The carrying value of acquired loans during the period.

No definition available.

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Namespace Prefix:	trmk_
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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=82894903&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=82894507&loc=d3e13503-111538

+ Details

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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=82894903&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=82894507&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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- 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 - Schedule of Acquired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 261,517	$ 272,247
Less allowance for loan losses, acquired loans	4,079	11,397	$ 11,992	$ 12,059
Net acquired loans	257,438	260,850
Construction, Land Development and Other Land [Member] \| Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	23,586	20,850
Secured by 1-4 Family Residential Properties [Member] \| Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	61,751	69,540
Secured by Nonfarm, Nonresidential Properties [Member] \| Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	114,694	103,820
Other Real Estate Secured [Member] \| Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	16,746	19,010
Commercial and Industrial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	31,506	36,896
Consumer Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	2,600	3,365
Other Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 10,634	$ 18,766