3397000	USD
CY2014Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	3176000	USD
CY2015Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	3380000	USD
CY2013	us-gaap	Interest Costs Incurred InterestCostsIncurred	113979000	USD
CY2014	us-gaap	Interest Costs Incurred InterestCostsIncurred	73017000	USD
CY2015	us-gaap	Interest Costs Incurred InterestCostsIncurred	86278000	USD
CY2013	us-gaap	Interest Expense InterestExpense	111788000	USD
CY2014	us-gaap	Interest Expense InterestExpense	70960000	USD
CY2015	us-gaap	Interest Expense InterestExpense	83719000	USD
CY2013	us-gaap	Interest Paid Net InterestPaidNet	108361000	USD
CY2014	us-gaap	Interest Paid Net InterestPaidNet	69239000	USD
CY2015	us-gaap	Interest Paid Net InterestPaidNet	77810000	USD
CY2014Q4	us-gaap	Interest Payable Current InterestPayableCurrent	14913000	USD
CY2015Q4	us-gaap	Interest Payable Current InterestPayableCurrent	25762000	USD
CY2014Q4	us-gaap	Inventory Net InventoryNet	91191000	USD
CY2015Q4	us-gaap	Inventory Net InventoryNet	86943000	USD
CY2014Q4	us-gaap	Inventory Raw Materials And Supplies InventoryRawMaterialsAndSupplies	49555000	USD
CY2015Q4	us-gaap	Inventory Raw Materials And Supplies InventoryRawMaterialsAndSupplies	55726000	USD
CY2013	us-gaap	Investment Income Interest InvestmentIncomeInterest	1723000	USD
CY2014	us-gaap	Investment Income Interest InvestmentIncomeInterest	1925000	USD
CY2015	us-gaap	Investment Income Interest InvestmentIncomeInterest	1621000	USD
CY2013	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	7169000	USD
CY2014	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	6932000	USD
CY2015	us-gaap	Lease And Rental Expense LeaseAndRentalExpense	7177000	USD
CY2014Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	4245902000	USD
CY2015Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	4655501000	USD
CY2014Q4	us-gaap	Liabilities Current LiabilitiesCurrent	651281000	USD
CY2015Q4	us-gaap	Liabilities Current LiabilitiesCurrent	422029000	USD
CY2014Q4	us-gaap	Liabilities Noncurrent LiabilitiesNoncurrent	973148000	USD
CY2015Q4	us-gaap	Liabilities Noncurrent LiabilitiesNoncurrent	900739000	USD
CY2012Q4	us-gaap	Liability For Uncertain Tax Positions Noncurrent LiabilityForUncertainTaxPositionsNoncurrent	40683000	USD
CY2013Q4	us-gaap	Liability For Uncertain Tax Positions Noncurrent LiabilityForUncertainTaxPositionsNoncurrent	37631000	USD
CY2014Q4	us-gaap	Liability For Uncertain Tax Positions Noncurrent LiabilityForUncertainTaxPositionsNoncurrent	32192000	USD
CY2015Q4	us-gaap	Liability For Uncertain Tax Positions Noncurrent LiabilityForUncertainTaxPositionsNoncurrent	31986000	USD
CY2014Q4	us-gaap	Long Term Debt LongTermDebt	1542589000	USD
CY2015Q4	us-gaap	Long Term Debt LongTermDebt	1866866000	USD
CY2014Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	275000000	USD
CY2015Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	0	USD
CY2015Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	1368855000	USD
CY2015Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	200000000	USD
CY2015Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	0	USD
CY2015Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	0	USD
CY2015Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	300000000	USD
CY2014Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	1267589000	USD
CY2015Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	1866866000	USD
CY2014Q4	us-gaap	Long Term Investments LongTermInvestments	17294000	USD
CY2015Q4	us-gaap	Long Term Investments LongTermInvestments	11985000	USD
CY2014Q4	us-gaap	Loss Contingency Accrual Carrying Value Current LossContingencyAccrualCarryingValueCurrent	0	USD
CY2015Q4	us-gaap	Loss Contingency Accrual Carrying Value Current LossContingencyAccrualCarryingValueCurrent	38750000	USD
CY2013	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	17028000	USD
CY2014	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	91067000	USD
CY2015	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	483702000	USD
CY2013	us-gaap	Net Cash Provided By Used In Financing Activities Continuing Operations NetCashProvidedByUsedInFinancingActivitiesContinuingOperations	17028000	USD
CY2014	us-gaap	Net Cash Provided By Used In Financing Activities Continuing Operations NetCashProvidedByUsedInFinancingActivitiesContinuingOperations	91067000	USD
CY2015	us-gaap	Net Cash Provided By Used In Financing Activities Continuing Operations NetCashProvidedByUsedInFinancingActivitiesContinuingOperations	483702000	USD
CY2013	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-349278000	USD
CY2014	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-401147000	USD
CY2015	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-476389000	USD
CY2013	us-gaap	Net Cash Provided By Used In Investing Activities Continuing Operations NetCashProvidedByUsedInInvestingActivitiesContinuingOperations	-349278000	USD
CY2014	us-gaap	Net Cash Provided By Used In Investing Activities Continuing Operations NetCashProvidedByUsedInInvestingActivitiesContinuingOperations	-401147000	USD
