$CPK
CHESAPEAKE UTILITIES CORP Stock $cpk

$cpk Overview Financials Valuation SEC Filings Company Website

2019 Form 10-K Financial Statement

#000162828020002321 Filed on February 26, 2020

Income Statement

Concept	2019	2018 Q4	2018 Q3
Revenue	$479.6M	$134.2M	$93.40M
YoY Change	-2.18%	-25.6%	-26.42%
Cost Of Revenue	$154.5M	$51.20M	$31.00M
YoY Change	-18.77%	-51.42%	-53.66%
Gross Profit	$325.1M	$83.00M	$62.40M
YoY Change	8.33%	10.67%	4.0%
Gross Profit Margin	67.78%	61.84%	66.81%
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$45.42M	$10.60M	$10.63M
YoY Change	12.94%	13.98%	13.58%
% of Gross Profit	13.97%	12.77%	17.04%
Operating Expenses	$373.3M	$54.10M	$80.52M
YoY Change	-5.6%	5.25%	-28.3%
Operating Profit	$106.3M	$28.87M	$12.88M
YoY Change	12.06%	22.2%	-11.98%
Interest Expense	$22.22M	-$4.400M	$4.357M
YoY Change	37.64%	25.71%	31.2%
% of Operating Profit	20.91%	-15.24%	33.83%
Other Income/Expense, Net	-$1.847M	-$400.0K	-$4.000K
YoY Change	204.28%	-20.0%	-97.4%
Pretax Income	$82.21M	$24.10M	$8.518M
YoY Change	5.28%	22.96%	-23.65%
Income Tax	$21.11M	$6.300M	$2.428M
% Of Pretax Income	25.68%	26.14%	28.5%
Net Earnings	$65.15M	$17.80M	$5.538M
YoY Change	15.15%	-31.8%	-18.95%
Net Earnings / Revenue	13.58%	13.26%	5.93%
Basic Earnings Per Share	$3.97	$1.09	$0.34
Diluted Earnings Per Share	$3.96	$1.09	$0.33
COMMON SHARES
Basic Shares Outstanding	16.40M shares	16.38M shares	16.38M shares
Diluted Shares Outstanding	16.45M shares		16.43M shares

Balance Sheet

Concept	2019	2018 Q4	2018 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments	$7.000M	$6.100M	$6.200M
YoY Change	14.75%	8.93%	82.35%
Cash & Equivalents	$7.000M	$6.089M	$6.215M
Short-Term Investments
Other Short-Term Assets	$21.90M	$5.682M	$2.557M
YoY Change	-35.01%	-21.74%	-46.7%
Inventory	$15.40M	$23.50M	$19.20M
Prepaid Expenses		$10.08M	$9.775M
Receivables	$70.40M	$53.84M	$52.66M
Other Receivables	$20.10M	$15.30M	$8.700M
Total Short-Term Assets	$134.8M	$191.5M	$129.0M
YoY Change	-29.61%	7.25%	-13.45%
LONG-TERM ASSETS
Property, Plant & Equipment	$1.475B	$1.354B	$1.263B
YoY Change	6.6%	20.2%	16.37%
Goodwill		$21.57M	$19.60M
YoY Change		10.02%	-10.66%
Intangibles		$3.850M	$4.073M
YoY Change		-17.84%	-11.61%
Long-Term Investments	$9.200M	$6.700M	$8.000M
YoY Change	37.31%	-1.47%	25.0%
Other Assets	$73.40M	$72.40M	$76.30M
YoY Change	1.38%	-4.23%	0.66%
Total Long-Term Assets	$1.648B	$1.502B	$1.377B
YoY Change	9.73%	21.5%	14.93%
TOTAL ASSETS
Total Short-Term Assets	$134.8M	$191.5M	$129.0M
Total Long-Term Assets	$1.648B	$1.502B	$1.377B
Total Assets	$1.783B	$1.694B	$1.506B
YoY Change	5.28%	19.7%	11.79%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$54.10M	$98.68M	$60.23M
YoY Change	-58.32%	32.12%	13.03%
Accrued Expenses	$30.90M	$29.10M	$29.20M
YoY Change	6.19%	15.94%	12.74%
Deferred Revenue		$480.0K	$583.0K
YoY Change		17.94%
Short-Term Debt	$247.4M	$294.5M	$268.3M
YoY Change	-15.99%	17.35%	32.1%
Long-Term Debt Due	$45.60M	$11.94M	$9.613M
YoY Change	283.19%	26.69%	-20.79%
Total Short-Term Liabilities	$423.3M	$528.2M	$427.1M
YoY Change	-19.86%	27.9%	25.9%
LONG-TERM LIABILITIES
Long-Term Debt	$440.2M	$316.0M	$241.6M
YoY Change	39.3%	60.1%	20.05%
Other Long-Term Liabilities	$177.5M	$2.968M	$3.089M
YoY Change	1.89%	-14.1%	-54.46%
Total Long-Term Liabilities	$617.7M	$319.0M	$244.7M
YoY Change	26.01%	58.82%	17.62%
TOTAL LIABILITIES
Total Short-Term Liabilities	$423.3M	$528.2M	$427.1M
Total Long-Term Liabilities	$617.7M	$319.0M	$244.7M
Total Liabilities	$1.222B	$847.2M	$671.8M
YoY Change	3.95%	38.02%	22.75%
SHAREHOLDERS EQUITY
Retained Earnings		$261.5M	$249.8M
YoY Change		14.13%	19.87%
Common Stock		$263.6M	$263.5M
YoY Change		0.84%	1.08%
Preferred Stock
YoY Change
Treasury Stock (at cost)		$3.854M	$3.818M
YoY Change		13.52%	13.43%
Treasury Stock Shares
Shareholders Equity	$561.6M	$518.4M	$508.3M
YoY Change
Total Liabilities & Shareholders Equity	$1.783B	$1.694B	$1.506B
YoY Change	5.28%	19.7%	11.79%

Cashflow Statement

Concept	2019	2018 Q4	2018 Q3
OPERATING ACTIVITIES
Net Income	$65.15M	$17.80M	$5.538M
YoY Change	15.15%	-31.8%	-18.95%
Depreciation, Depletion And Amortization	$45.42M	$10.60M	$10.63M
YoY Change	12.94%	13.98%	13.58%
Cash From Operating Activities	$103.0M	-$10.60M	$19.60M
YoY Change	-12.27%	-190.6%	880.0%
INVESTING ACTIVITIES
Capital Expenditures	$184.7M	-$69.00M	-$44.60M
YoY Change	-23.14%	52.65%	7.47%
Acquisitions
YoY Change
Other Investing Activities	-$1.900M	-$16.70M	$0.00
YoY Change	-88.48%	5466.67%	-100.0%
Cash From Investing Activities	-$186.6M	-$85.60M	-$44.50M
YoY Change	-27.36%	88.55%	-15.88%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net	$721.0K
YoY Change	2.12%
Debt Paid & Issued, Net	$41.94M
YoY Change	21.95%
Cash From Financing Activities	$84.52M	96.20M	26.60M
YoY Change	-39.61%	167.97%	-48.75%
NET CHANGE
Cash From Operating Activities	$103.0M	-10.60M	19.60M
Cash From Investing Activities	-$186.6M	-85.60M	-44.50M
Cash From Financing Activities	$84.52M	96.20M	26.60M
Net Change In Cash	$896.0K	-0.00000002049	1.700M
YoY Change	88.63%	-100.0%	70.0%
FREE CASH FLOW
Cash From Operating Activities	$103.0M	-$10.60M	$19.60M
Capital Expenditures	$184.7M	-$69.00M	-$44.60M
Free Cash Flow	-$81.76M	$58.40M	$64.20M
YoY Change	-33.52%	2.64%	47.59%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2018Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	1058000	USD
CY2019Q4	us-gaap	Allowance For Doubtful Accounts Receivable Current AllowanceForDoubtfulAccountsReceivableCurrent	1337000	USD
CY2019	dei	Security Exchange Name SecurityExchangeName	NYSE
CY2019	dei	Trading Symbol TradingSymbol	CPK
CY2019	cpk	Maximum Days To Make Default Good MaximumDaysToMakeDefaultGood	P5D
CY2019	dei	Amendment Flag AmendmentFlag	false
CY2019	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2019	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2019	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2019
CY2019	dei	Document Period End Date DocumentPeriodEndDate	2019-12-31
CY2019	dei	Document Type DocumentType	10-K
CY2019	dei	Entity Central Index Key EntityCentralIndexKey	0000019745
CY2019	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2019	dei	Entity Registrant Name EntityRegistrantName	CHESAPEAKE UTILITIES CORP
CY2018Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.4867
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.4867
CY2018Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	50000000	shares
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	50000000	shares
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	1153466	USD
CY2019	us-gaap	Intercompany Agreements Description IntercompanyAgreementsDescription	P3Y
CY2017	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-31000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-22000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Amortization Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Tax OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	-20000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	-432000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	49000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	-368000	USD
CY2017	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	-8000	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	-555000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	-176000	USD
CY2018Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2018Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	2000000	shares
CY2019Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	2000000	shares
CY2019	dei	Document Annual Report DocumentAnnualReport	true
CY2019	dei	Document Transition Report DocumentTransitionReport	false
CY2019	dei	Entity File Number EntityFileNumber	001-11590
CY2019	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	51-0064146
CY2019	dei	Entity Address Address Line1 EntityAddressAddressLine1	909 Silver Lake Boulevard
CY2019	dei	Entity Address City Or Town EntityAddressCityOrTown	Dover
CY2019	dei	Entity Address State Or Province EntityAddressStateOrProvince	DE
CY2019	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	19904
CY2019	dei	City Area Code CityAreaCode	302
CY2019	dei	Local Phone Number LocalPhoneNumber	734-6799
CY2019	dei	Security12b Title Security12bTitle	Common Stock—par value per share $0.4867
CY2019	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2019	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2019	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2019	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2019	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2019	dei	Entity Small Business EntitySmallBusiness	false
CY2019	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2019	dei	Entity Shell Company EntityShellCompany	false
CY2019Q2	dei	Entity Public Float EntityPublicFloat	1500000000	USD
CY2020Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	16407017	shares
CY2019	us-gaap	Regulated Operating Revenue RegulatedOperatingRevenue	343006000	USD
CY2019	us-gaap	Operating Expenses OperatingExpenses	373317000	USD
CY2017	us-gaap	Operating Income Loss OperatingIncomeLoss	89730000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-1830000	USD
CY2018	us-gaap	Regulated Operating Revenue RegulatedOperatingRevenue	345281000	USD
CY2017	us-gaap	Regulated Operating Revenue RegulatedOperatingRevenue	326310000	USD
CY2019	us-gaap	Unregulated Operating Revenue UnregulatedOperatingRevenue	154150000	USD
CY2018	us-gaap	Unregulated Operating Revenue UnregulatedOperatingRevenue	161904000	USD
CY2017	us-gaap	Unregulated Operating Revenue UnregulatedOperatingRevenue	140076000	USD
CY2019	cpk	Other Operating Revenue OtherOperatingRevenue	-17552000	USD
CY2018	cpk	Other Operating Revenue OtherOperatingRevenue	-16869000	USD
CY2017	cpk	Other Operating Revenue OtherOperatingRevenue	-16740000	USD
CY2019	us-gaap	Revenues Revenues	479604000	USD
CY2018	us-gaap	Revenues Revenues	490316000	USD
CY2017	us-gaap	Revenues Revenues	449646000	USD
CY2019	cpk	Regulated Energy Cost Of Sales RegulatedEnergyCostOfSales	102803000	USD
CY2018	cpk	Regulated Energy Cost Of Sales RegulatedEnergyCostOfSales	121828000	USD
CY2017	cpk	Regulated Energy Cost Of Sales RegulatedEnergyCostOfSales	118769000	USD
CY2019	cpk	Unregulated Energy And Other Cost Of Sales UnregulatedEnergyAndOtherCostOfSales	51697000	USD
CY2018	cpk	Unregulated Energy And Other Cost Of Sales UnregulatedEnergyAndOtherCostOfSales	68342000	USD
CY2017	cpk	Unregulated Energy And Other Cost Of Sales UnregulatedEnergyAndOtherCostOfSales	53420000	USD
CY2019	cpk	Operations Operations	137844000	USD
CY2018	cpk	Operations Operations	132523000	USD
CY2017	cpk	Operations Operations	121949000	USD
CY2019	us-gaap	Cost Maintenance CostMaintenance	15679000	USD
CY2018	us-gaap	Cost Maintenance CostMaintenance	14387000	USD
CY2017	us-gaap	Cost Maintenance CostMaintenance	12701000	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	-130000	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	-130000	USD
CY2017	us-gaap	Asset Impairment Charges AssetImpairmentCharges	-130000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	45423000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	40220000	USD
CY2017	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	36386000	USD
CY2019	us-gaap	Taxes Other TaxesOther	20001000	USD
CY2018	us-gaap	Taxes Other TaxesOther	18303000	USD
CY2017	us-gaap	Taxes Other TaxesOther	16821000	USD
CY2018	us-gaap	Operating Expenses OperatingExpenses	395473000	USD
CY2017	us-gaap	Operating Expenses OperatingExpenses	359916000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	106287000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	94843000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-603000	USD
CY2017	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	16383352	shares
CY2019	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	3.73
CY2018	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	3.48
CY2017	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	3.69
CY2019	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	0.24
CY2017	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-2204000	USD
CY2019	us-gaap	Interest Expense InterestExpense	22224000	USD
CY2018	us-gaap	Interest Expense InterestExpense	16146000	USD
CY2017	us-gaap	Interest Expense InterestExpense	12530000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	82233000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	78094000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	74996000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21091000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21232000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14670000	USD
CY2019	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	61142000	USD
CY2018	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	56862000	USD
CY2017	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	60326000	USD
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-1391000	USD
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-282000	USD
CY2017	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-2202000	USD
CY2019	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax	5402000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	65153000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	56580000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	58124000	USD
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16398443	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16369616	shares
CY2017	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16336789	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	16448486	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	16419870	shares
CY2018	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	-0.02
CY2017	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	-0.13
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.97
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.46
CY2017	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.56
CY2019	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	3.72
CY2018	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	3.47
CY2017	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	3.68
CY2019	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Diluted Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare	0.24
CY2018	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Diluted Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare	-0.02
CY2017	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax Per Diluted Share DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTaxPerDilutedShare	-0.13
CY2019	us-gaap	Income Tax Reconciliation Change In Enacted Tax Rate IncomeTaxReconciliationChangeInEnactedTaxRate	0	USD
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.96
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.45
CY2017	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.55
CY2019	us-gaap	Net Income Loss NetIncomeLoss	65153000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	56580000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	58124000	USD
CY2019Q4	cpk	Accrued Revenue AccruedRevenue	20846000	USD
CY2018Q4	cpk	Accrued Revenue AccruedRevenue	22640000	USD
CY2018Q4	us-gaap	Energy Related Inventory Propane Gas EnergyRelatedInventoryPropaneGas	9791000	USD
CY2019Q4	us-gaap	Energy Related Inventory Propane Gas EnergyRelatedInventoryPropaneGas	5824000	USD
CY2018Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	53837000	USD
CY2019Q4	us-gaap	Other Inventory OtherInventory	6067000	USD
CY2018Q4	us-gaap	Other Inventory OtherInventory	7127000	USD
CY2019Q4	us-gaap	Regulatory Assets Current RegulatoryAssetsCurrent	5144000	USD
CY2019	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	-57000	USD
CY2018	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	-55000	USD
CY2017	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	-46000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-1052000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	108000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-663000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-434000	USD
CY2018	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-1371000	USD
CY2017	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-11000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	561000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-1534000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	606000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	65714000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	55046000	USD
CY2017	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	58730000	USD
CY2019Q4	us-gaap	Public Utilities Property Plant And Equipment Plant In Service PublicUtilitiesPropertyPlantAndEquipmentPlantInService	1441473000	USD
CY2018Q4	us-gaap	Public Utilities Property Plant And Equipment Plant In Service PublicUtilitiesPropertyPlantAndEquipmentPlantInService	1297416000	USD
CY2019Q4	cpk	Unregulated Energy Property Plant And Equipment UnregulatedEnergyPropertyPlantAndEquipment	265209000	USD
CY2018Q4	cpk	Unregulated Energy Property Plant And Equipment UnregulatedEnergyPropertyPlantAndEquipment	236440000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Other PropertyPlantAndEquipmentOther	39850000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Other PropertyPlantAndEquipmentOther	34585000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1746532000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1568441000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	336876000	USD
CY2018Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	294089000	USD
CY2019Q4	us-gaap	Construction In Progress Gross ConstructionInProgressGross	54141000	USD
CY2018Q4	us-gaap	Construction In Progress Gross ConstructionInProgressGross	79168000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	1463797000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	1353520000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	6985000	USD
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	6089000	USD
CY2019Q4	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	49562000	USD
CY2018Q4	us-gaap	Regulatory Assets Current RegulatoryAssetsCurrent	4796000	USD
CY2019Q4	us-gaap	Treasury Stock Value TreasuryStockValue	4543000	USD
CY2018Q4	us-gaap	Treasury Stock Value TreasuryStockValue	3854000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	561577000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	518439000	USD
CY2019Q4	us-gaap	Energy Related Inventory Natural Gas In Storage EnergyRelatedInventoryNaturalGasInStorage	3541000	USD
CY2018Q4	us-gaap	Energy Related Inventory Natural Gas In Storage EnergyRelatedInventoryNaturalGasInStorage	3433000	USD
CY2019Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	20050000	USD
CY2018Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	15300000	USD
CY2019Q4	us-gaap	Prepaid Expense Current PrepaidExpenseCurrent	13928000	USD
CY2018Q4	us-gaap	Prepaid Expense Current PrepaidExpenseCurrent	10079000	USD
CY2019Q4	us-gaap	Energy Marketing Contracts Assets Current EnergyMarketingContractsAssetsCurrent	0	USD
CY2018Q4	us-gaap	Energy Marketing Contracts Assets Current EnergyMarketingContractsAssetsCurrent	82000	USD
CY2019Q4	us-gaap	Other Assets Current OtherAssetsCurrent	2879000	USD
CY2018Q4	us-gaap	Other Assets Current OtherAssetsCurrent	5682000	USD
CY2019Q4	us-gaap	Assets Of Disposal Group Including Discontinued Operation Current AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent	0	USD
CY2018Q4	us-gaap	Assets Of Disposal Group Including Discontinued Operation Current AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent	52681000	USD
CY2019Q4	us-gaap	Assets Current AssetsCurrent	134826000	USD
CY2018Q4	us-gaap	Assets Current AssetsCurrent	191537000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	32668000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	21568000	USD
CY2019Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	8129000	USD
CY2018Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	3850000	USD
CY2019Q4	us-gaap	Investments Fair Value Disclosure InvestmentsFairValueDisclosure	9229000	USD
CY2018Q4	us-gaap	Investments Fair Value Disclosure InvestmentsFairValueDisclosure	6711000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	11563000	USD
CY2019Q4	us-gaap	Regulatory Assets Noncurrent RegulatoryAssetsNoncurrent	73407000	USD
CY2018Q4	us-gaap	Regulatory Assets Noncurrent RegulatoryAssetsNoncurrent	72422000	USD
CY2019Q4	cpk	Receivables And Other Deferred Charges ReceivablesAndOtherDeferredCharges	49579000	USD
CY2018Q4	cpk	Receivables And Other Deferred Charges ReceivablesAndOtherDeferredCharges	36401000	USD
CY2019Q4	us-gaap	Disposal Group Including Discontinued Operation Assets Noncurrent DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent	0	USD
CY2018Q4	us-gaap	Disposal Group Including Discontinued Operation Assets Noncurrent DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent	7662000	USD
CY2019Q4	cpk	Deferred Charges And Other Assets DeferredChargesAndOtherAssets	184575000	USD
CY2018Q4	cpk	Deferred Charges And Other Assets DeferredChargesAndOtherAssets	148614000	USD
CY2019Q4	us-gaap	Assets Assets	1783198000	USD
CY2018Q4	us-gaap	Assets Assets	1693671000	USD
CY2019Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2018Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2019Q4	us-gaap	Common Stock Value CommonStockValue	7984000	USD
CY2018Q4	us-gaap	Common Stock Value CommonStockValue	7971000	USD
CY2019Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	259253000	USD
CY2018Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	255651000	USD
CY2019Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	300607000	USD
CY2018Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	261530000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-6267000	USD
CY2018Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-6713000	USD
CY2019Q4	us-gaap	Compensation And Benefits Trust CompensationAndBenefitsTrust	4543000	USD
CY2018Q4	us-gaap	Compensation And Benefits Trust CompensationAndBenefitsTrust	3854000	USD
CY2019Q4	cpk	Longterm Debtand Capital Lease Obligations Netof Current Maturities LongtermDebtandCapitalLeaseObligationsNetofCurrentMaturities	440168000	USD
CY2018Q4	cpk	Longterm Debtand Capital Lease Obligations Netof Current Maturities LongtermDebtandCapitalLeaseObligationsNetofCurrentMaturities	316020000	USD
CY2019Q4	us-gaap	Capitalization Longterm Debt And Equity CapitalizationLongtermDebtAndEquity	1001745000	USD
CY2018Q4	us-gaap	Capitalization Longterm Debt And Equity CapitalizationLongtermDebtAndEquity	834459000	USD
CY2019Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	45600000	USD
CY2018Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	11935000	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	247371000	USD
CY2018Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	294458000	USD
CY2019Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	54068000	USD
CY2018Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	98681000	USD
CY2019Q4	us-gaap	Customer Advances And Deposits Current CustomerAdvancesAndDepositsCurrent	30939000	USD
CY2018Q4	us-gaap	Customer Advances And Deposits Current CustomerAdvancesAndDepositsCurrent	32620000	USD
CY2019Q4	us-gaap	Interest Payable Current InterestPayableCurrent	2554000	USD
CY2018Q4	us-gaap	Interest Payable Current InterestPayableCurrent	2317000	USD
CY2019Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	6644000	USD
CY2018Q4	us-gaap	Dividends Payable Current DividendsPayableCurrent	6060000	USD
CY2019Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	16236000	USD
CY2018Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	13923000	USD
CY2019Q4	us-gaap	Regulatory Liability Current RegulatoryLiabilityCurrent	5991000	USD
CY2018Q4	us-gaap	Regulatory Liability Current RegulatoryLiabilityCurrent	7883000	USD
CY2019Q4	us-gaap	Energy Marketing Contract Liabilities Current EnergyMarketingContractLiabilitiesCurrent	1844000	USD
CY2018Q4	us-gaap	Energy Marketing Contract Liabilities Current EnergyMarketingContractLiabilitiesCurrent	1604000	USD
CY2019Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	12077000	USD
CY2018Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	10081000	USD
CY2018Q4	us-gaap	Liabilities Of Disposal Group Including Discontinued Operation LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation	48672000	USD
CY2019Q4	us-gaap	Liabilities Current LiabilitiesCurrent	423324000	USD
CY2018Q4	us-gaap	Liabilities Current LiabilitiesCurrent	528234000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	180656000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Noncurrent DeferredTaxLiabilitiesNoncurrent	156820000	USD
CY2019Q4	us-gaap	Regulatory Liability Noncurrent RegulatoryLiabilityNoncurrent	127744000	USD
CY2018Q4	us-gaap	Regulatory Liability Noncurrent RegulatoryLiabilityNoncurrent	135039000	USD
CY2019Q4	us-gaap	Accrued Environmental Loss Contingencies Noncurrent AccruedEnvironmentalLossContingenciesNoncurrent	6468000	USD
CY2018Q4	us-gaap	Accrued Environmental Loss Contingencies Noncurrent AccruedEnvironmentalLossContingenciesNoncurrent	7638000	USD
CY2019Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	30569000	USD
CY2018Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	28513000	USD
CY2019Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	9896000	USD
CY2019Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	2796000	USD
CY2018Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	2968000	USD
CY2019Q4	us-gaap	Deferred Credits And Other Liabilities DeferredCreditsAndOtherLiabilities	358129000	USD
CY2018Q4	us-gaap	Deferred Credits And Other Liabilities DeferredCreditsAndOtherLiabilities	330978000	USD
CY2019Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2018Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1693671000	USD
CY2017	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-11085000	USD
CY2018Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2019Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	1783198000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	56580000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	58124000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	65153000	USD
CY2018	cpk	Depreciation And Accretion Included In Other Costs DepreciationAndAccretionIncludedInOtherCosts	8535000	USD
CY2019	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-24476000	USD
CY2018	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-21226000	USD
CY2017	cpk	Depreciation And Accretion Included In Other Costs DepreciationAndAccretionIncludedInOtherCosts	8122000	USD
CY2019	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	45900000	USD
CY2018	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	40802000	USD
CY2017	us-gaap	Other Depreciation And Amortization OtherDepreciationAndAmortization	36599000	USD
CY2019	cpk	Depreciation And Accretion Included In Other Costs DepreciationAndAccretionIncludedInOtherCosts	8752000	USD
CY2018	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	-5497000	USD
CY2017	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	-3179000	USD
CY2019	us-gaap	Unrealized Gain Loss On Commodity Contracts UnrealizedGainLossOnCommodityContracts	1595000	USD
CY2018	us-gaap	Unrealized Gain Loss On Commodity Contracts UnrealizedGainLossOnCommodityContracts	-429000	USD
CY2017	us-gaap	Unrealized Gain Loss On Commodity Contracts UnrealizedGainLossOnCommodityContracts	1001000	USD
CY2019	us-gaap	Employee Benefits And Share Based Compensation EmployeeBenefitsAndShareBasedCompensation	1985000	USD
CY2018	us-gaap	Employee Benefits And Share Based Compensation EmployeeBenefitsAndShareBasedCompensation	856000	USD
CY2017	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	9036000	USD
CY2019	us-gaap	Increase Decrease In Regulatory Assets And Liabilities IncreaseDecreaseInRegulatoryAssetsAndLiabilities	7812000	USD
CY2019	us-gaap	Discontinued Operation Gain Loss From Disposal Of Discontinued Operation Before Income Tax DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax	7344000	USD
CY2019	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	4135000	USD
CY2017	us-gaap	Employee Benefits And Share Based Compensation EmployeeBenefitsAndShareBasedCompensation	1577000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	4279000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	2813000	USD
CY2017	us-gaap	Share Based Compensation ShareBasedCompensation	2490000	USD
CY2019	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	0	USD
CY2018	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	0	USD
CY2017	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	750000	USD
CY2019	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	-36489000	USD
CY2018	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	16311000	USD
CY2017	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	19506000	USD
CY2019	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-8227000	USD
CY2018	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-2107000	USD
CY2018	us-gaap	Increase Decrease In Regulatory Assets And Liabilities IncreaseDecreaseInRegulatoryAssetsAndLiabilities	-2250000	USD
CY2017	us-gaap	Increase Decrease In Regulatory Assets And Liabilities IncreaseDecreaseInRegulatoryAssetsAndLiabilities	2855000	USD
CY2019	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-11115000	USD
CY2018	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	7421000	USD
CY2017	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	7001000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-62021000	USD
CY2018	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	35907000	USD
CY2017	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	15596000	USD
CY2019	us-gaap	Increase Decrease In Income Taxes Receivable IncreaseDecreaseInIncomeTaxesReceivable	4750000	USD
CY2018	us-gaap	Increase Decrease In Income Taxes Receivable IncreaseDecreaseInIncomeTaxesReceivable	522000	USD
CY2017	us-gaap	Increase Decrease In Income Taxes Receivable IncreaseDecreaseInIncomeTaxesReceivable	-8110000	USD
CY2019	us-gaap	Increase Decrease In Customer Deposits IncreaseDecreaseInCustomerDeposits	-1811000	USD
CY2018	us-gaap	Increase Decrease In Customer Deposits IncreaseDecreaseInCustomerDeposits	-596000	USD
CY2017	us-gaap	Increase Decrease In Customer Deposits IncreaseDecreaseInCustomerDeposits	5513000	USD
CY2019	us-gaap	Increase Decrease In Employee Related Liabilities IncreaseDecreaseInEmployeeRelatedLiabilities	2120000	USD
CY2018	us-gaap	Increase Decrease In Employee Related Liabilities IncreaseDecreaseInEmployeeRelatedLiabilities	708000	USD
CY2017	us-gaap	Increase Decrease In Employee Related Liabilities IncreaseDecreaseInEmployeeRelatedLiabilities	2488000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-16064000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-35498000	USD
CY2017	us-gaap	Increase Decrease In Outstanding Checks Financing Activities IncreaseDecreaseInOutstandingChecksFinancingActivities	1738000	USD
CY2017	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	-10000	USD
CY2018	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	1210000	USD
CY2017	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	692000	USD
CY2019	us-gaap	Increase Decrease In Outstanding Checks Financing Activities IncreaseDecreaseInOutstandingChecksFinancingActivities	-1174000	USD
CY2018	us-gaap	Increase Decrease In Outstanding Checks Financing Activities IncreaseDecreaseInOutstandingChecksFinancingActivities	-5943000	USD
CY2019	us-gaap	Proceeds From Repayments Of Lines Of Credit ProceedsFromRepaymentsOfLinesOfCredit	-45913000	USD
CY2018	us-gaap	Proceeds From Repayments Of Lines Of Credit ProceedsFromRepaymentsOfLinesOfCredit	49432000	USD
CY2017	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-2645000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	102964000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	117362000	USD
CY2017	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	110089000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	184727000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	240351000	USD
CY2017	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	175329000	USD
CY2019	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	427000	USD
CY2018	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	782000	USD
CY2017	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	708000	USD
CY2019	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	23988000	USD
CY2018	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	16654000	USD
CY2017	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	11945000	USD
CY2019	us-gaap	Proceeds From Divestiture Of Businesses ProceedsFromDivestitureOfBusinesses	22871000	USD
CY2019	us-gaap	Payments For Environmental Liabilities PaymentsForEnvironmentalLiabilities	1170000	USD
CY2018	us-gaap	Payments For Environmental Liabilities PaymentsForEnvironmentalLiabilities	625000	USD
CY2017	us-gaap	Payments For Environmental Liabilities PaymentsForEnvironmentalLiabilities	329000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-186587000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-256848000	USD
CY2017	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-186895000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	24693000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	22043000	USD
CY2017	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	19928000	USD
CY2019	us-gaap	Proceeds From Repurchase Of Equity ProceedsFromRepurchaseOfEquity	-721000	USD
CY2018	us-gaap	Proceeds From Repurchase Of Equity ProceedsFromRepurchaseOfEquity	-706000	USD
CY2017	us-gaap	Proceeds From Repurchase Of Equity ProceedsFromRepurchaseOfEquity	89000	USD
CY2019	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
CY2018	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
CY2019	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	692000	USD
CY2017	us-gaap	Proceeds From Repayments Of Lines Of Credit ProceedsFromRepaymentsOfLinesOfCredit	39338000	USD
CY2019	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	199648000	USD
CY2018	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	154819000	USD
CY2018	cpk	Non Cash Performance Incentive Plan Expenses NonCashPerformanceIncentivePlanExpenses	2006000	USD
CY2017	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	69807000	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	41936000	USD
CY2018	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	34388000	USD
CY2017	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	12100000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	84519000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	139961000	USD
CY2017	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	78242000	USD
CY2019	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	896000	USD
CY2018	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	475000	USD
CY2017	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	1436000	USD
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	6089000	USD
CY2017Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	5614000	USD
CY2016Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	4178000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	6985000	USD
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	6089000	USD
CY2017Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	5614000	USD
CY2016Q4	us-gaap	Stockholders Equity StockholdersEquity	446086000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	58124000	USD
CY2017	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	606000	USD
CY2017	us-gaap	Dividends Dividends	21045000	USD
CY2017	cpk	Stock Issued During The Period Value Retirement Savings Plan And Dividend Reinvestment Plan StockIssuedDuringThePeriodValueRetirementSavingsPlanAndDividendReinvestmentPlan	735000	USD
CY2017	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	-10000	USD
CY2017	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	1798000	USD
CY2017	cpk	Treasury Stock Activity And Deferred Compensation Plan Activity During Period Value TreasuryStockActivityAndDeferredCompensationPlanActivityDuringPeriodValue	0	USD
CY2017Q4	us-gaap	Stockholders Equity StockholdersEquity	486294000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	56580000	USD
CY2018	us-gaap	New Accounting Pronouncement Or Change In Accounting Principle Effect Of Adoption Quantification NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification	-1498000	USD
CY2018	us-gaap	New Accounting Pronouncement Or Change In Accounting Principle Effect Of Adoption Quantification NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification	-1498000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-1534000	USD
CY2018	us-gaap	Dividends Dividends	23600000	USD
CY2018	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	-3000	USD
CY2018	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	2200000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	518439000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	65153000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	65153000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	561000	USD
CY2019	us-gaap	Dividends Dividends	26191000	USD
CY2019	us-gaap	Stock Issued During Period Value Dividend Reinvestment Plan StockIssuedDuringPeriodValueDividendReinvestmentPlan	-3000	USD
CY2019	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	3618000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	561577000	USD
CY2019Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	2000000	shares
CY2019Q4	cpk	Shares Held In Trust For Deferred Compensation Plan SharesHeldInTrustForDeferredCompensationPlan	95329	shares
CY2019Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2018Q4	cpk	Shares Held In Trust For Deferred Compensation Plan SharesHeldInTrustForDeferredCompensationPlan	97053	shares
CY2017Q4	cpk	Shares Held In Trust For Deferred Compensation Plan SharesHeldInTrustForDeferredCompensationPlan	90961	shares
CY2019	cpk	Shares Issued Under Performance Incentive Plan Withheld For Employee Taxes SharesIssuedUnderPerformanceIncentivePlanWithheldForEmployeeTaxes	7635	shares
CY2018	cpk	Shares Issued Under Performance Incentive Plan Withheld For Employee Taxes SharesIssuedUnderPerformanceIncentivePlanWithheldForEmployeeTaxes	16918	shares
CY2017	cpk	Shares Issued Under Performance Incentive Plan Withheld For Employee Taxes SharesIssuedUnderPerformanceIncentivePlanWithheldForEmployeeTaxes	10269	shares
CY2019	us-gaap	Use Of Estimates UseOfEstimates	<div style="line-height:120%;padding-top:18px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;font-style:italic;font-weight:bold;">Use of Estimates</span></div><div style="line-height:120%;padding-top:6px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates in measuring assets and liabilities and related revenues and expenses. These estimates involve judgments about various future economic factors that are difficult to predict and are beyond our control; therefore, actual results could differ from these estimates. As additional information becomes available, or actual amounts are determined, recorded estimates are revised. Consequently, operating results can be affected by revisions to prior accounting estimates. </span></div>
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1746532000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1568441000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	336876000	USD
CY2018Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	294089000	USD
CY2019Q4	us-gaap	Construction In Progress Gross ConstructionInProgressGross	54141000	USD
CY2018Q4	us-gaap	Construction In Progress Gross ConstructionInProgressGross	79168000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	1463797000	USD
CY2018Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	1353520000	USD
CY2019Q4	us-gaap	Contributions In Aid Of Construction ContributionsInAidOfConstruction	2100000	USD
CY2018Q4	us-gaap	Contributions In Aid Of Construction ContributionsInAidOfConstruction	2800000	USD
CY2019	us-gaap	Public Utilities Allowance For Funds Used During Construction Additions PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions	700000	USD
CY2018	us-gaap	Public Utilities Allowance For Funds Used During Construction Additions PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions	1900000	USD
CY2019	cpk	Numberof Monthsto Establish Rou Assetand Liability NumberofMonthstoEstablishROUAssetandLiability	P12M
CY2019	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	61142000	USD
CY2019	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	8800000	USD
CY2018	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	8500000	USD
CY2017	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	8100000	USD
CY2019	cpk	Delayof Revenue Recognition Due To Implementationof New Standard DelayofRevenueRecognitionDueToImplementationofNewStandard	2	utility
CY2019	cpk	Lengthoftimeuntildeferredamountsrecoveredorrefunded Lengthoftimeuntildeferredamountsrecoveredorrefunded	1
CY2018	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	56862000	USD
CY2017	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	60326000	USD
CY2019	cpk	Discontinued Operation Gain Losson Disposalof Discontinued Operation Netof Lossfrom Discontinued Operations Netof Tax DiscontinuedOperationGainLossonDisposalofDiscontinuedOperationNetofLossfromDiscontinuedOperationsNetofTax	4011000	USD
CY2018	us-gaap	Disposal Group Including Discontinued Operation Revenue DisposalGroupIncludingDiscontinuedOperationRevenue	258713000	USD
CY2019	cpk	Maturity Period To Be Considered Cash Equivalents MaturityPeriodToBeConsideredCashEquivalents	P3M
CY2017	cpk	Discontinued Operation Gain Losson Disposalof Discontinued Operation Netof Lossfrom Discontinued Operations Netof Tax DiscontinuedOperationGainLossonDisposalofDiscontinuedOperationNetofLossfromDiscontinuedOperationsNetofTax	-2202000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	65153000	USD
CY2018	cpk	Discontinued Operation Gain Losson Disposalof Discontinued Operation Netof Lossfrom Discontinued Operations Netof Tax DiscontinuedOperationGainLossonDisposalofDiscontinuedOperationNetofLossfromDiscontinuedOperationsNetofTax	-282000	USD
CY2017	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.56
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	16448486	shares
CY2018	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	-0.02
CY2017	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	46563	shares
CY2017	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	-0.13
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.97
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.46
CY2018	us-gaap	Net Income Loss NetIncomeLoss	56580000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	58124000	USD
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16398443	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16369616	shares
CY2017	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16336789	shares
CY2019	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	3.73
CY2018	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	3.48
CY2017	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	3.69
CY2019	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	0.24
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16398443	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16369616	shares
CY2017	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	16336789	shares
CY2019	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	50043	shares
CY2018	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	50254	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	16419870	shares
CY2017	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	16383352	shares
CY2019	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	3.72
CY2018	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	3.47
CY2017	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	3.68
CY2019	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax Per Diluted Share DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTaxPerDilutedShare	0.24
CY2018	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax Per Diluted Share DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTaxPerDilutedShare	-0.02
CY2017	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax Per Diluted Share DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTaxPerDilutedShare	-0.13
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.96
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.45
CY2017	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.55
CY2019Q4	cpk	Numberof Transactions NumberofTransactions	4
CY2019	us-gaap	Proceeds From Divestiture Of Businesses ProceedsFromDivestitureOfBusinesses	22900000	USD
CY2019	us-gaap	Discontinued Operation Gain Loss From Disposal Of Discontinued Operation Before Income Tax DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax	7300000	USD
CY2019	us-gaap	Disposal Group Including Discontinued Operation Revenue DisposalGroupIncludingDiscontinuedOperationRevenue	161289000	USD
CY2017	us-gaap	Disposal Group Including Discontinued Operation Revenue DisposalGroupIncludingDiscontinuedOperationRevenue	184519000	USD
CY2019	us-gaap	Disposal Group Including Discontinued Operation Costs Of Goods Sold DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold	157646000	USD
CY2018	us-gaap	Disposal Group Including Discontinued Operation Costs Of Goods Sold DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold	252111000	USD
CY2017	us-gaap	Disposal Group Including Discontinued Operation Costs Of Goods Sold DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold	182307000	USD
CY2019	us-gaap	Disposal Group Including Discontinued Operation Operating Expense DisposalGroupIncludingDiscontinuedOperationOperatingExpense	5222000	USD
CY2018	us-gaap	Disposal Group Including Discontinued Operation Operating Expense DisposalGroupIncludingDiscontinuedOperationOperatingExpense	6825000	USD
CY2017	us-gaap	Disposal Group Including Discontinued Operation Operating Expense DisposalGroupIncludingDiscontinuedOperationOperatingExpense	4522000	USD
CY2019	us-gaap	Disposal Group Including Discontinued Operation Operating Income Loss DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss	-1579000	USD
CY2018	us-gaap	Disposal Group Including Discontinued Operation Operating Income Loss DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss	-223000	USD
CY2017	us-gaap	Disposal Group Including Discontinued Operation Operating Income Loss DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss	-2310000	USD
CY2019	us-gaap	Disposal Group Including Discontinued Operation Interest Expense DisposalGroupIncludingDiscontinuedOperationInterestExpense	315000	USD
CY2018	us-gaap	Disposal Group Including Discontinued Operation Interest Expense DisposalGroupIncludingDiscontinuedOperationInterestExpense	297000	USD
CY2017	us-gaap	Disposal Group Including Discontinued Operation Interest Expense DisposalGroupIncludingDiscontinuedOperationInterestExpense	253000	USD
CY2019	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Before Income Tax DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax	-1894000	USD
CY2018	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Before Income Tax DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax	-520000	USD
CY2017	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Before Income Tax DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax	-2563000	USD
CY2019	us-gaap	Discontinued Operation Gain Loss From Disposal Of Discontinued Operation Before Income Tax DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax	7344000	USD
CY2018	us-gaap	Discontinued Operation Gain Loss From Disposal Of Discontinued Operation Before Income Tax DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax	0	USD
CY2017	us-gaap	Discontinued Operation Gain Loss From Disposal Of Discontinued Operation Before Income Tax DiscontinuedOperationGainLossFromDisposalOfDiscontinuedOperationBeforeIncomeTax	0	USD
CY2019	us-gaap	Discontinued Operation Tax Effect Of Income Loss From Disposal Of Discontinued Operation DiscontinuedOperationTaxEffectOfIncomeLossFromDisposalOfDiscontinuedOperation	-1439000	USD
CY2018	us-gaap	Discontinued Operation Tax Effect Of Income Loss From Disposal Of Discontinued Operation DiscontinuedOperationTaxEffectOfIncomeLossFromDisposalOfDiscontinuedOperation	-238000	USD
CY2017	us-gaap	Discontinued Operation Tax Effect Of Income Loss From Disposal Of Discontinued Operation DiscontinuedOperationTaxEffectOfIncomeLossFromDisposalOfDiscontinuedOperation	-361000	USD
CY2018	cpk	Gain Loss From Discontinued Operations GainLossFromDiscontinuedOperations	-282000	USD
CY2017	cpk	Gain Loss From Discontinued Operations GainLossFromDiscontinuedOperations	-2202000	USD
CY2018Q4	us-gaap	Disposal Group Including Discontinued Operation Property Plant And Equipment Noncurrent DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent	1242000	USD
CY2018Q4	us-gaap	Disposal Group Including Discontinued Operation Property Plant And Equipment DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment	1036000	USD
CY2018Q4	us-gaap	Disposal Group Including Discontinued Operation Other Assets DisposalGroupIncludingDiscontinuedOperationOtherAssets	6626000	USD
CY2018Q4	us-gaap	Assets Of Disposal Group Including Discontinued Operation AssetsOfDisposalGroupIncludingDiscontinuedOperation	60343000	USD
CY2018Q4	us-gaap	Liabilities Of Disposal Group Including Discontinued Operation LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation	48672000	USD
CY2018Q4	us-gaap	Liabilities Of Disposal Group Including Discontinued Operation LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation	48672000	USD
CY2019	us-gaap	Disposal Group Including Discontinued Operation Depreciation And Amortization DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization	477000	USD
CY2018	us-gaap	Disposal Group Including Discontinued Operation Depreciation And Amortization DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization	582000	USD
CY2017	us-gaap	Disposal Group Including Discontinued Operation Depreciation And Amortization DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization	213000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	479604000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	490316000	USD
CY2018Q4	us-gaap	Receivables From Customers ReceivablesFromCustomers	52140000	USD
CY2018Q4	us-gaap	Contract With Customer Asset Net Noncurrent ContractWithCustomerAssetNetNoncurrent	2614000	USD
CY2018Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	480000	USD
CY2019Q4	us-gaap	Receivables From Customers ReceivablesFromCustomers	47430000	USD
CY2019Q4	us-gaap	Contract With Customer Asset Net Noncurrent ContractWithCustomerAssetNetNoncurrent	3465000	USD
CY2019Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	589000	USD
CY2019	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	-4710000	USD
CY2019	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	851000	USD
CY2019	us-gaap	Increase Decrease In Other Current Liabilities IncreaseDecreaseInOtherCurrentLiabilities	109000	USD
CY2019	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	1000000.0	USD
CY2018	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	700000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	106287000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	94843000	USD
CY2017	us-gaap	Operating Income Loss OperatingIncomeLoss	89730000	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-1830000	USD
CY2018	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-603000	USD
CY2017	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-2204000	USD
CY2019	us-gaap	Interest Expense InterestExpense	22224000	USD
CY2018	us-gaap	Interest Expense InterestExpense	16146000	USD
CY2017	us-gaap	Interest Expense InterestExpense	12530000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	82233000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	78094000	USD
CY2017	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	74996000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21091000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21232000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14670000	USD
CY2019	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	61142000	USD
CY2018	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	56862000	USD
CY2017	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	60326000	USD
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-1391000	USD
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-282000	USD
CY2017	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-2202000	USD
CY2019	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax	5402000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	65153000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	56580000	USD
CY2017	us-gaap	Net Income Loss NetIncomeLoss	58124000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	45423000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	40220000	USD
CY2017	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	36386000	USD
CY2019Q4	us-gaap	Assets Assets	1783198000	USD
CY2019	us-gaap	Interest Paid InterestPaid	22611000	USD
CY2018	us-gaap	Interest Paid InterestPaid	16741000	USD
CY2017	us-gaap	Interest Paid InterestPaid	12420000	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	3221000	USD
CY2018	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	477000	USD
CY2017	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	-4114000	USD
CY2019	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	13470000	USD
CY2018	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	39402000	USD
CY2017	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	15457000	USD
CY2019	cpk	Non Cash Performance Incentive Plan Expenses NonCashPerformanceIncentivePlanExpenses	1691000	USD
CY2017	cpk	Non Cash Performance Incentive Plan Expenses NonCashPerformanceIncentivePlanExpenses	1127000	USD
CY2019	us-gaap	Capital Lease Obligations Incurred CapitalLeaseObligationsIncurred	0	USD
CY2018	us-gaap	Capital Lease Obligations Incurred CapitalLeaseObligationsIncurred	1310000	USD
CY2017	us-gaap	Capital Lease Obligations Incurred CapitalLeaseObligationsIncurred	2070000	USD
CY2019Q4	us-gaap	Energy Marketing Contracts Assets Current EnergyMarketingContractsAssetsCurrent	0	USD
CY2018Q4	us-gaap	Energy Marketing Contracts Assets Current EnergyMarketingContractsAssetsCurrent	82000	USD
CY2019Q4	us-gaap	Energy Marketing Contract Liabilities Current EnergyMarketingContractLiabilitiesCurrent	1844000	USD
CY2018Q4	us-gaap	Energy Marketing Contract Liabilities Current EnergyMarketingContractLiabilitiesCurrent	1604000	USD
CY2019	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	910000	USD
CY2018	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	-2701000	USD
CY2017	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	1715000	USD
CY2018Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	686000	USD
CY2017Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	648000	USD
CY2019	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases Sales Issuances Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlements	131000	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases Sales Issuances Settlements FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlements	68000	USD
CY2019	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	29000	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales	41000	USD
CY2019	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	15000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	7316000	USD
CY2018Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	3466000	USD
CY2018Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	686000	USD
CY2018	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1	11000	USD
CY2019Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	803000	USD
CY2019Q4	us-gaap	Long Term Debt LongTermDebt	486600000	USD
CY2019Q4	us-gaap	Long Term Debt Fair Value LongTermDebtFairValue	505000000.0	USD
CY2018Q4	us-gaap	Long Term Debt LongTermDebt	327200000	USD
CY2019	us-gaap	Acquired Finite Lived Intangible Assets Weighted Average Useful Life AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife	P11Y
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	800000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	400000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	12365000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	4236000	USD
CY2018Q4	us-gaap	Long Term Debt Fair Value LongTermDebtFairValue	323800000	USD
CY2019Q4	us-gaap	Investments Fair Value Disclosure InvestmentsFairValueDisclosure	9229000	USD
CY2018Q4	us-gaap	Investments Fair Value Disclosure InvestmentsFairValueDisclosure	6711000	USD
CY2019	us-gaap	Trading Securities Unrealized Holding Gain Loss TradingSecuritiesUnrealizedHoldingGainLoss	1600000	USD
CY2018	us-gaap	Trading Securities Unrealized Holding Gain Loss TradingSecuritiesUnrealizedHoldingGainLoss	-400000	USD
CY2017	us-gaap	Trading Securities Unrealized Holding Gain Loss TradingSecuritiesUnrealizedHoldingGainLoss	1000000.0	USD
CY2019Q4	us-gaap	Goodwill Goodwill	32668000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	21568000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	1200000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	900000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	800000	USD
CY2019Q4	cpk	Net Operating Losses And Tax Carryforwards NetOperatingLossesAndTaxCarryforwards	-3000000.0	USD
CY2018Q4	cpk	Net Operating Losses And Tax Carryforwards NetOperatingLossesAndTaxCarryforwards	-12200000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	5500000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	2000000.0	USD
CY2017	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.35
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-2271000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	48000	USD
CY2017	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	2046000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	-492000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	581000	USD
CY2017	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	610000	USD
CY2019	us-gaap	Income Tax Credits And Adjustments IncomeTaxCreditsAndAdjustments	-47000	USD
CY2018	us-gaap	Income Tax Credits And Adjustments IncomeTaxCreditsAndAdjustments	-47000	USD
CY2017	us-gaap	Income Tax Credits And Adjustments IncomeTaxCreditsAndAdjustments	-71000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	-2810000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	582000	USD
CY2017	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	2585000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	23901000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	20650000	USD
CY2017	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	12085000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21091000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21232000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14670000	USD
CY2019	us-gaap	Discontinued Operation Tax Effect Of Income Loss From Disposal Of Discontinued Operation DiscontinuedOperationTaxEffectOfIncomeLossFromDisposalOfDiscontinuedOperation	-1439000	USD
CY2018	us-gaap	Discontinued Operation Tax Effect Of Income Loss From Disposal Of Discontinued Operation DiscontinuedOperationTaxEffectOfIncomeLossFromDisposalOfDiscontinuedOperation	-238000	USD
CY2017	us-gaap	Discontinued Operation Tax Effect Of Income Loss From Disposal Of Discontinued Operation DiscontinuedOperationTaxEffectOfIncomeLossFromDisposalOfDiscontinuedOperation	-361000	USD
CY2019	us-gaap	Income Tax Expense Benefit Continuing Operations Discontinued Operations Extraordinary Items IncomeTaxExpenseBenefitContinuingOperationsDiscontinuedOperationsExtraordinaryItems	22530000	USD
CY2018	us-gaap	Income Tax Expense Benefit Continuing Operations Discontinued Operations Extraordinary Items IncomeTaxExpenseBenefitContinuingOperationsDiscontinuedOperationsExtraordinaryItems	20994000	USD
CY2017	us-gaap	Income Tax Expense Benefit Continuing Operations Discontinued Operations Extraordinary Items IncomeTaxExpenseBenefitContinuingOperationsDiscontinuedOperationsExtraordinaryItems	14309000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	4700000	USD
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	3500000	USD
CY2017	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	900000	USD
CY2019	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	17246000	USD
CY2018	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	16491000	USD
CY2017	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	26249000	USD
CY2019	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	5088000	USD
CY2018	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	4057000	USD
CY2017	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	2000000	USD
CY2019	us-gaap	Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends IncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	173000	USD
CY2018	us-gaap	Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends IncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	158000	USD
CY2019	us-gaap	Income Tax Reconciliation Change In Enacted Tax Rate IncomeTaxReconciliationChangeInEnactedTaxRate	0	USD
CY2017	us-gaap	Income Tax Rate Reconciliation Deductions Employee Stock Ownership Plan Dividends IncomeTaxRateReconciliationDeductionsEmployeeStockOwnershipPlanDividends	257000	USD
CY2018	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	842000	USD
CY2017	us-gaap	Income Tax Reconciliation Change In Enacted Tax Rate IncomeTaxReconciliationChangeInEnactedTaxRate	-14299000	USD
CY2019	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	-1070000	USD
CY2017	us-gaap	Income Tax Reconciliation Other Reconciling Items IncomeTaxReconciliationOtherReconcilingItems	977000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21091000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	21232000	USD
CY2017	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	14670000	USD
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.2565
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.2719
CY2017	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.1956
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21
CY2017	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.35
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	173466000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	153423000	USD
CY2019Q4	cpk	Deferred Income Tax On Acquisition Adjustment DeferredIncomeTaxOnAcquisitionAdjustment	6969000	USD
CY2018Q4	cpk	Deferred Income Tax On Acquisition Adjustment DeferredIncomeTaxOnAcquisitionAdjustment	8896000	USD
CY2019Q4	cpk	Deferred Tax Liabilities Loss On Reacquired Debt DeferredTaxLiabilitiesLossOnReacquiredDebt	220000	USD
CY2018Q4	cpk	Deferred Tax Liabilities Loss On Reacquired Debt DeferredTaxLiabilitiesLossOnReacquiredDebt	32000	USD
CY2019Q4	cpk	Deferred Income Tax Liability Deferred Gas Costs DeferredIncomeTaxLiabilityDeferredGasCosts	1223000	USD
CY2018Q4	cpk	Deferred Income Tax Liability Deferred Gas Costs DeferredIncomeTaxLiabilityDeferredGasCosts	1139000	USD
CY2019Q4	cpk	Deferred Income Tax Liability Natural Gas Conversion Costs DeferredIncomeTaxLiabilityNaturalGasConversionCosts	4956000	USD
CY2018Q4	cpk	Deferred Income Tax Liability Natural Gas Conversion Costs DeferredIncomeTaxLiabilityNaturalGasConversionCosts	3987000	USD
CY2019Q4	cpk	Deferred Income Tax Liability Storm Reserve DeferredIncomeTaxLiabilityStormReserve	10316000	USD
CY2018Q4	cpk	Deferred Income Tax Liability Storm Reserve DeferredIncomeTaxLiabilityStormReserve	97000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	1456000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	2544000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	198606000	USD
CY2018Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	170118000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	3818000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	3711000	USD
CY2019Q4	cpk	Deferred Tax Assets Environmental DeferredTaxAssetsEnvironmental	1486000	USD
CY2018Q4	cpk	Deferred Tax Assets Environmental DeferredTaxAssetsEnvironmental	1710000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	5523000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	2010000	USD
CY2019Q4	cpk	Deferred Tax Asset Self Insurance Accruals DeferredTaxAssetSelfInsuranceAccruals	146000	USD
CY2018Q4	cpk	Deferred Tax Asset Self Insurance Accruals DeferredTaxAssetSelfInsuranceAccruals	151000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Reserves DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsReserves	96000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Reserves DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsReserves	0	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	6881000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	5716000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	17950000	USD
CY2018Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	13298000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	180656000	USD
CY2018Q4	us-gaap	Deferred Income Tax Liabilities Net DeferredIncomeTaxLiabilitiesNet	156820000	USD
CY2019Q4	us-gaap	Capital Lease Obligations CapitalLeaseObligations	0	USD
CY2018Q4	us-gaap	Capital Lease Obligations CapitalLeaseObligations	1310000	USD
CY2019Q4	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	822000	USD
CY2018Q4	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	567000	USD
CY2019Q4	us-gaap	Long Term Debt And Capital Lease Obligations LongTermDebtAndCapitalLeaseObligations	485768000	USD
CY2018Q4	us-gaap	Long Term Debt And Capital Lease Obligations LongTermDebtAndCapitalLeaseObligations	327955000	USD
CY2019Q4	us-gaap	Long Term Debt And Capital Lease Obligations Current LongTermDebtAndCapitalLeaseObligationsCurrent	45600000	USD
CY2018Q4	us-gaap	Long Term Debt And Capital Lease Obligations Current LongTermDebtAndCapitalLeaseObligationsCurrent	11935000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	440168000	USD
CY2018Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	316020000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	45600000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	13600000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	25100000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	20600000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	17600000	USD
CY2019Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	364100000	USD
CY2019Q4	cpk	Total Future Repayments TotalFutureRepayments	486600000	USD
CY2019Q4	us-gaap	Debt Instrument Unused Borrowing Capacity Amount DebtInstrumentUnusedBorrowingCapacityAmount	250000000	USD
CY2019Q4	us-gaap	Amount Of Restricted Net Assets For Consolidated And Unconsolidated Subsidiaries AmountOfRestrictedNetAssetsForConsolidatedAndUnconsolidatedSubsidiaries	38800000	USD
CY2019Q4	us-gaap	Restricted Investments Percent Of Net Assets RestrictedInvestmentsPercentOfNetAssets	0.0692
CY2019Q4	cpk	Common Stock Equity To Total Capitalization CommonStockEquityToTotalCapitalization	0.400
CY2019Q4	cpk	Required Fixed Charge Coverage Ratio RequiredFixedChargeCoverageRatio	1.2
CY2019Q4	us-gaap	Line Of Credit Facility Remaining Borrowing Capacity LineOfCreditFacilityRemainingBorrowingCapacity	125810000	USD
CY2019Q4	us-gaap	Bank Overdrafts BankOverdrafts	3181000	USD
CY2018Q4	us-gaap	Bank Overdrafts BankOverdrafts	4355000	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	247371000	USD
CY2018Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	294458000	USD
CY2019	us-gaap	Shortterm Debt Maximum Amount Outstanding During Period ShorttermDebtMaximumAmountOutstandingDuringPeriod	250000000.0	USD
CY2019Q4	us-gaap	Ratio Of Indebtedness To Net Capital1 RatioOfIndebtednessToNetCapital1	0.65
CY2019Q4	cpk	Debt Instrument Restrictive Covenants Required Net Book Valueof Regulated Business Assets Percentageof Consolidated Total Assets DebtInstrumentRestrictiveCovenantsRequiredNetBookValueofRegulatedBusinessAssetsPercentageofConsolidatedTotalAssets	0.500
CY2019	cpk	Longterm Debt Debt Covenants Maximum Allowable Amountof Restricted Payments LongtermDebtDebtCovenantsMaximumAllowableAmountofRestrictedPayments	10000000.0	USD
CY2019Q4	cpk	Cumulative Consolidated Net Income CumulativeConsolidatedNetIncome	509500000	USD
CY2019Q4	cpk	Restricted Payment RestrictedPayment	227500000	USD
CY2019Q4	cpk	Unrestricted Payment UnrestrictedPayment	282000000.0	USD
CY2018Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	294500000	USD
CY2019Q4	us-gaap	Short Term Debt Weighted Average Interest Rate ShortTermDebtWeightedAverageInterestRate	0.0262
CY2018Q4	us-gaap	Short Term Debt Weighted Average Interest Rate ShortTermDebtWeightedAverageInterestRate	0.0344
CY2019Q4	us-gaap	Line Of Credit Facility Maximum Borrowing Capacity LineOfCreditFacilityMaximumBorrowingCapacity	370000000.0	USD
CY2019	cpk	Number Of Unsecured Bank Credit Facilities NumberOfUnsecuredBankCreditFacilities	4
CY2019	cpk	Number Of Financial Institutions With Bank Credit Facilities NumberOfFinancialInstitutionsWithBankCreditFacilities	4
CY2019Q4	cpk	Line Of Credit Facility Maximum Borrowing Committed Capacity LineOfCreditFacilityMaximumBorrowingCommittedCapacity	220000000.0	USD
CY2019Q4	cpk	Participating Lenders In The Revolver ParticipatingLendersInTheRevolver	5
CY2019	us-gaap	Line Of Credit Facility Commitment Fee Amount LineOfCreditFacilityCommitmentFeeAmount	100000	USD
CY2019Q4	us-gaap	Line Of Credit Facility Maximum Borrowing Capacity LineOfCreditFacilityMaximumBorrowingCapacity	370000000	USD
CY2019Q4	us-gaap	Lines Of Credit Current LinesOfCreditCurrent	244190000	USD
CY2018Q4	us-gaap	Lines Of Credit Current LinesOfCreditCurrent	290103000	USD
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	2577000	USD
CY2018	us-gaap	Operating Lease Cost OperatingLeaseCost	3339000	USD
CY2019	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	650000	USD
CY2018	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	1451000	USD
CY2019	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	5000	USD
CY2018	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	49000	USD
CY2019	us-gaap	Lease Cost LeaseCost	3232000	USD
CY2018	us-gaap	Lease Cost LeaseCost	4839000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	11563000	USD
CY2019Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	1705000	USD
CY2019Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	9896000	USD
CY2019Q4	cpk	Total Operatingand Finance Lease Liabilities TotalOperatingandFinanceLeaseLiabilities	11601000	USD
CY2019Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P8Y10M17D
CY2019Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.038
CY2019	us-gaap	Operating Lease Payments OperatingLeasePayments	2230000	USD
CY2018	us-gaap	Operating Lease Payments OperatingLeasePayments	2759000	USD
CY2019	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	5000	USD
CY2018	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	49000	USD
CY2019	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	650000	USD
CY2018	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	1451000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	2104000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	1866000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	1716000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	1719000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	1463000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	4916000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	13784000	USD
CY2019Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	2183000	USD
CY2019Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	11601000	USD
CY2019Q4	cpk	Lessee Future Operating Lease Option Payments LesseeFutureOperatingLeaseOptionPayments	3700000	USD
CY2017Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-4272000	USD
CY2018Q1	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-3732000	USD
CY2018Q1	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-2198000	USD
CY2018Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-1534000	USD
CY2018Q1	cpk	Tax Cutsand Jobs Act Reclassificationfrom Aoc Ito Retained Earnings Tax Effect TaxCutsandJobsActReclassificationfromAOCItoRetainedEarningsTaxEffect	-907000	USD
CY2018Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-6713000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	1289000	USD
CY2019	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	728000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	561000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-6267000	USD
CY2019Q4	cpk	Numberof Plans NumberofPlans	3	plan
CY2019	cpk	Deferred Pension Settlement Expense DeferredPensionSettlementExpense	-700000	USD
CY2018Q4	cpk	Numberof Sub Plans NumberofSubPlans	2
CY2019	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	74000	USD
CY2018	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	83000	USD
CY2017	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	89000	USD
CY2019	cpk	Deferred Pension Settlement Expense DeferredPensionSettlementExpense	-700000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	54333000	USD
CY2018Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	52250000	USD
CY2019Q4	cpk	Defined Benefit Plan Fair Valueof Plan Assets Excluding Net Asset Value Investments DefinedBenefitPlanFairValueofPlanAssetsExcludingNetAssetValueInvestments	47316000	USD
CY2018Q4	cpk	Defined Benefit Plan Fair Valueof Plan Assets Excluding Net Asset Value Investments DefinedBenefitPlanFairValueofPlanAssetsExcludingNetAssetValueInvestments	46692000	USD
CY2019Q4	cpk	Defined Benefit Plan Alternative Investments Fair Valueof Plan Assets DefinedBenefitPlanAlternativeInvestmentsFairValueofPlanAssets	7017000	USD
CY2018Q4	cpk	Defined Benefit Plan Alternative Investments Fair Valueof Plan Assets DefinedBenefitPlanAlternativeInvestmentsFairValueofPlanAssets	5558000	USD
CY2019	cpk	Expected Amortization Of Pre Merger Regulatory Asset ExpectedAmortizationOfPreMergerRegulatoryAsset	0	USD
CY2019	us-gaap	Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Net Prior Service Cost Credit Before Tax DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax	-447000	USD
CY2019	us-gaap	Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Loss Net Gain Loss Before Tax DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax	-22727000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	22280000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax	-6641000	USD
CY2019Q4	cpk	Defined Benefit Plan Post Merger Regulatory Assets DefinedBenefitPlanPostMergerRegulatoryAssets	15639000	USD
CY2019Q4	cpk	Defined Benefit Plan Regulatory Assets Before Premerger DefinedBenefitPlanRegulatoryAssetsBeforePremerger	22280000	USD
CY2019Q4	cpk	Defined Benefit Plan Pre Merger Regulatory Assets DefinedBenefitPlanPreMergerRegulatoryAssets	6000	USD
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	792	shares
CY2019Q4	us-gaap	Defined Benefit Plan Accumulated Benefit Obligation DefinedBenefitPlanAccumulatedBenefitObligation	22286000	USD
CY2019Q4	cpk	Accumulated Other Comprehensive Income Loss Tax Effect AccumulatedOtherComprehensiveIncomeLossTaxEffect	1700000	USD
CY2019	cpk	Employee Minimum Age To Participate Under Defined Contribution Plan EmployeeMinimumAgeToParticipateUnderDefinedContributionPlan	P55Y
CY2019Q4	cpk	Deferrals Rates After Deferral Period Ends Minimum DeferralsRatesAfterDeferralPeriodEndsMinimum	0.01
CY2019	us-gaap	Deferred Compensation Arrangement With Individual Requisite Service Period1 DeferredCompensationArrangementWithIndividualRequisiteServicePeriod1	P2Y
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	3410000	USD
CY2019	cpk	Defined Contribution Plan Eligibility Threshold Requisite Service Period DefinedContributionPlanEligibilityThresholdRequisiteServicePeriod	P3M
CY2019	cpk	Defined Contribution Plan Maximum Employer Contribution As Percentage Of Eligible Compensation DefinedContributionPlanMaximumEmployerContributionAsPercentageOfEligibleCompensation	1
CY2019	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent Of Match DefinedContributionPlanEmployerMatchingContributionPercentOfMatch	0.06
CY2019	us-gaap	Defined Contribution Plan Employers Matching Contribution Annual Vesting Percentage DefinedContributionPlanEmployersMatchingContributionAnnualVestingPercentage	1
