2.2.0.7 true Pensions and Postretirement Benefits Other Than Pensions (Details) (USD $) 0611 - Disclosure - Pensions and Postretirement Benefits Other Than Pensions (Details) true false In Millions false false 1 USD false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 2 USD false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 3 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 4 USD true false false false Other than Pensions [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 5 USD true false false false Other than Pensions [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 6 USD true false false false Other than Pensions [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 7 USD true false false false Other than Pensions [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 8 USD true false false false Other Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi gr_OtherPostretirementBenefitPlanDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 9 USD true false false false Other Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi gr_OtherPostretirementBenefitPlanDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 10 USD true false false false Other Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi gr_OtherPostretirementBenefitPlanDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 11 USD true false false false Other Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi gr_OtherPostretirementBenefitPlanDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 12 USD true false false false U.S. Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 13 USD true false false false U.S. Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 14 USD true false false false U.S. Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 15 USD true false false false U.S. Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 16 USD true false false false U.K. Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ForeignPensionPlansDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 17 USD true false false false U.K. Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ForeignPensionPlansDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 18 USD true false false false U.K. Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ForeignPensionPlansDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 19 USD true false false false U.K. Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ForeignPensionPlansDefinedBenefitMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ 5 Net periodic benefit cost for pensions 3 us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false 14 false false false false 0 0 true false false 15 false false false false 0 0 true false false 16 false false false false 0 0 true false false 17 false false false false 0 0 true false false 18 false false false false 0 0 true false false 19 false false false false 0 0 true false false xbrli:stringItemType string No definition available. false 6 Service cost 4 us-gaap_DefinedBenefitPlanServiceCost us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 true true false false 200000 0.2 true false false 5 true true false false 300000 0.3 true false false 6 true true false false 600000 0.6 true false false 7 true true false false 700000 0.7 true false false 8 true true false false 1200000 1.2 true false false 9 true true false false 900000 0.9 true false false 10 true true false false 2400000 2.4 true false false 11 true true false false 1800000 1.8 true false false 12 true true false false 11400000 11.4 true false false 13 true true false false 11900000 11.9 true false false 14 true true false false 23100000 23.1 true false false 15 true true false false 21400000 21.4 true false false 16 true true false false 3600000 3.6 true false false 17 true true false false 3300000 3.3 true false false 18 true true false false 7700000 7.7 true false false 19 true true false false 7600000 7.6 true false false xbrli:monetaryItemType monetary The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph a, h false 7 Interest cost 4 us-gaap_DefinedBenefitPlanInterestCost us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false 4400000 4.4 true false false 5 false true false false 4400000 4.4 true false false 6 false true false false 8700000 8.7 true false false 7 false true false false 9700000 9.7 true false false 8 false true false false 1700000 1.7 true false false 9 false true false false 1800000 1.8 true false false 10 false true false false 3500000 3.5 true false false 11 false true false false 3200000 3.2 true false false 12 false true false false 42100000 42.1 true false false 13 false true false false 43000000 43.0 true false false 14 false true false false 84300000 84.3 true false false 15 false true false false 85900000 85.9 true false false 16 false true false false 9500000 9.5 true false false 17 false true false false 9500000 9.5 true false false 18 false true false false 19300000 19.3 true false false 19 false true false false 17800000 17.8 true false false xbrli:monetaryItemType monetary The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph a, h false 8 Expected return on plan assets 4 us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false -1800000 -1.8 true false false 9 false true false false -1400000 -1.4 true false false 10 false true false false -3500000 -3.5 true false false 11 false true false false -2500000 -2.5 true false false 12 false true false false -47900000 -47.9 true false false 13 false true false false -45300000 -45.3 true false false 14 false true false false -93800000 -93.8 true false false 15 false true false false -87100000 -87.1 true false false 16 false true false false -12700000 -12.7 true false false 17 false true false false -10600000 -10.6 true false false 18 false true false false -25900000 -25.9 true false false 19 false true false false -20300000 -20.3 true false false xbrli:monetaryItemType monetary An amount calculated as a basis for determining the extent of delayed recognition of the effects of changes in the fair value of assets. The expected return on plan assets is determined based on the expected long-term rate of return on plan assets and the market-related value of plan assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h false 9 Amortization of prior service cost 4 us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false -100000 -0.1 true false false 5 false true false false -100000 -0.1 true false false 6 false true false false -100000 -0.1 true false false 7 false true false false -100000 -0.1 true false false 8 false true false false 100000 0.1 true false false 9 false true false false 400000 0.4 true false false 10 false true false false 100000 0.1 true false false 11 false true false false 400000 0.4 true false false 12 false true false false 1700000 1.7 true false false 13 false true false false 1900000 1.9 true false false 14 false true false false 3500000 3.5 true false false 15 false true false false 3700000 3.7 true false false 16 false true false false -200000 -0.2 true false false 17 false true false false -200000 -0.2 true false false 18 false true false false -300000 -0.3 true false false 19 false true false false -300000 -0.3 true false false xbrli:monetaryItemType monetary The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h true 10 Gross periodic benefit cost 4 gr_DefinedBenefitPlanCostBeforeSettlementCurtailment gr false debit duration Defined benefit plan cost before settlement curtailment. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false true false false 3300000 3.3 true false false 11 false true false false 3500000 3.5 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false 14 false true false false 75500000 75.5 true false false 15 false true false false 76500000 76.5 true false false 16 false false false false 0 0 true false false 17 false false false false 0 0 true false false 18 false true false false 2100000 2.1 true false false 19 false true false false 8300000 8.3 true false false xbrli:monetaryItemType monetary Defined benefit plan cost before settlement curtailment. No authoritative reference available. false 11 Settlement (gain) loss 4 us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false true false false -400000 -0.4 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false 14 false false false false 0 0 true false false 15 false false false false 0 0 true false false 16 false false false false 0 0 true false false 17 false false false false 0 0 true false false 18 false false false false 0 0 true false false 19 false false false false 0 0 true false false xbrli:monetaryItemType monetary The amount of net (gain) loss recognized in net periodic benefit cost as a result of an irrevocable action that relieves the employer (or the plan) of primary responsibility for a benefit obligation and eliminates significant risks related to the obligation and the assets used to effect the settlement. Examples of transactions that constitute a settlement include (a) making lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and (b) purchasing nonparticipating annuity contracts to cover vested benefits. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 88 -Paragraph 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h true 12 Net periodic benefit cost 4 us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false 4500000 4.5 true false false 5 false true false false 4600000 4.6 true false false 6 false true false false 9200000 9.2 true false false 7 false true false false 10300000 10.3 true false false 8 false true false false 1600000 1.6 true false false 9 false true false false 2000000 2.0 true false false 10 false true false false 3300000 3.3 true false false 11 false true false false 3100000 3.1 true false false 12 false true false false 35500000 35.5 true false false 13 false true false false 35800000 35.8 true false false 14 false true false false 75500000 75.5 true false false 15 false true false false 76500000 76.5 true false false 16 false true false false 900000 0.9 true false false 17 false true false false 4200000 4.2 true false false 18 false true false false 2100000 2.1 true false false 19 false true false false 8300000 8.3 true false false xbrli:monetaryItemType monetary The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain or loss, prior service cost or credit, transition asset or obligation, and gain or loss due to settlements or curtailments). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h true 13 Weighted-average assumptions used to determine net periodic benefit cost 3 us-gaap_DefinedBenefitPlanWeightedAverageAssumptionsUsedInCalculatingNetPeriodicBenefitCostAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false 14 false false false false 0 0 true false false 15 false false false false 0 0 true false false 16 false false false false 0 0 true false false 17 false false false false 0 0 true false false 18 false false false false 0 0 true false false 19 false false false false 0 0 true false false xbrli:stringItemType string No definition available. false 14 Discount rate 4 us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false true false false 0.0555 0.0555 true false false 7 false true false false 0.0638 0.0638 true false false 8 false true false false 0.0575 0.0575 true false false 9 false true false false 0.0617 0.0617 true false false 10 false true false false 0.0575 0.0575 true false false 11 false true false false 0.0617 0.0617 true false false 12 false true false false 0.059 0.059 true false false 13 false true false false 0.0647 0.0647 true false false 14 false true false false 0.059 0.059 true false false 15 false true false false 0.0647 0.0647 true false false 16 false true false false 0.0588 0.0588 true false false 17 false true false false 0.0588 0.0588 true false false 18 false true false false 0.0588 0.0588 true false false 19 false true false false 0.0588 0.0588 true false false us-types:percentItemType pure The interest rate used to adjust for the time value of money. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph j false 15 Expected long-term rate of return on assets 4 us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false 0.0832 0.0832 true false false 9 false true false false 0.0812 0.0812 true false false 10 false true false false 0.0832 0.0832 true false false 11 false true false false 0.0812 0.0812 true false false 12 false true false false 0.0875 0.0875 true false false 13 false true false false 0.0875 0.0875 true false false 14 false true false false 0.0875 0.0875 true false false 15 false true false false 0.0875 0.0875 true false false 16 false true false false 0.085 0.085 true false false 17 false true false false 0.085 0.085 true false false 18 false true false false 0.085 0.085 true false false 19 false true false false 0.085 0.085 true false false us-types:percentItemType pure An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph j false 16 Rate of compensation increase 4 us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false 0.0338 0.0338 true false false 9 false true false false 0.0331 0.0331 true false false 10 false true false false 0.0338 0.0338 true false false 11 false true false false 0.0331 0.0331 true false false 12 false true false false 0.041 0.041 true false false 13 false true false false 0.041 0.041 true false false 14 false true false false 0.041 0.041 true false false 15 false true false false 0.041 0.041 true false false 16 false true false false 0.0375 0.0375 true false false 17 false true false false 0.0375 0.0375 true false false 18 false true false false 0.0375 0.0375 true false false 19 false true false false 0.0375 0.0375 true false false us-types:percentItemType pure Expected rate of compensation increases (for pay-related plans). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph j false 17 Net periodic postretirement benefit cost for other than pensions 3 gr_NetPeriodicBenefitCostForOtherThanPensionsAbstract gr false na duration Net periodic benefit cost for other than pensions. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false 14 false false false false 0 0 true false false 15 false false false false 0 0 true false false 16 false false false false 0 0 true false false 17 false false false false 0 0 true false false 18 false false false false 0 0 true false false 19 false false false false 0 0 true false false xbrli:stringItemType string Net periodic benefit cost for other than pensions. false 18 Service cost 4 us-gaap_DefinedBenefitPlanServiceCost us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false 200000 0.2 true false false 5 false true false false 300000 0.3 true false false 6 false true false false 600000 0.6 true false false 7 false true false false 700000 0.7 true false false 8 false true false false 1200000 1.2 true false false 9 false true false false 900000 0.9 true false false 10 false true false false 2400000 2.4 true false false 11 false true false false 1800000 1.8 true false false 12 false true false false 11400000 11.4 true false false 13 false true false false 11900000 11.9 true false false 14 false true false false 23100000 23.1 true false false 15 false true false false 21400000 21.4 true false false 16 false true false false 3600000 3.6 true false false 17 false true false false 3300000 3.3 true false false 18 false true false false 7700000 7.7 true false false 19 false true false false 7600000 7.6 true false false xbrli:monetaryItemType monetary The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph a, h false 19 Interest cost 4 us-gaap_DefinedBenefitPlanInterestCost us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false 4400000 4.4 true false false 5 false true false false 4400000 4.4 true false false 6 false true false false 8700000 8.7 true false false 7 false true false false 9700000 9.7 true false false 8 false true false false 1700000 1.7 true false false 9 false true false false 1800000 1.8 true false false 10 false true false false 3500000 3.5 true false false 11 false true false false 3200000 3.2 true false false 12 false true false false 42100000 42.1 true false false 13 false true false false 43000000 43.0 true false false 14 false true false false 84300000 84.3 true false false 15 false true false false 85900000 85.9 true false false 16 false true false false 9500000 9.5 true false false 17 false true false false 9500000 9.5 true false false 18 false true false false 19300000 19.3 true false false 19 false true false false 17800000 17.8 true false false xbrli:monetaryItemType monetary The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph a, h false 20 Amortization of prior service cost 4 us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false -100000 -0.1 true false false 5 false true false false -100000 -0.1 true false false 6 false true false false -100000 -0.1 true false false 7 false true false false -100000 -0.1 true false false 8 false true false false 100000 0.1 true false false 9 false true false false 400000 0.4 true false false 10 false true false false 100000 0.1 true false false 11 false true false false 400000 0.4 true false false 12 false true false false 1700000 1.7 true false false 13 false true false false 1900000 1.9 true false false 14 false true false false 3500000 3.5 true false false 15 false true false false 3700000 3.7 true false false 16 false true false false -200000 -0.2 true false false 17 false true false false -200000 -0.2 true false false 18 false true false false -300000 -0.3 true false false 19 false true false false -300000 -0.3 true false false xbrli:monetaryItemType monetary The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h false 21 Amortization of actuarial loss 4 us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses us-gaap true credit duration No definition available. false false false false false false false false false false true negatedtotal false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false true false false 400000 0.4 true false false 9 false true false false 300000 0.3 true false false 10 false true false false 800000 0.8 true false false 11 false true false false 600000 0.6 true false false 12 false true false false 28200000 28.2 true false false 13 false true false false 24300000 24.3 true false false 14 false true false false 58400000 58.4 true false false 15 false true false false 52600000 52.6 true false false 16 false true false false 700000 0.7 true false false 17 false true false false 2200000 2.2 true false false 18 false true false false 1300000 1.3 true false false 19 false true false false 3500000 3.5 true false false xbrli:monetaryItemType monetary The amount of gains or losses recognized in net periodic benefit cost Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h true 22 Net periodic benefit cost 4 us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 true true false false 4500000 4.5 true false false 5 true true false false 4600000 4.6 true false false 6 true true false false 9200000 9.2 true false false 7 true true false false 10300000 10.3 true false false 8 true true false false 1600000 1.6 true false false 9 true true false false 2000000 2.0 true false false 10 true true false false 3300000 3.3 true false false 11 true true false false 3100000 3.1 true false false 12 true true false false 35500000 35.5 true false false 13 true true false false 35800000 35.8 true false false 14 true true false false 75500000 75.5 true false false 15 true true false false 76500000 76.5 true false false 16 true true false false 900000 0.9 true false false 17 true true false false 4200000 4.2 true false false 18 true true false false 2100000 2.1 true false false 19 true true false false 8300000 8.3 true false false xbrli:monetaryItemType monetary The total amount of net periodic benefit cost for defined benefit plans for the period. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain or loss, prior service cost or credit, transition asset or obligation, and gain or loss due to settlements or curtailments). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h true 23 Assumptions used to determine the net periodic postretirement benefit cost 3 gr_AssumptionsUsedToDetermineNetPeriodicPostretirementBenefitCostAbstract gr false na duration Assumptions used to determine the net periodic postretirement benefit cost. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false 14 false false false false 0 0 true false false 15 false false false false 0 0 true false false 16 false false false false 0 0 true false false 17 false false false false 0 0 true false false 18 false false false false 0 0 true false false 19 false false false false 0 0 true false false xbrli:stringItemType string Assumptions used to determine the net periodic postretirement benefit cost. false 24 Discount rate 4 us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false true false false 0.0555 0.0555 true false false 7 false true false false 0.0638 0.0638 true false false 8 false true false false 0.0575 0.0575 true false false 9 false true false false 0.0617 0.0617 true false false 10 false true false false 0.0575 0.0575 true false false 11 false true false false 0.0617 0.0617 true false false 12 false true false false 0.059 0.059 true false false 13 false true false false 0.0647 0.0647 true false false 14 false true false false 0.059 0.059 true false false 15 false true false false 0.0647 0.0647 true false false 16 false true false false 0.0588 0.0588 true false false 17 false true false false 0.0588 0.0588 true false false 18 false true false false 0.0588 0.0588 true false false 19 false true false false 0.0588 0.0588 true false false us-types:percentItemType pure The interest rate used to adjust for the time value of money. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph j false 25 Defined benefit plan health care cost trend rate assured for next fiscal year 4 us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedForNextFiscalYear us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0.073 0.073 false false false 2 false true false false 0.078 0.078 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false 14 false false false false 0 0 true false false 15 false false false false 0 0 true false false 16 false false false false 0 0 true false false 17 false false false false 0 0 true false false 18 false false false false 0 0 true false false 19 false false false false 0 0 true false false us-types:percentItemType pure The assumed health care cost trend rate for the next year used to measure the expected cost of benefits covered by the plan (gross eligible charges). This is based upon the annual rate of change in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph l false 26 Defined benefit plan ultimate health care cost trend rate 4 us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0.05 0.05 false false false 2 false true false false 0.05 0.05 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false 14 false false false false 0 0 true false false 15 false false false false 0 0 true false false 16 false false false false 0 0 true false false 17 false false false false 0 0 true false false 18 false false false false 0 0 true false false 19 false false false false 0 0 true false false us-types:percentItemType pure The ultimate trend rate for health care costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph l false 27 Defined benefit plan year that rate reaches ultimate trend rate 4 us-gaap_DefinedBenefitPlanYearThatRateReachesUltimateTrendRate us-gaap true na instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 2015 false false false 2 false false false false 0 0 2015 false false false 3 false false false false 0 0 2015 2015 false false false 4 false false false false 0 0 true false false 5 false false false false 0 0 true false false 6 false false false false 0 0 true false false 7 false false false false 0 0 true false false 8 false false false false 0 0 true false false 9 false false false false 0 0 true false false 10 false false false false 0 0 true false false 11 false false false false 0 0 true false false 12 false false false false 0 0 true false false 13 false false false false 0 0 true false false 14 false false false false 0 0 true false false 15 false false false false 0 0 true false false 16 false false false false 0 0 true false false 17 false false false false 0 0 true false false 18 false false false false 0 0 true false false 19 false false false false 0 0 true false false xbrli:gYearItemType positiveinteger The year when the ultimate health care cost trend rate is expected to be reached. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph l false 19 23 false HundredThousands UnKnown UnKnown false true