Mortgage Banking - Changes in the Reserve for Mortgage Loan Servicing Putback Expense (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Schedule of changes in the reserve for mortgage loan [Abstract]
Balance at beginning of period		$ 1,000	$ 1,130
Provision for putback expenses		0	105
Other	[1]	0	16
Balance at end of period		$ 1,000	$ 1,251

[1] Includes fair value adjustments for loans transferred due to underwriting issues as well as adjustments based on Trustmark’s mortgage loan servicing putback reserve analysis.