XML 93 R78.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Employee Benefit Plans - Assumptions in Benefit Plans (Details) | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Weighted-average assumptions used to determine projected pension benefit obligations |  |  |
Discount rate (as a percent) | 3.85% | 4.30% | 4.25%
Health care cost trend rate for medical benefits assumed for next year (pre-65) | 7.50% | 7.50% | 5.50%
Health care cost trend rate for medical benefits assumed for next year (post-65) | 5.75% | 5.00% | 5.50%
Ultimate trend rate (pre-65) | 4.50% | 4.50% | 4.50%
Ultimate trend rate (post-65) | 4.50% | 4.50% | 4.50%
Year that the rate reaches the ultimate trend rate (pre-65) | 2030 | 2023 | 2018
Year that the rate reaches the ultimate trend rate (post-65) | 2023 | 2018 | 2018
Beginning Discount Rate | 3.85% | 4.25% | 4.00%

X
- Definition The interest rate used to adjust for the time value of money for the plan at beginning of year. + References No definition available. + Details
Name: | cog_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRateBeginningOfYear
Namespace Prefix: | cog_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year, Post-65 + References No definition available. + Details
Name: | cog_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYearPost65
Namespace Prefix: | cog_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year, Pre-65 + References No definition available. + Details
Name: | cog_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYearPre65
Namespace Prefix: | cog_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Ultimate Health Care Cost Trend Rate, Post-65 + References No definition available. + Details
Name: | cog_DefinedBenefitPlanUltimateHealthCareCostTrendRatePost65
Namespace Prefix: | cog_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Ultimate Health Care Cost Trend Rate, Pre-65 + References No definition available. + Details
Name: | cog_DefinedBenefitPlanUltimateHealthCareCostTrendRatePre65
Namespace Prefix: | cog_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate, Post-65 + References No definition available. + Details
Name: | cog_DefinedBenefitPlanYearHealthCareCostTrendRateReachesUltimateTrendRatePost65
Namespace Prefix: | cog_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate, Pre-65 + References No definition available. + Details
Name: | cog_DefinedBenefitPlanYearHealthCareCostTrendRateReachesUltimateTrendRatePre65
Namespace Prefix: | cog_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingBenefitObligationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration