-- None. No documentation exists for this element. --

No definition available.

Name:	thff_FinancingReceivableAbstract
Namespace Prefix:	thff_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Recorded Investment in financing receivables.

+ References

No definition available.

+ Details

Name:	thff_FinancingReceivableRecordedInvestment
Namespace Prefix:	thff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The balance of financing receivables that were acquired with deteriorated credit quality.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The valuation allowance for financing receivables acquired with deteriorated credit quality.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

+ Details

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- Details

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Allowance for Loan Losses (Details 1) - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
Ending Balance Attributable to Loans
Individually evaluated for impairment	$ 1,332		$ 1,911
Collectively evaluated for impairment	18,314		16,648
Acquired with deteriorated credit quality	215		280
Ending Balance	19,861	$ 19,351	18,839	$ 18,255	$ 20,408	$ 20,068
Loans
Individually evaluated for impairment	16,024		14,606
Collectively evaluated for impairment	1,767,820		1,767,701
Acquired with deteriorated credit quality	5,895		6,518
Total	1,789,739		1,788,825
Commercial
Ending Balance Attributable to Loans
Individually evaluated for impairment	1,305		1,911
Collectively evaluated for impairment	9,411		8,733
Acquired with deteriorated credit quality	215		271
Ending Balance	10,931	10,818	10,915	10,850	12,453	12,450
Loans
Individually evaluated for impairment	15,767		14,573
Collectively evaluated for impairment	1,054,233		1,030,949
Acquired with deteriorated credit quality	4,291		4,887
Total	1,074,291		1,050,409
Residential
Ending Balance Attributable to Loans
Individually evaluated for impairment	27		0
Collectively evaluated for impairment	1,733		1,365
Acquired with deteriorated credit quality	0		9
Ending Balance	1,760	1,622	1,374	1,374	1,581	1,585
Loans
Individually evaluated for impairment	257		33
Collectively evaluated for impairment	444,548		468,872
Acquired with deteriorated credit quality	1,604		1,631
Total	446,409		470,536
Consumer
Ending Balance Attributable to Loans
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	4,678		4,370
Acquired with deteriorated credit quality	0		0
Ending Balance	4,678	4,494	4,370	3,769	3,864	3,650
Loans
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	269,039		267,880
Acquired with deteriorated credit quality	0		0
Total	269,039		267,880
Unallocated
Ending Balance Attributable to Loans
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	2,492		2,180
Acquired with deteriorated credit quality	0		0
Ending Balance	$ 2,492	$ 2,417	$ 2,180	$ 2,262	$ 2,510	$ 2,383