CY2015	us-gaap	Net Cash Provided By Used In Investing Activities Continuing Operations NetCashProvidedByUsedInInvestingActivitiesContinuingOperations	-476389000	USD
CY2013	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	324629000	USD
CY2014	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	323457000	USD
CY2015	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	428004000	USD
CY2013	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	325513000	USD
CY2014	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	323457000	USD
CY2015	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	428004000	USD
CY2013	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	117423000	USD
CY2014Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	48645000	USD
CY2014Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	20347000	USD
CY2014Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	27363000	USD
CY2014Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	34534000	USD
CY2014	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	130889000	USD
CY2015Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	33850000	USD
CY2015Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-41842000	USD
CY2015Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-9943000	USD
CY2015Q4	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-14176000	USD
CY2015	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-32111000	USD
CY2013	us-gaap	Net Increase Decrease In Sales And Transfer Prices And Production Costs NetIncreaseDecreaseInSalesAndTransferPricesAndProductionCosts	15126000	USD
CY2014	us-gaap	Net Increase Decrease In Sales And Transfer Prices And Production Costs NetIncreaseDecreaseInSalesAndTransferPricesAndProductionCosts	-28544000	USD
CY2015	us-gaap	Net Increase Decrease In Sales And Transfer Prices And Production Costs NetIncreaseDecreaseInSalesAndTransferPricesAndProductionCosts	-127199000	USD
CY2013	us-gaap	Operating Expenses OperatingExpenses	1016407000	USD
CY2014	us-gaap	Operating Expenses OperatingExpenses	1129702000	USD
CY2015	us-gaap	Operating Expenses OperatingExpenses	1274810000	USD
CY2013	us-gaap	Operating Income Loss OperatingIncomeLoss	259445000	USD
CY2014Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	90432000	USD
CY2014Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	47412000	USD
CY2014Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	55238000	USD
CY2014Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	70786000	USD
CY2014	us-gaap	Operating Income Loss OperatingIncomeLoss	263868000	USD
CY2015Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	70500000	USD
CY2015Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	-38858000	USD
CY2015Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	-2044000	USD
CY2015Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	197000	USD
CY2015	us-gaap	Operating Income Loss OperatingIncomeLoss	29795000	USD
CY2015Q4	us-gaap	Operating Leases Future Minimum Payments Due Current OperatingLeasesFutureMinimumPaymentsDueCurrent	2907000	USD
CY2015Q4	us-gaap	Operating Leases Future Minimum Payments Due In Five Years OperatingLeasesFutureMinimumPaymentsDueInFiveYears	1238000	USD
CY2015Q4	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	1932000	USD
CY2015Q4	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	2268000	USD
CY2015Q4	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	2491000	USD
CY2015Q4	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	6199000	USD
CY2014Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	50181000	USD
CY2015Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	38318000	USD
CY2014Q4	us-gaap	Other Assets Current OtherAssetsCurrent	24842000	USD
CY2015Q4	us-gaap	Other Assets Current OtherAssetsCurrent	71763000	USD
CY2014Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	29086000	USD
CY2015Q4	us-gaap	Other Assets Noncurrent OtherAssetsNoncurrent	20566000	USD
CY2013	us-gaap	Other Comprehensive Income Defined Benefit Plan Net Prior Service Costs Credit Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax	406000	USD
CY2014	us-gaap	Other Comprehensive Income Defined Benefit Plan Net Prior Service Costs Credit Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax	-237000	USD
CY2015	us-gaap	Other Comprehensive Income Defined Benefit Plan Net Prior Service Costs Credit Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax	0	USD
CY2013	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	8237000	USD
CY2014	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-10590000	USD
CY2015	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	2657000	USD
CY2013	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	3813000	USD
CY2014	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-5004000	USD
CY2015	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	1375000	USD
CY2013	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	-165000	USD
CY2014	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	-141000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax	-150000	USD
