XML 120 R100.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Employee Benefit Plans - Additional Information (Detail) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 USD ($) plan shares | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($)
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined Benefit Plan, Number of Plans | plan |  | 3 |  |
Income tax benefits |  | $ 2,100 |  |
Pre-merger regulatory asset |  | 557 |  |
Total unrecognized cost |  | 23,500 |  |
Expected Amortization Of Pre Merger Regulatory Asset |  | $ 0 |  |
Required period of service for eligibility |  | 3 months |  |
Percentage of eligible participants contribution to the plan |  | 100.00% |  |
Maximum percentage of eligible compensation |  | 6.00% |  |
Employer matching contribution vested, percentage |  | 100.00% |  |
Deferred Compensation Arrangement with Individual, Requisite Service Period |  | 2 years |  |
Defined Benefit Plan, Benefit Obligation |  |  | 2 |
Employee contribution age |  | 55 years |  |
Deferral rate |  | 80.00% |  |
Deferred Compensation Employer Matching Contribution Rate |  | 6.00% |  |
Number Of Years to Collect Benefits |  | 20 years |  |
Deferral rate increase, minimum |  | 1.00% |  |
Employer contributions to pension plan |  | $ 5,500 | $ 5,000 | $ 4,500
Shares reserved to fund future contributions | shares |  | 831,183 |  |
Investments, Fair Value Disclosure |  | $ 6,711 | 6,756 |
Deferred compensation obligation |  | $ 3,854 | 3,395 |
Minimum |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Maximum percentage of eligible compensation |  | 3.00% |  |
Maximum |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Maximum percentage of eligible compensation |  | 10.00% |  |
Number Of Years to Collect Benefits |  | 15 years |  |
Chesapeake Pension Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Pre-merger regulatory asset |  | $ 0 |  |
Total unrecognized cost |  | 3,865 |  |
Unfunded accumulated benefit obligation |  | (2,063) | (2,093) |
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year |  | 163 |  |
Expected contribution | [1] | 528 |  |
FPU Pension Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Merger Related Costs Allowed To Be Recovered In Future Rates |  | 500 |  |
Defined Benefit Plan, Amortization of Transition Asset (Obligation) |  |  | 1,300 |
Pre-merger regulatory asset |  | 543 |  |
Total unrecognized cost |  | 19,087 |  |
Unfunded accumulated benefit obligation |  | (15,776) | (16,268) |
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year |  | 1,200 |  |
Expected contribution | [1] | 3,091 |  |
Chesapeake SERP |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Pre-merger regulatory asset |  | 0 |  |
Total unrecognized cost |  | 559 |  |
Unfunded accumulated benefit obligation |  | (2,285) | (2,428) |
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year |  | 383 |  |
Expected contribution | [2] | $ 383 |  |
Medical |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Health care inflation rate |  | 5.00% |  |
Chesapeake Postretirement Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Pre-merger regulatory asset |  | $ 0 |  |
Total unrecognized cost |  | 54 |  |
Unfunded accumulated benefit obligation |  | $ (1,002) | (1,128) |
Expected Amortization Of Pre Merger Regulatory Asset |  |  | 0 | $ 0
Health care inflation rate |  | 6.00% |  |
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year |  | $ 96 |  |
Expected contribution | [2] | 96 |  |
FPU Medical Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Pre-merger regulatory asset |  | 14 | 22 |
Total unrecognized cost |  | (65) |  |
Unfunded accumulated benefit obligation |  | $ (1,187) | (1,287) |
Health care inflation rate |  | 5.00% |  |
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year |  | $ 94 |  |
Expected contribution | [2] | 94 |  |
Rabbi Trust Associated With Deferred Compensation Plan [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Investments, Fair Value Disclosure |  | $ 6,689 | $ 6,734 |
FPU Medical Plan and Chesapeake OPRB [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined Benefit Plan, Number of Plans |  | 2 |  |
[1] | The pension plan is funded; therefore, benefit payments are expected to be paid out of the plan assets.
[2] | Benefit payments are expected to be paid out of our general funds.

X
- Definition Accumulated Other Comprehensive Income Loss Tax Effect + References No definition available. + Details
Name: | cpk_AccumulatedOtherComprehensiveIncomeLossTaxEffect
Namespace Prefix: | cpk_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Deferrals Rates After Deferral Period Ends Minimum + References No definition available. + Details
Name: | cpk_DeferralsRatesAfterDeferralPeriodEndsMinimum
Namespace Prefix: | cpk_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Deferred Compensation Employer Matching Contribution Rate + References No definition available. + Details
Name: | cpk_DeferredCompensationEmployerMatchingContributionRate
Namespace Prefix: | cpk_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan Pre Merger Regulatory Assets + References No definition available. + Details
Name: | cpk_DefinedBenefitPlanPreMergerRegulatoryAssets
Namespace Prefix: | cpk_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Defined Contribution Plan, Eligibility Threshold, Requisite Service Period + References No definition available. + Details
Name: | cpk_DefinedContributionPlanEligibilityThresholdRequisiteServicePeriod
Namespace Prefix: | cpk_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Contribution Plan Maximum Employer Contribution As Percentage Of Eligible Compensation + References No definition available. + Details
Name: | cpk_DefinedContributionPlanMaximumEmployerContributionAsPercentageOfEligibleCompensation
Namespace Prefix: | cpk_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Deferral rate employees can make + References No definition available. + Details
Name: | cpk_EmployeeDeferralRate
Namespace Prefix: | cpk_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Employee Minimum Age To Participate Under Defined Contribution Plan + References No definition available. + Details
Name: | cpk_EmployeeMinimumAgeToParticipateUnderDefinedContributionPlan
Namespace Prefix: | cpk_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Expected amortization of pre merger regulatory asset. + References No definition available. + Details
Name: | cpk_ExpectedAmortizationOfPreMergerRegulatoryAsset
Namespace Prefix: | cpk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Merger related costs allowed to be recovered in future rates. + References No definition available. + Details
Name: | cpk_MergerRelatedCostsAllowedToBeRecoveredInFutureRates
Namespace Prefix: | cpk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number Of Years to Collect Benefits + References No definition available. + Details
Name: | cpk_NumberOfYearstoCollectBenefits
Namespace Prefix: | cpk_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Plans + References No definition available. + Details
Name: | cpk_NumberofPlans
Namespace Prefix: | cpk_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of Sub Plans + References No definition available. + Details
Name: | cpk_NumberofSubPlans
Namespace Prefix: | cpk_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate number of common shares reserved for future issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The value of a trust established to hold the stock of an employee compensation and benefits plan as of the balance sheet date. + References No definition available. + Details
Name: | us-gaap_CompensationAndBenefitsTrust
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Minimum period the individual is required to perform services to be fully vested under the deferred compensation arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 710 -SubTopic 10 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6409961&loc=d3e20487-108367 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_DeferredCompensationArrangementWithIndividualRequisiteServicePeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of transition asset (obligation) recognized in net periodic benefit (cost) credit of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(6) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(6) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAmortizationOfTransitionAssetObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of benefits for defined benefit plan expected to be paid in next fiscal year following latest fiscal year. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of contributions expected to be received by defined benefit plan from employer in next fiscal year following latest fiscal year. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of funded (unfunded) status of defined benefit plan, measured as difference between fair value of plan assets and benefit obligation. Includes, but is not limited to, overfunded (underfunded) status. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109237824&loc=d3e1703-114919 + Details
Name: | us-gaap_DefinedBenefitPlanFundedStatusOfPlan
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Assumed rate, for next fiscal year, based on annual change in cost of health care cost benefits used to measure expected cost of benefits covered by defined benefit postretirement plan. Factors include, but are not limited to, estimate of health care inflation, change in health care utilization or delivery pattern, technological advances, and change in health status of participant. Excludes factors for change in composition of plan population by age and dependency status. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of discretionary contributions made by an employer to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage employer matches of the employee's percentage contribution matched. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of employer's matching contributions to a defined contribution plan that vests in a given year. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployersMatchingContributionAnnualVestingPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258 + Details
Name: | us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=cpk_ChesapeakePensionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=cpk_FloridaPublicUtilitiesCompanyPensionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=cpk_ChesapeakePensionSerpMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=cpk_RetirementMedicalBenefitsPlansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=cpk_ChesapeakePostretirementPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=cpk_FloridaPublicUtilitiesCompanyMedicalPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=cpk_RabbiTrustAssociatedWithDeferredCompensationPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanNameAxis=cpk_FPUMedicalPlanandChesapeakeOPRBMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |