XML 57 R47.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Components of Net Periodic Benefit Cost (Details Textual) - USD ($) $ in Thousands | 9 Months Ended |
--- | --- | ---
Sep. 30, 2016 | Sep. 30, 2015 | Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefits Plan Estimated Future Employer Contributions In Next Fiscal Year |  |  | $ 2,700
Defined Benefit Plan, Expected Future Benefit Payments, Next Rolling Twelve Months |  |  | 1,100
Defined Contribution Plan Employer Accrued Discretionary Contribution Amount | $ 1,200 | $ 1,100 |
Post Retirement Health Benefits [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefits Plan Estimated Future Employer Contributions In Next Fiscal Year |  |  | $ 262
Defined Benefit Plan, Contributions by Employer | 151 |  |
Pension Plan [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Contributions by Employer | $ 2,100 |  |

X
- Definition Amount of potential discretionary contributions accrued to a defined contribution plan. + References No definition available. + Details
Name: | thff_DefinedContributionPlanEmployerAccruedDiscretionaryContributionAmount
Namespace Prefix: | thff_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of contributions made by the employer to defined benefit plans. + 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 (d)(5)(ii) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 60 -Section 35 -Paragraph 123 -Subparagraph B -URI http://asc.fasb.org/extlink&oid=64937487&loc=d3e36068-114959 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 30 -Section 35 -Paragraph 63 -Subparagraph B -URI http://asc.fasb.org/extlink&oid=64937038&loc=d3e12551-114930 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5)(iv)(01) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 from a defined benefit plan expected to be paid in the next rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextRollingTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of benefits from a defined benefit plan expected to be paid in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date. + 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 (f) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=thff_PostRetirementHealthBenefitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=thff_PensionBenefitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |