2.2.0.7 true Postretirement Benefit Plans (Details) (USD $) 0607 - Disclosure - Postretirement Benefit Plans (Details) true false false false 1 USD false false 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 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 2 USD false false 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 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 3 USD true false false false Retirement Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi hcbk_RetirementPlansMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 4 USD true false false false Retirement Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi hcbk_RetirementPlansMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 5 USD true false false false Retirement Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi hcbk_RetirementPlansMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 6 USD true false false false Retirement Plans [Member] us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis xbrldi http://xbrl.org/2006/xbrldi hcbk_RetirementPlansMember us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 7 USD true false false false Other Benefits [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 8 USD true false false false Other Benefits [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 9 USD true false false false Other Benefits [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 10 USD true false false false Other Benefits [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 $ 5 Components of the net periodic expense for postretirement benefit plans 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 true 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 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 true true false false 1018000 1018000 true false false 4 true true false false 1003000 1003000 true false false 5 true true false false 3054000 3054000 true false false 6 true true false false 3009000 3009000 true false false 7 true true false false 152000 152000 true false false 8 true true false false 234000 234000 true false false 9 true true false false 456000 456000 true false false 10 true true false false 702000 702000 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 true false false 2076000 2076000 true false false 4 false true false false 1863000 1863000 true false false 5 false true false false 6228000 6228000 true false false 6 false true false false 5589000 5589000 true false false 7 false true false false 476000 476000 true false false 8 false true false false 529000 529000 true false false 9 false true false false 1428000 1428000 true false false 10 false true false false 1587000 1587000 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 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 true false false -2914000 -2914000 true false false 4 false true false false -1939000 -1939000 true false false 5 false true false false -8742000 -8742000 true false false 6 false true false false -5817000 -5817000 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 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: 4 us-gaap_AdjustmentForAmortizationAbstract 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 true 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 xbrli:stringItemType string No definition available. false 10 Net loss 5 us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses 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 true false false 680000 680000 true false false 4 false true false false 824000 824000 true false false 5 false true false false 2040000 2040000 true false false 6 false true false false 2472000 2472000 true false false 7 false true false false 66000 66000 true false false 8 false true false false 128000 128000 true false false 9 false true false false 198000 198000 true false false 10 false true false false 384000 384000 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 false 11 Unrecognized prior service cost 5 us-gaap_DefinedBenefitPlanAmortizationOfNetPriorServiceCostCredit 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 true false false 85000 85000 true false false 4 false true false false 85000 85000 true false false 5 false true false false 255000 255000 true false false 6 false true false false 255000 255000 true false false 7 false true false false -391000 -391000 true false false 8 false true false false -391000 -391000 true false false 9 false true false false -1173000 -1173000 true false false 10 false true false false -1173000 -1173000 true false false xbrli:monetaryItemType monetary The amounts in accumulated other comprehensive income related to prior service cost or credit expected to be recognized as components of net periodic benefit cost over the next fiscal year that follows the most recent annual statement of financial position presented. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph s Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 158 -Paragraph 7 -Subparagraph d 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 true false false 945000 945000 true false false 4 false true false false 1836000 1836000 true false false 5 false true false false 2835000 2835000 true false false 6 false true false false 5508000 5508000 true false false 7 false true false false 303000 303000 true false false 8 false true false false 500000 500000 true false false 9 false true false false 909000 909000 true false false 10 false true false false 1500000 1500000 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 Postretirement Benefit Plans (Textuals) [Abstract] 1 hcbk_PostretirementBenefitPlansTextualsAbstract hcbk false na duration Postretirement Benefit Plans. 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 true 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 xbrli:stringItemType string Postretirement Benefit Plans. false 14 Contribution to pension plan 2 us-gaap_DefinedBenefitPlanContributionsByEmployer us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 true true false false 0 0 false false false 2 true true false false 35000000 35000000 false false false 3 false false false false 0 0 true 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 xbrli:monetaryItemType monetary The amount of contributions made by the employer. 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