The description of the unobservable input used to measure the fair value of assets at the end of the period.

No definition available.

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- Definition

Represents the provision for impaired loan losses.

+ References

No definition available.

+ Details

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Description of the inputs and valuation technique(s) used to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Amount of allowance for credit losses related to recorded investment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5212-111524

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- Definition

Carrying amount of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This does not include real estate assets taken in settlement of troubled loans through surrender or foreclosure.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.10(4))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

Amount of other deductions to real estate investments, excluding sales, for entities with a substantial portion of business acquiring and holding investment real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule III)

-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 28

-Article 12

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule III

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 970

-SubTopic 360

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-28.4)

-URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024

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Fair Value (Details Textual) (USD $)	3 Months Ended	12 Months Ended
Fair Value (Details Textual) (USD $)	Mar. 31, 2015	Dec. 31, 2013	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Valuation allowance for impaired loans	$ 1,557,000		$ 1,911,000
Provision for impaired loan losses	(385,000)thff_ProvisionForImpairedLoanLosses	(1,200,000)thff_ProvisionForImpairedLoanLosses
Other real estate owned	3,830,000us-gaap_OtherRealEstate		3,965,000us-gaap_OtherRealEstate
Commercial Real Estate [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	3,600,000
Residential Real Estate [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	1,200,000
State and Municipal Obligation [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	4,725,000		5,900,000
Fair Value Measurements, Valuation Techniques	Discounted cash flow		Discounted cash flow
Fair Value Measurements Unobservable Inputs	Discount rate Probability of default		Discount rate Probability of default
Impaired Loans \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	12,787,000		11,477,000
Valuation allowance for impaired loans	1,600,000		1,900,000
Fair Value Measurements, Valuation Techniques	Sales comparison/income approach		Sales comparison/income approach
Fair Value Measurements Unobservable Inputs	Discount rate for age of appraisal and market conditions		Discount rate for age of appraisal and market conditions
Other Real Estate
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Real estate, other deductions	1,100,000		1,100,000
Other Real Estate \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value	3,830,000		3,965,000
Other real estate owned	$ 4,800,000
Fair Value Measurements, Valuation Techniques	Sales comparison/income approach		Sales comparison/income approach
Fair Value Measurements Unobservable Inputs	Discount rate for age of appraisal and market conditions		Discount rate for age of appraisal and market conditions
Minimum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value inputs, discount rate	0.00%
Minimum [Member] \| State and Municipal Obligation [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value inputs, discount rate	3.05%		3.05%
Minimum [Member] \| Impaired Loans \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value inputs, discount rate	0.00%		0.00%
Minimum [Member] \| Other Real Estate \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value inputs, discount rate	5.00%		5.00%
Maximum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value inputs, discount rate	50.00%
Maximum [Member] \| State and Municipal Obligation [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value inputs, discount rate	5.50%		5.50%
Maximum [Member] \| Impaired Loans \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value inputs, discount rate	50.00%		50.00%
Maximum [Member] \| Other Real Estate \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value inputs, discount rate	20.00%		20.00%