CY2013	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-88000	USD
CY2014	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-76000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-88000	USD
CY2013	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	18066000	USD
CY2014	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	2378000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	5989000	USD
CY2013	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Benefit Plan Improvement Tax Effect OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBenefitPlanImprovementTaxEffect	185000	USD
CY2014	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Benefit Plan Improvement Tax Effect OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBenefitPlanImprovementTaxEffect	-17000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Benefit Plan Improvement Tax Effect OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansBenefitPlanImprovementTaxEffect	0	USD
CY2013	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	-971000	USD
CY2014	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	-348000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	-972000	USD
CY2013	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax	-4046000	USD
CY2014	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax	-3320000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax	6542000	USD
CY2013	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax	-2016000	USD
CY2014	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax	-2344000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax	4271000	USD
CY2013	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-1820000	USD
CY2014	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-646000	USD
CY2015	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-1850000	USD
CY2013	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	4534000	USD
CY2014	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	8906000	USD
CY2015	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	8174000	USD
CY2013	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	2445000	USD
CY2014	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	5239000	USD
CY2015	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	4496000	USD
CY2013	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	1243000	USD
CY2014	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	500000	USD
CY2015	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	7483000	USD
CY2014Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	154406000	USD
CY2015Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	155369000	USD
CY2013	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-9826000	USD
CY2014	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-14415000	USD
CY2015	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	4872000	USD
CY2013	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	694000	USD
CY2014	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	377000	USD
CY2015	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	372000	USD
CY2013	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	1971000	USD
CY2014	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	2065000	USD
CY2015	us-gaap	Other Nonoperating Income OtherNonoperatingIncome	2256000	USD
CY2013	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	1798000	USD
CY2014	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	2681000	USD
CY2015	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	2437000	USD
CY2013	us-gaap	Payments For Derivative Instrument Financing Activities PaymentsForDerivativeInstrumentFinancingActivities	63939000	USD
CY2014	us-gaap	Payments For Derivative Instrument Financing Activities PaymentsForDerivativeInstrumentFinancingActivities	0	USD
CY2015	us-gaap	Payments For Derivative Instrument Financing Activities PaymentsForDerivativeInstrumentFinancingActivities	0	USD
CY2013	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-5471000	USD
CY2014	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	2653000	USD
CY2015	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	-1062000	USD
CY2013	us-gaap	Payments Of Dividends PaymentsOfDividends	67587000	USD
CY2014	us-gaap	Payments Of Dividends PaymentsOfDividends	69636000	USD
CY2015	us-gaap	Payments Of Dividends PaymentsOfDividends	72604000	USD
CY2013	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	0	USD
CY2014	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	0	USD
CY2015	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	21970000	USD
CY2013	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	354749000	USD
CY2014	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	398494000	USD
CY2015	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	455481000	USD
CY2013	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	22194000	USD
CY2014	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	14814000	USD
CY2015	us-gaap	Pension And Other Postretirement Benefit Expense PensionAndOtherPostretirementBenefitExpense	20616000	USD
CY2014Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	158966000	USD
CY2015Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	146459000	USD
CY2013	us-gaap	Pension Contributions PensionContributions	12500000	USD
CY2014	us-gaap	Pension Contributions PensionContributions	10200000	USD
CY2015	us-gaap	Pension Contributions PensionContributions	10200000	USD
CY2015Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	25000000	shares
CY2015Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	0	shares
CY2013	us-gaap	Previously Estimated Development Costs Incurred PreviouslyEstimatedDevelopmentCostsIncurred	3554000	USD
CY2014	us-gaap	Previously Estimated Development Costs Incurred PreviouslyEstimatedDevelopmentCostsIncurred	2079000	USD
CY2015	us-gaap	Previously Estimated Development Costs Incurred PreviouslyEstimatedDevelopmentCostsIncurred	27211000	USD
CY2015Q4	us-gaap	Proceeds From Convertible Debt ProceedsFromConvertibleDebt	299000000	USD
CY2013	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	4354000	USD
CY2014	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	3251000	USD
CY2015	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	248759000	USD
CY2013	us-gaap	Proceeds From Lines Of Credit ProceedsFromLinesOfCredit	337650000	USD
CY2014	us-gaap	Proceeds From Lines Of Credit ProceedsFromLinesOfCredit	396250000	USD
CY2015	us-gaap	Proceeds From Lines Of Credit ProceedsFromLinesOfCredit	397310000	USD
CY2013	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-15394000	USD
CY2014	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	17152000	USD
CY2013	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	800000000	USD
CY2014	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	160000000	USD
CY2015	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	300000000	USD
CY2015	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-9283000	USD
CY2015Q4	us-gaap	Proceeds From Sale Of Interest In Corporate Unit ProceedsFromSaleOfInterestInCorporateUnit	290000000	USD
CY2015Q4	us-gaap	Proceeds From Sale Of Interest In Corporate Unit ProceedsFromSaleOfInterestInCorporateUnit	290030000	USD
CY2013	us-gaap	Proceeds From Sale Of Interest In Corporate Unit ProceedsFromSaleOfInterestInCorporateUnit	0	USD
CY2014	us-gaap	Proceeds From Sale Of Interest In Corporate Unit ProceedsFromSaleOfInterestInCorporateUnit	0	USD
CY2015	us-gaap	Proceeds From Sale Of Interest In Corporate Unit ProceedsFromSaleOfInterestInCorporateUnit	290030000	USD
CY2014Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	4563400000	USD
CY2015Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	4976778000	USD
CY2014	us-gaap	Property Plant And Equipment Gross Period Increase Decrease PropertyPlantAndEquipmentGrossPeriodIncreaseDecrease	391267000	USD
CY2015	us-gaap	Property Plant And Equipment Gross Period Increase Decrease PropertyPlantAndEquipmentGrossPeriodIncreaseDecrease	458821000	USD
CY2014Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	3205471000	USD
CY2015Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	3259094000	USD
CY2015Q4	us-gaap	Proved Developed Reserves Boe1 ProvedDevelopedReservesBOE1	6600000	Mcfe
CY2013	us-gaap	Public Utilities Allowance For Funds Used During Construction Capitalized Cost Of Equity PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity	607000	USD
CY2014	us-gaap	Public Utilities Allowance For Funds Used During Construction Capitalized Cost Of Equity PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity	994000	USD
CY2015	us-gaap	Public Utilities Allowance For Funds Used During Construction Capitalized Cost Of Equity PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedCostOfEquity	897000	USD
CY2014Q4	us-gaap	Regulatory Assets RegulatoryAssets	257839000	USD
CY2015Q4	us-gaap	Regulatory Assets RegulatoryAssets	232484000	USD
CY2014Q4	us-gaap	Regulatory Assets Current RegulatoryAssetsCurrent	74396000	USD
CY2015Q4	us-gaap	Regulatory Assets Current RegulatoryAssetsCurrent	57359000	USD
CY2014Q4	us-gaap	Regulatory Assets Noncurrent RegulatoryAssetsNoncurrent	183443000	USD
CY2015Q4	us-gaap	Regulatory Assets Noncurrent RegulatoryAssetsNoncurrent	175125000	USD
CY2014Q4	us-gaap	Regulatory Liabilities RegulatoryLiabilities	148831000	USD
CY2015Q4	us-gaap	Regulatory Liabilities RegulatoryLiabilities	153041000	USD
CY2014Q4	us-gaap	Regulatory Liability Current RegulatoryLiabilityCurrent	3687000	USD
CY2015Q4	us-gaap	Regulatory Liability Current RegulatoryLiabilityCurrent	4865000	USD
CY2014Q4	us-gaap	Regulatory Liability Noncurrent RegulatoryLiabilityNoncurrent	145144000	USD
CY2015Q4	us-gaap	Regulatory Liability Noncurrent RegulatoryLiabilityNoncurrent	148176000	USD
CY2013	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	532150000	USD
CY2014	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	403750000	USD
CY2015	us-gaap	Repayments Of Lines Of Credit RepaymentsOfLinesOfCredit	395510000	USD
CY2013	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	445906000	USD
CY2014	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	12200000	USD
CY2015	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	275000000	USD
CY2014Q4	us-gaap	Restricted Cash And Investments Current RestrictedCashAndInvestmentsCurrent	2056000	USD
CY2015Q4	us-gaap	Restricted Cash And Investments Current RestrictedCashAndInvestmentsCurrent	1697000	USD
CY2013	us-gaap	Results Of Operations Depreciation Depletion And Amortization And Valuation Provisions ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions	16717000	USD
CY2014	us-gaap	Results Of Operations Depreciation Depletion And Amortization And Valuation Provisions ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions	23288000	USD
CY2015	us-gaap	Results Of Operations Depreciation Depletion And Amortization And Valuation Provisions ResultsOfOperationsDepreciationDepletionAndAmortizationAndValuationProvisions	28062000	USD
CY2013	us-gaap	Results Of Operations Expense From Oil And Gas Producing Activities ResultsOfOperationsExpenseFromOilAndGasProducingActivities	36857000	USD
CY2014	us-gaap	Results Of Operations Expense From Oil And Gas Producing Activities ResultsOfOperationsExpenseFromOilAndGasProducingActivities	45443000	USD
CY2015	us-gaap	Results Of Operations Expense From Oil And Gas Producing Activities ResultsOfOperationsExpenseFromOilAndGasProducingActivities	297432000	USD
CY2013	us-gaap	Results Of Operations Impairment Of Oil And Gas Properties ResultsOfOperationsImpairmentOfOilAndGasProperties	0	USD
CY2014	us-gaap	Results Of Operations Impairment Of Oil And Gas Properties ResultsOfOperationsImpairmentOfOilAndGasProperties	0	USD
CY2015	us-gaap	Results Of Operations Impairment Of Oil And Gas Properties ResultsOfOperationsImpairmentOfOilAndGasProperties	249608000	USD
CY2013	us-gaap	Results Of Operations Income Before Income Taxes ResultsOfOperationsIncomeBeforeIncomeTaxes	18027000	USD
CY2014	us-gaap	Results Of Operations Income Before Income Taxes ResultsOfOperationsIncomeBeforeIncomeTaxes	9671000	USD
CY2015	us-gaap	Results Of Operations Income Before Income Taxes ResultsOfOperationsIncomeBeforeIncomeTaxes	-254149000	USD
CY2013	us-gaap	Results Of Operations Income Tax Expense ResultsOfOperationsIncomeTaxExpense	6308000	USD
CY2014	us-gaap	Results Of Operations Income Tax Expense ResultsOfOperationsIncomeTaxExpense	3415000	USD
CY2015	us-gaap	Results Of Operations Income Tax Expense ResultsOfOperationsIncomeTaxExpense	-93743000	USD
CY2013	us-gaap	Results Of Operations Oil And Gas Producing Activities Net Income Excluding Corporate Overhead And Interest Costs ResultsOfOperationsOilAndGasProducingActivitiesNetIncomeExcludingCorporateOverheadAndInterestCosts	11719000	USD
CY2014	us-gaap	Results Of Operations Oil And Gas Producing Activities Net Income Excluding Corporate Overhead And Interest Costs ResultsOfOperationsOilAndGasProducingActivitiesNetIncomeExcludingCorporateOverheadAndInterestCosts	6256000	USD
CY2015	us-gaap	Results Of Operations Oil And Gas Producing Activities Net Income Excluding Corporate Overhead And Interest Costs ResultsOfOperationsOilAndGasProducingActivitiesNetIncomeExcludingCorporateOverheadAndInterestCosts	-160406000	USD
CY2013	us-gaap	Results Of Operations Production Or Lifting Costs ResultsOfOperationsProductionOrLiftingCosts	20140000	USD
CY2014	us-gaap	Results Of Operations Production Or Lifting Costs ResultsOfOperationsProductionOrLiftingCosts	22155000	USD
CY2015	us-gaap	Results Of Operations Production Or Lifting Costs ResultsOfOperationsProductionOrLiftingCosts	19762000	USD
CY2013	us-gaap	Results Of Operations Revenue From Oil And Gas Producing Activities ResultsOfOperationsRevenueFromOilAndGasProducingActivities	54884000	USD
CY2014	us-gaap	Results Of Operations Revenue From Oil And Gas Producing Activities ResultsOfOperationsRevenueFromOilAndGasProducingActivities	55114000	USD
CY2015	us-gaap	Results Of Operations Revenue From Oil And Gas Producing Activities ResultsOfOperationsRevenueFromOilAndGasProducingActivities	43283000	USD
CY2014Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	577249000	USD
CY2015Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	472534000	USD
CY2013	us-gaap	Revisions Of Previous Quantity Estimates RevisionsOfPreviousQuantityEstimates	12851000	USD
CY2014	us-gaap	Revisions Of Previous Quantity Estimates RevisionsOfPreviousQuantityEstimates	23722000	USD
CY2015	us-gaap	Revisions Of Previous Quantity Estimates RevisionsOfPreviousQuantityEstimates	-6941000	USD
CY2013	us-gaap	Sales And Transfers Of Oil And Gas Produced Net Of Production Costs SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts	35932000	USD
CY2014	us-gaap	Sales And Transfers Of Oil And Gas Produced Net Of Production Costs SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts	32139000	USD
CY2015	us-gaap	Sales And Transfers Of Oil And Gas Produced Net Of Production Costs SalesAndTransfersOfOilAndGasProducedNetOfProductionCosts	29948000	USD
CY2013	us-gaap	Sales Revenue Net SalesRevenueNet	1275852000	USD
CY2014Q1	us-gaap	Sales Revenue Net SalesRevenueNet	460169000	USD
CY2014Q2	us-gaap	Sales Revenue Net SalesRevenueNet	283237000	USD
CY2014Q3	us-gaap	Sales Revenue Net SalesRevenueNet	272087000	USD
CY2014Q4	us-gaap	Sales Revenue Net SalesRevenueNet	378077000	USD
CY2014	us-gaap	Sales Revenue Net SalesRevenueNet	1393570000	USD
CY2015Q1	us-gaap	Sales Revenue Net SalesRevenueNet	441987000	USD
CY2015Q2	us-gaap	Sales Revenue Net SalesRevenueNet	272254000	USD
CY2015Q3	us-gaap	Sales Revenue Net SalesRevenueNet	272105000	USD
CY2015Q4	us-gaap	Sales Revenue Net SalesRevenueNet	318259000	USD
CY2015	us-gaap	Sales Revenue Net SalesRevenueNet	1304605000	USD
CY2013	us-gaap	Share Based Compensation ShareBasedCompensation	12595000	USD
CY2014	us-gaap	Share Based Compensation ShareBasedCompensation	9329000	USD
CY2015	us-gaap	Share Based Compensation ShareBasedCompensation	4076000	USD
CY2015Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	1256747	shares
CY2014Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	75000000	USD
CY2012Q4	us-gaap	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	136103000	USD
CY2013Q4	us-gaap	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	159425000	USD
CY2015Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	76800000	USD
CY2014Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1353884000	USD
CY2015Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1465867000	USD
CY2014Q4	us-gaap	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	183022000	USD
CY2015Q4	us-gaap	Standardized Measure Of Discounted Future Net Cash Flows Relating To Proved Oil And Gas Reserves StandardizedMeasureOfDiscountedFutureNetCashFlowsRelatingToProvedOilAndGasReserves	79028000	USD
CY2013	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	3129000	USD
CY2014	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	2878000	USD
CY2015	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	2957000	USD
CY2015	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	254581000	USD
CY2013	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	5867000	USD
CY2014	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	4415000	USD
CY2015	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	4240000	USD
CY2012Q4	us-gaap	Stockholders Equity StockholdersEquity	1205800000	USD
CY2013Q4	us-gaap	Stockholders Equity StockholdersEquity	1283500000	USD
CY2014Q4	us-gaap	Stockholders Equity StockholdersEquity	1353884000	USD
CY2015Q4	us-gaap	Stockholders Equity StockholdersEquity	1465867000	USD
CY2013	us-gaap	Stockholders Equity Other StockholdersEquityOther	-392000	USD
CY2014	us-gaap	Stockholders Equity Other StockholdersEquityOther	41000	USD
CY2015	us-gaap	Stockholders Equity Other StockholdersEquityOther	25000	USD
CY2013	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	40012000	USD
CY2014	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	43580000	USD
CY2015	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	44353000	USD
CY2014Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	42226	shares
CY2015Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	39720	shares
CY2014Q4	us-gaap	Treasury Stock Value TreasuryStockValue	1875000	USD
CY2015Q4	us-gaap	Treasury Stock Value TreasuryStockValue	1888000	USD
CY2013	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	30169000	USD
CY2014	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	0	USD
CY2015	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	0	USD
CY2013	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	4578000	USD
CY2014	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	6692000	USD
CY2015	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	3491000	USD
CY2013	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	USD
CY2014	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	USD
CY2015	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	USD
CY2014Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	11500000	USD
CY2015Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	13300000	USD
CY2013	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	1600000	USD
CY2014	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	1600000	USD
CY2015	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	1800000	USD
CY2013	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	0	USD
CY2014	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	0	USD
CY2015	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	0	USD
CY2013	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	1526000	USD
CY2014	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	1253000	USD
CY2015	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	3285000	USD
CY2015Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	2600000	USD
CY2015Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On Fifth Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary	48966000	USD
CY2015Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On First Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary	165484000	USD
CY2015Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On Fourth Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary	49196000	USD
CY2015Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On Second Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary	133534000	USD
CY2013	us-gaap	Valuation Allowances And Reserves Adjustments ValuationAllowancesAndReservesAdjustments	0	USD
CY2014	us-gaap	Valuation Allowances And Reserves Adjustments ValuationAllowancesAndReservesAdjustments	0	USD
CY2015	us-gaap	Valuation Allowances And Reserves Adjustments ValuationAllowancesAndReservesAdjustments	0	USD
CY2015Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Balance On Third Anniversary UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary	82703000	USD
CY2015Q4	us-gaap	Unrecorded Unconditional Purchase Obligation Due After Five Years UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears	130745000	USD
CY2013	us-gaap	Utilities Operating Expense Maintenance Operations And Other Costs And Expenses UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses	261919000	USD
CY2014	us-gaap	Utilities Operating Expense Maintenance Operations And Other Costs And Expenses UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses	270954000	USD
CY2015	us-gaap	Utilities Operating Expense Maintenance Operations And Other Costs And Expenses UtilitiesOperatingExpenseMaintenanceOperationsAndOtherCostsAndExpenses	272407000	USD
CY2012Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	768000	USD
CY2013Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	1237000	USD
CY2014Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	1516000	USD
CY2015Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	1741000	USD
CY2013	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	2780000	USD
CY2014	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	4470000	USD
CY2015	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	3860000	USD
CY2013	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	7310000	USD
CY2014	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	8424000	USD
CY2015	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	7767000	USD
CY2013	us-gaap	Valuation Allowances And Reserves Recoveries ValuationAllowancesAndReservesRecoveries	4999000	USD
CY2014	us-gaap	Valuation Allowances And Reserves Recoveries ValuationAllowancesAndReservesRecoveries	4233000	USD
CY2015	us-gaap	Valuation Allowances And Reserves Recoveries ValuationAllowancesAndReservesRecoveries	4132000	USD
CY2013	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	44419000	shares
CY2014	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	44598000	shares
CY2015	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	45288000	shares
CY2013	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	44163000	shares
CY2014	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	44394000	shares
CY2015	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	45288000	shares
CY2015Q4	us-gaap	Wells In Process Of Drilling WellsInProcessOfDrilling	1006
CY2015	us-gaap	Property Plant And Equipment Preproduction Design And Development Costs PropertyPlantAndEquipmentPreproductionDesignAndDevelopmentCosts	<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-weight:bold;">Development Costs</font></div><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;"><br clear="none"/></font></div><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">According to accounting standards for business combinations, we expense, when incurred, development and acquisition costs associated with corporate development activities prior to acquiring or beginning construction of a project. Expensed development costs are included in Other operating expenses on the accompanying Consolidated Statements of Income (Loss).</font></div><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;"><br clear="none"/></font></div></div>
CY2015	us-gaap	Use Of Estimates UseOfEstimates	<div style="font-family:Times New Roman;font-size:10pt;"><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;font-weight:bold;">Use of Estimates and Basis of Presentation</font></div><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;"><br clear="none"/></font></div><div style="line-height:120%;text-align:left;font-size:10pt;"><font style="font-family:inherit;font-size:10pt;">The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of certain assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Changes in facts and circumstances or additional information may result in revised estimates and actual results could differ materially from those estimates.</font></div></div>

Files In Submission

Name	View Source	Status
0001130464-16-000176-index-headers.html	Edgar Link	pending
0001130464-16-000176-index.html	Edgar Link	pending
0001130464-16-000176.txt	Edgar Link	pending
0001130464-16-000176-xbrl.zip	Edgar Link	pending
bkh-20151231.xml	Edgar Link	completed
bkh-20151231.xsd	Edgar Link	pending
bkh-20151231_cal.xml	Edgar Link	unprocessable
bkh-20151231_def.xml	Edgar Link	unprocessable
bkh-20151231_lab.xml	Edgar Link	unprocessable
bkh-20151231_pre.xml	Edgar Link	unprocessable
bkh10k122015.htm	Edgar Link	pending
bkhex-1010formofrestricted.htm	Edgar Link	pending
bkhex-1012formofrestricted.htm	Edgar Link	pending
