Acquired Loans - Schedule of Covered and Noncovered Acquired Loans by Type (Details) - USD ($) $ in Thousands	Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 272,247		$ 390,411
Less allowance for loan losses, acquired loans	11,397		11,992	$ 12,059	$ 9,636
Noncovered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	268,633		372,711
Less allowance for loan losses, acquired loans	11,312		11,259	10,541	7,249
Net acquired loans	257,321		361,452
Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	3,614	[1]	17,700
Less allowance for loan losses, acquired loans	85	[1]	733	$ 1,518	$ 2,387
Net acquired loans	3,529	[1]	16,967
Construction, Land Development and Other Land [Member] | Noncovered Loans [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	20,850		41,623
Construction, Land Development and Other Land [Member] | Covered Loans [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	0	[1]	1,021
Secured by 1-4 Family Residential Properties [Member] | Noncovered Loans [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	65,926		86,950
Secured by 1-4 Family Residential Properties [Member] | Covered Loans [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	3,614	[1]	10,058
Secured by Nonfarm, Nonresidential Properties [Member] | Noncovered Loans [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	103,820		135,626
Secured by Nonfarm, Nonresidential Properties [Member] | Covered Loans [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	0	[1]	4,638
Other Real Estate Secured [Member] | Noncovered Loans [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	19,010		23,860
Other Real Estate Secured [Member] | Covered Loans [Member] | Loans Secured by Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	0	[1]	1,286
Commercial and Industrial Loans [Member] | Noncovered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	36,896		55,075
Commercial and Industrial Loans [Member] | Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	0	[1]	624
Consumer Loans [Member] | Noncovered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	3,365		5,641
Consumer Loans [Member] | Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	0	[1]	0
Other Loans [Member] | Noncovered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	18,766		23,936
Other Loans [Member] | Covered Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Acquired loans	$ 0	[1]	$ 73

[1] Trustmark’s loss share agreement with the FDIC covering the acquired covered loans other than loans secured by 1-4 family residential property expired on June 30, 2016. Trustmark’s loss share agreement with the FDIC covering the acquired covered loans secured by 1-4 family residential property will expire in 2021. Effective July 1, 2016, all acquired covered loans, excluding the acquired covered loans secured by 1-4 family residential property, were reclassified to acquired noncovered loans.