Contingencies - Summary of Changes in ACL on Off-balance Sheet Credit Exposures (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Balance at beginning of period		$ 35,623	$ 38,572
PCL, off-balance sheet credit exposures	[1],[2]	(1,106)	(9,367)
Balance at end of period		$ 34,517	$ 29,205

[1] During the second quarter of 2021, Trustmark reclassified its credit loss expense related to off-balance sheet credit exposures from noninterest expense to PCL, off-balance sheet credit exposures. Prior periods have been reclassified accordingly.

[2] During the second quarter of 2021, Trustmark reclassified its credit loss expense on off-balance sheet credit exposures from noninterest expense to PCL, off-balance sheet credit exposures. The prior period has been reclassified accordingly.