Acquired Loans - Components of the Allowance for Loan Losses on Acquired Loans (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Allowance for Loan and Lease Losses [Roll Forward]
Balance at beginning of period		$ 815	$ 1,231
FASB ASU 2016-13 adoption adjustment		$ (815)
Net (charge-offs) recoveries			(458)
Provision for loan losses, acquired loans	[1]		42
Balance at end of period			$ 815

[1] Effective January 1, 2020, Trustmark adopted FASB ASU 2016-13 using the modified retrospective approach. Therefore, prior period balances are presented under legacy GAAP and may not be comparable to current period presentation.