The total carrying value of acquired loans including covered and noncovered.

No definition available.

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Namespace Prefix:	trmk_
Data Type:	xbrli:monetaryItemType
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- Definition

Reserve for loans impairments recorded after acquisition as a result of current information and events which result in it being probable that estimated cash flows will be less than previously expected or because actual cash flows are less than cash flows previously expected. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(2)

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 15

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=27045933&loc=d3e13503-111538

+ Details

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

- Definition

The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 15

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=27045933&loc=d3e13503-111538

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

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

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Acquired Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Financing Receivable, Allowance for Credit Losses [Line Items]
Less allowance for loan losses, acquired loans	$ 12,185	$ 12,059	$ 11,949	$ 9,636
Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	400,528	525,783
Less allowance for loan losses, acquired loans	11,417	10,541
Net acquired loans	389,111	515,242
Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	18,645	23,626
Less allowance for loan losses, acquired loans	768	1,518
Net acquired loans	17,877	22,108
Construction, Land Development and Other Land [Member] \| Loans Secured by Real Estate [Member] \| Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	45,299	58,309
Construction, Land Development and Other Land [Member] \| Loans Secured by Real Estate [Member] \| Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	966	1,197
Secured by 1-4 Family Residential Properties [Member] \| Loans Secured by Real Estate [Member] \| Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	96,870	116,920
Secured by 1-4 Family Residential Properties [Member] \| Loans Secured by Real Estate [Member] \| Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	10,546	13,180
Secured by Nonfarm, Nonresidential Properties [Member] \| Loans Secured by Real Estate [Member] \| Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	146,614	202,323
Secured by Nonfarm, Nonresidential Properties [Member] \| Loans Secured by Real Estate [Member] \| Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	5,363	7,672
Other Real Estate Secured [Member] \| Loans Secured by Real Estate [Member] \| Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	23,816	27,813
Other Real Estate Secured [Member] \| Loans Secured by Real Estate [Member] \| Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	1,511	1,096
Commercial and Industrial Loans [Member] \| Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	57,748	88,256
Commercial and Industrial Loans [Member] \| Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	205	277
Consumer Loans [Member] \| Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	6,295	9,772
Consumer Loans [Member] \| Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	0	0
Other Loans [Member] \| Noncovered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	23,886	22,390
Other Loans [Member] \| Covered [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 54	$ 204