Defined Benefit and Other Postretirement Benefits - Estimated Future Benefit Payments and Other Disclosures (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Supplemental Retirement Plan [Member]
Estimated future benefit payments [Abstract]
2023	$ 3,963
2024	3,977
2025	3,838
2026	3,785
2027	3,596
2028 - 2032	16,536
Trustmark Corporation Pension Plan for Certain Employees of Acquired Financial Institutions [Member] \| Trustmark Capital Accumulation Plan [Member]
Estimated future benefit payments [Abstract]
2023	1,864
2024	1,068
2025	556
2026	583
2027	639
2028 - 2032	$ 1,565

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- Definition

Amount of benefit for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920

+ Details

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- Definition

Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year.

+ References

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- Definition

Amount of benefit for defined benefit plan expected to be paid in fifth fiscal year following current fiscal year.

+ References

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Amount of benefit for defined benefit plan expected to be paid in fourth fiscal year following current fiscal year.

+ References

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Amount of benefit for defined benefit plan expected to be paid in third fiscal year following current fiscal year.

+ References

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Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year.

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