Shareholders' Equity (Tables)

12 Months Ended

Dec. 31, 2011

Shareholders' Equity [Abstract]

Table of actual regulatory capital amounts and ratios

Trustmark's and TNB's actual regulatory capital amounts and ratios are presented in the table below ($ in thousands):

											Minimum Regulatory
	Actual					Minimum Regulatory					Provision to be
	Regulatory Capital					Capital Required					Well-Capitalized
	Amount		Ratio			Amount		Ratio			Amount		Ratio
At December 31, 2011:
Total Capital (to Risk Weighted Assets)
Trustmark Corporation	$	1,096,213		16.67	%	$	526,156		8.00	%		n/a		n/a
Trustmark National Bank		1,057,932		16.28	%		519,709		8.00	%	$	649,636		10.00	%
Tier 1 Capital (to Risk Weighted Assets)
Trustmark Corporation	$	974,034		14.81	%	$	263,078		4.00	%		n/a		n/a
Trustmark National Bank		938,122		14.44	%		259,855		4.00	%	$	389,782		6.00	%
Tier 1 Capital (to Average Assets)
Trustmark Corporation	$	974,034		10.43	%	$	280,162		3.00	%		n/a		n/a
Trustmark National Bank		938,122		10.18	%		276,502		3.00	%	$	460,837		5.00	%
At December 31, 2010:
Total Capital (to Risk Weighted Assets)
Trustmark Corporation	$	1,051,933		15.77	%	$	533,774		8.00	%		n/a		n/a
Trustmark National Bank		1,014,219		15.40	%		526,894		8.00	%	$	658,617		10.00	%
Tier 1 Capital (to Risk Weighted Assets)
Trustmark Corporation	$	918,600		13.77	%	$	266,887		4.00	%		n/a		n/a
Trustmark National Bank		883,549		13.42	%		263,447		4.00	%	$	395,170		6.00	%
Tier 1 Capital (to Average Assets)
Trustmark Corporation	$	918,600		10.14	%	$	271,867		3.00	%		n/a		n/a
Trustmark National Bank		883,549		9.89	%		267,967		3.00	%	$	446,612		5.00	%

Components of accumulated other comprehensive income (loss) and the related tax effects

The following table presents the components of accumulated other comprehensive income (loss) and the related tax effects allocated to each component for the years ended December 31, 2011, 2010 and 2009 ($ in thousands):

							Accumaulated
							Other
							Comprehensive
	Before-Tax			Tax			Income
	Amount			Effect			(Loss)
Balance, January 1, 2009	$	(23,800	)	$	9,083		$	(14,717	)
Unrealized gains on available for sale securities:
Unrealized holding gains arising during period		27,639			(10,572	)		17,067
Less: adjustment for net gains realized in net income		(5,467	)		2,091			(3,376	)
Pension and other postretirement benefit plans:
Net change in prior service cost arising during the period		(1,885	)		721			(1,164	)
Net decrease in loss arising during the period		917			(351	)		566
Balance, December 31, 2009		(2,596	)		972			(1,624	)
Unrealized gains on available for sale securities:
Unrealized holding losses arising during period		(15,431	)		5,902			(9,529	)
Less: adjustment for net gains realized in net income		(2,329	)		891			(1,438	)
Pension and other postretirement benefit plans:
Net change in prior service cost arising during the period		123			(47	)		76
Net decrease in loss arising during the period		1,764			(675	)		1,089
Balance, December 31, 2010		(18,469	)		7,043			(11,426	)
Unrealized gains on available for sale securities:
Unrealized holding gains arising during period		39,636			(15,161	)		24,475
Less: adjustment for net gains realized in net income		(80	)		31			(49	)
Pension and other postretirement benefit plans:
Net change in prior service cost arising during the period		(957	)		366			(591	)
Net increase in loss arising during the period		(15,041	)		5,753			(9,288	)
Balance, December 31, 2011	$	5,089		$	(1,968	)	$	3,121