bkhex-108stockoptionawarda.htm	Edgar Link	pending
bkhex-21listofsubs122015.htm	Edgar Link	pending
bkhex-221stamdpurchasesale.htm	Edgar Link	pending
bkhex-231auditconsent122015.htm	Edgar Link	pending
bkhex-232engineersconsent1.htm	Edgar Link	pending
bkhex-311ceo122015.htm	Edgar Link	pending
bkhex-312cfo122015.htm	Edgar Link	pending
bkhex-321ceo122015.htm	Edgar Link	pending
bkhex-322cfo122015.htm	Edgar Link	pending
bkhex-95minesafetydata1220.htm	Edgar Link	pending
bkhex-99oilandgas122015.htm	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
R100.htm	Edgar Link	pending
R101.htm	Edgar Link	pending
R102.htm	Edgar Link	pending
R103.htm	Edgar Link	pending
R104.htm	Edgar Link	pending
R105.htm	Edgar Link	pending
R106.htm	Edgar Link	pending
R107.htm	Edgar Link	pending
R108.htm	Edgar Link	pending
R109.htm	Edgar Link	pending
R11.htm	Edgar Link	pending
R110.htm	Edgar Link	pending
R111.htm	Edgar Link	pending
R112.htm	Edgar Link	pending
R113.htm	Edgar Link	pending
R114.htm	Edgar Link	pending
R115.htm	Edgar Link	pending
R116.htm	Edgar Link	pending
R117.htm	Edgar Link	pending
R118.htm	Edgar Link	pending
R119.htm	Edgar Link	pending
R12.htm	Edgar Link	pending
R120.htm	Edgar Link	pending
R121.htm	Edgar Link	pending
R122.htm	Edgar Link	pending
R123.htm	Edgar Link	pending
R124.htm	Edgar Link	pending
R125.htm	Edgar Link	pending
R126.htm	Edgar Link	pending
R127.htm	Edgar Link	pending
R128.htm	Edgar Link	pending
R129.htm	Edgar Link	pending
R13.htm	Edgar Link	pending
R130.htm	Edgar Link	pending
R131.htm	Edgar Link	pending
R132.htm	Edgar Link	pending
R133.htm	Edgar Link	pending
R134.htm	Edgar Link	pending
R135.htm	Edgar Link	pending
R136.htm	Edgar Link	pending
R137.htm	Edgar Link	pending
R138.htm	Edgar Link	pending
R139.htm	Edgar Link	pending
R14.htm	Edgar Link	pending
R140.htm	Edgar Link	pending
R141.htm	Edgar Link	pending
R142.htm	Edgar Link	pending
R143.htm	Edgar Link	pending
R144.htm	Edgar Link	pending
R145.htm	Edgar Link	pending
R146.htm	Edgar Link	pending
R15.htm	Edgar Link	pending
R16.htm	Edgar Link	pending
R17.htm	Edgar Link	pending
R18.htm	Edgar Link	pending
R19.htm	Edgar Link	pending
R2.htm	Edgar Link	pending
R20.htm	Edgar Link	pending
R21.htm	Edgar Link	pending
R22.htm	Edgar Link	pending
R23.htm	Edgar Link	pending
R24.htm	Edgar Link	pending
R25.htm	Edgar Link	pending
R26.htm	Edgar Link	pending
R27.htm	Edgar Link	pending
R28.htm	Edgar Link	pending
R29.htm	Edgar Link	pending
R3.htm	Edgar Link	pending
R30.htm	Edgar Link	pending
R31.htm	Edgar Link	pending
R32.htm	Edgar Link	pending
R33.htm	Edgar Link	pending
R34.htm	Edgar Link	pending
R35.htm	Edgar Link	pending
R36.htm	Edgar Link	pending
R37.htm	Edgar Link	pending
R38.htm	Edgar Link	pending
R39.htm	Edgar Link	pending
R4.htm	Edgar Link	pending
R40.htm	Edgar Link	pending
R41.htm	Edgar Link	pending
R42.htm	Edgar Link	pending
R43.htm	Edgar Link	pending
R44.htm	Edgar Link	pending
R45.htm	Edgar Link	pending
R46.htm	Edgar Link	pending
R47.htm	Edgar Link	pending
R48.htm	Edgar Link	pending
R49.htm	Edgar Link	pending
R5.htm	Edgar Link	pending
R50.htm	Edgar Link	pending
R51.htm	Edgar Link	pending
R52.htm	Edgar Link	pending
R53.htm	Edgar Link	pending
R54.htm	Edgar Link	pending
R55.htm	Edgar Link	pending
R56.htm	Edgar Link	pending
R57.htm	Edgar Link	pending
R58.htm	Edgar Link	pending
R59.htm	Edgar Link	pending
R6.htm	Edgar Link	pending
R60.htm	Edgar Link	pending
R61.htm	Edgar Link	pending
R62.htm	Edgar Link	pending
R63.htm	Edgar Link	pending
R64.htm	Edgar Link	pending
R65.htm	Edgar Link	pending
R66.htm	Edgar Link	pending
R67.htm	Edgar Link	pending
R68.htm	Edgar Link	pending
R69.htm	Edgar Link	pending
R7.htm	Edgar Link	pending
R70.htm	Edgar Link	pending
R71.htm	Edgar Link	pending
R72.htm	Edgar Link	pending
R73.htm	Edgar Link	pending
R74.htm	Edgar Link	pending
R75.htm	Edgar Link	pending
R76.htm	Edgar Link	pending
R77.htm	Edgar Link	pending
R78.htm	Edgar Link	pending
R79.htm	Edgar Link	pending
R8.htm	Edgar Link	pending
R80.htm	Edgar Link	pending
R81.htm	Edgar Link	pending
R82.htm	Edgar Link	pending
R83.htm	Edgar Link	pending
R84.htm	Edgar Link	pending
R85.htm	Edgar Link	pending
R86.htm	Edgar Link	pending
R87.htm	Edgar Link	pending
R88.htm	Edgar Link	pending
R89.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
R90.htm	Edgar Link	pending
R91.htm	Edgar Link	pending
R92.htm	Edgar Link	pending
R93.htm	Edgar Link	pending
R94.htm	Edgar Link	pending
R95.htm	Edgar Link	pending
R96.htm	Edgar Link	pending
R97.htm	Edgar Link	pending
R98.htm	Edgar Link	pending
R99.htm	Edgar Link	pending
report.css	Edgar Link	pending
Show.js	Edgar Link	pending

Create your account

Find Stocks Worth Researching

Deeply Understand Businesses

Value Businesses Intelligently

$BKH
BLACK HILLS CORP /SD/ Stock $bkh

2014 Q4 Form 10-K Financial Statement

#000113046416000176 Filed on February 25, 2016

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$BKH BLACK HILLS CORP /SD/ Stock $bkh

2014 Q4 Form 10-K Financial Statement

#000113046416000176 Filed on February 25, 2016

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$BKH
BLACK HILLS CORP /SD/ Stock $bkh