CY2019	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	5700000	USD
CY2018	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	5500000	USD
CY2017	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	5000000.0	USD
CY2019Q4	us-gaap	Common Stock Capital Shares Reserved For Future Issuance CommonStockCapitalSharesReservedForFutureIssuance	831183	shares
CY2019	cpk	Employee Deferral Rate EmployeeDeferralRate	0.80
CY2019	cpk	Deferred Compensation Employer Matching Contribution Rate DeferredCompensationEmployerMatchingContributionRate	0.06
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	4279000	USD
CY2017	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	2490000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	1117000	USD
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	934000	USD
CY2017	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	1003000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	3162000	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	2476000	USD
CY2017	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	1487000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	751	shares
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Additional Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized	43032	shares
CY2019Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Share Based Awards Other Than Options EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions	4300000	USD
CY2019	cpk	Number Of Multiyear Awards NumberOfMultiyearAwards	3
CY2019	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Accelerated Vesting Number SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber	14107	shares
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Non Option Equity Instruments Forfeitures And Expirations ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsForfeituresAndExpirations	2569	shares
CY2019Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	1100000	USD
CY2019	us-gaap	Shares Paid For Tax Withholding For Share Based Compensation SharesPaidForTaxWithholdingForShareBasedCompensation	7635	shares
CY2018	us-gaap	Shares Paid For Tax Withholding For Share Based Compensation SharesPaidForTaxWithholdingForShareBasedCompensation	16918	shares
CY2017	us-gaap	Shares Paid For Tax Withholding For Share Based Compensation SharesPaidForTaxWithholdingForShareBasedCompensation	10269	shares
CY2019	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	692000	USD
CY2018	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	1210000	USD
CY2017	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	692000	USD
CY2019	us-gaap	Proceeds And Excess Tax Benefit From Sharebased Compensation ProceedsAndExcessTaxBenefitFromSharebasedCompensation	0	USD
CY2017	us-gaap	Proceeds And Excess Tax Benefit From Sharebased Compensation ProceedsAndExcessTaxBenefitFromSharebasedCompensation	349000	USD
CY2019	cpk	Depreciation Expense Decreasefrom Depreciation Study Rate Change DepreciationExpenseDecreasefromDepreciationStudyRateChange	900000	USD
CY2019Q4	us-gaap	Regulatory Assets RegulatoryAssets	78551000	USD
CY2018Q4	us-gaap	Regulatory Assets RegulatoryAssets	77218000	USD
CY2019Q4	us-gaap	Regulatory Liabilities RegulatoryLiabilities	133735000	USD
CY2018Q4	us-gaap	Regulatory Liabilities RegulatoryLiabilities	142922000	USD
CY2019	cpk	Companys Exposure In Number Of Former Manufactured Gas Plant Sites CompanysExposureInNumberOfFormerManufacturedGasPlantSites	7	site
CY2019Q4	cpk	Debt Service Coverage Ratio DebtServiceCoverageRatio	1.25
CY2019	cpk	Ratiobasedonaveragenumberofpriorquarters Ratiobasedonaveragenumberofpriorquarters	6
CY2019Q4	cpk	Minimum Interest Coverage Ratio Under Agreement Two MinimumInterestCoverageRatioUnderAgreementTwo	2
CY2019Q4	cpk	Maximum Debt To Net Capital Ratio Under Agreement Two MaximumDebtToNetCapitalRatioUnderAgreementTwo	65
CY2019	cpk	Number Of Yearsto Collect Benefits NumberOfYearstoCollectBenefits	P20Y
CY2019	cpk	Number Of Yearsto Collect Benefits NumberOfYearstoCollectBenefits	P20Y
CY2019Q4	us-gaap	Purchase Obligation Due In Next Twelve Months PurchaseObligationDueInNextTwelveMonths	60735000	USD
CY2019Q4	us-gaap	Purchase Obligation Due In Second And Third Year PurchaseObligationDueInSecondAndThirdYear	72123000	USD
CY2019Q4	us-gaap	Purchase Obligation Due In Fourth And Fifth Year PurchaseObligationDueInFourthAndFifthYear	60049000	USD
CY2019Q4	us-gaap	Purchase Obligation Due After Fifth Year PurchaseObligationDueAfterFifthYear	201131000	USD
CY2019Q4	us-gaap	Purchase Obligation PurchaseObligation	394038000	USD
CY2019Q4	us-gaap	Guarantee Obligations Maximum Exposure GuaranteeObligationsMaximumExposure	37000000.0	USD
CY2019Q4	us-gaap	Guarantee Obligations Current Carrying Value GuaranteeObligationsCurrentCarryingValue	24700000	USD
CY2019Q4	cpk	Guarantor Obligations Current Carrying Value Pesco GuarantorObligationsCurrentCarryingValuePESCO	16300000	USD
CY2019	cpk	Standby Letters Of Credit StandbyLettersOfCredit	5400000	USD
CY2019Q1	us-gaap	Revenues Revenues	160464000	USD
CY2019Q2	us-gaap	Revenues Revenues	94541000	USD
CY2019Q3	us-gaap	Revenues Revenues	92626000	USD
CY2019Q4	us-gaap	Revenues Revenues	131973000	USD
CY2019Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	44123000	USD
CY2019Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	18164000	USD
CY2019Q4	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	17169000	USD
CY2019Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-149000	USD
CY2019Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	29642000	USD
CY2019Q1	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	28814000	USD
CY2019Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-609000	USD
CY2019Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-624000	USD
CY2019Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	14358000	USD
CY2019Q2	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	8913000	USD
CY2019Q3	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	6246000	USD
CY2019Q2	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	-0.03
CY2019Q3	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	-0.04
CY2019Q4	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	0.33
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.75
CY2019Q1	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	-0.01
CY2019Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-9000	USD
CY2019Q1	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax	0	USD
CY2019Q2	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax	0	USD
CY2019Q3	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax	0	USD
CY2019Q4	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax	5402000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	28665000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	8304000	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	5622000	USD
CY2019Q4	us-gaap	Net Income Loss NetIncomeLoss	22562000	USD
CY2019Q1	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.76
CY2019Q2	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.54
CY2019Q3	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.38
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CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.51
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.34
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CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.33
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.74
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CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.34
CY2019Q4	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.37
CY2018Q1	us-gaap	Revenues Revenues	168831000	USD
CY2018Q2	us-gaap	Revenues Revenues	93872000	USD
CY2018Q3	us-gaap	Revenues Revenues	93400000	USD
CY2018Q4	us-gaap	Revenues Revenues	134214000	USD
CY2018Q1	us-gaap	Operating Income Loss OperatingIncomeLoss	40853000	USD
CY2018Q2	us-gaap	Operating Income Loss OperatingIncomeLoss	12238000	USD
CY2018Q3	us-gaap	Operating Income Loss OperatingIncomeLoss	12879000	USD
CY2018Q4	us-gaap	Operating Income Loss OperatingIncomeLoss	28873000	USD
CY2018Q3	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	6090000	USD
CY2018Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-552000	USD
CY2018Q2	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	5705000	USD
CY2018Q1	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	27271000	USD
CY2018Q4	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	17796000	USD
CY2018Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-415000	USD
CY2018Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	680000	USD
CY2018Q2	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax Per Diluted Share DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTaxPerDilutedShare	0.04
CY2018Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	5000	USD
CY2018Q1	us-gaap	Net Income Loss NetIncomeLoss	26856000	USD
CY2018Q2	us-gaap	Net Income Loss NetIncomeLoss	6385000	USD
CY2018Q3	us-gaap	Net Income Loss NetIncomeLoss	5538000	USD
CY2018Q4	us-gaap	Net Income Loss NetIncomeLoss	17801000	USD
CY2018Q1	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.67
CY2018Q2	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.35
CY2018Q3	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.37
CY2018Q4	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.09
CY2018Q1	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	-0.03
CY2018Q2	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	0.04
CY2018Q3	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	-0.03
CY2018Q4	us-gaap	Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic Share DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare	0
CY2018Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.64
CY2018Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.39
CY2018Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.34
CY2018Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.09
CY2018Q1	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.66
CY2018Q2	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.35
CY2018Q3	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.37
CY2018Q4	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.09
CY2018Q1	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax Per Diluted Share DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTaxPerDilutedShare	-0.02
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CY2018Q4	us-gaap	Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax Per Diluted Share DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTaxPerDilutedShare	0
CY2018Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.64
CY2018Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.39
CY2018Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.33
CY2018Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.09
CY2019	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	1392000	USD
CY2019	us-gaap	Valuation Allowances And Reserves Charged To Other Accounts ValuationAllowancesAndReservesChargedToOtherAccounts	278000	USD
CY2019	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	1391000	USD
CY2019Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	1337000	USD
CY2017Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	897000	USD
CY2018	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	541000	USD
CY2018	us-gaap	Valuation Allowances And Reserves Charged To Other Accounts ValuationAllowancesAndReservesChargedToOtherAccounts	339000	USD
CY2018	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	901000	USD
CY2018Q4	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	876000	USD

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2019 Form 10-K Financial Statement

#000162828020002321 Filed on February 26, 2020

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$CPK CHESAPEAKE UTILITIES CORP Stock $cpk

2019 Form 10-K Financial Statement

#000162828020002321 Filed on February 26, 2020

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$CPK
CHESAPEAKE UTILITIES CORP Stock $cpk