Loans and Leases (Schedule of Modifications for Troubled Debt Restructurings) (Detail) (TDRs [Member], USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2013 Loans		Sep. 30, 2012 Loans		Sep. 30, 2013 Loans		Sep. 30, 2012 Loans
Financing Receivable Modifications [Line Items]
Number Of Loans	102		109		407		127
Pre-Modification Recorded Investment	$ 13,336,000		$ 7,635,000		$ 38,405,000		$ 12,958,000
Post-Modification Recorded Investment	13,336,000		7,635,000		38,405,000		12,958,000
Financial Effect Of Modification On Recorded Investment	0	[1]	0	[1]	0	[1]	0	[1]
Financial Effect Of Modification On Interest	45,000	[2]	0	[2]	(223,000)	[2]	0	[2]
Subsequently Defaulted [Member]
Financing Receivable Modifications [Line Items]
Number Of Contracts Subsequently Defaulted	56		6		119		9
Recorded Investment Subsequently Defaulted	5,915,000		1,191,000		15,295,000		2,531,000
Originated Loans And Leases [Member]
Financing Receivable Modifications [Line Items]
Number Of Loans	99		87		386		97
Pre-Modification Recorded Investment	12,962,000		5,370,000		35,569,000		8,255,000
Post-Modification Recorded Investment	12,962,000		5,370,000		35,569,000		8,255,000
Financial Effect Of Modification On Recorded Investment	0	[1]	0	[1]	0	[1]	0	[1]
Financial Effect Of Modification On Interest	66,000	[2]	0	[2]	(159,000)	[2]	0	[2]
Originated Loans And Leases [Member] | Subsequently Defaulted [Member]
Financing Receivable Modifications [Line Items]
Number Of Contracts Subsequently Defaulted	53		5		111		8
Recorded Investment Subsequently Defaulted	5,849,000		817,000		14,692,000		2,157,000
Purchased Loans And Leases [Member]
Financing Receivable Modifications [Line Items]
Number Of Loans	3		22		21		30
Pre-Modification Recorded Investment	374,000		2,265,000		2,836,000		4,703,000
Post-Modification Recorded Investment	374,000		2,265,000		2,836,000		4,703,000
Financial Effect Of Modification On Recorded Investment	0	[1]	0	[1]	0	[1]	0	[1]
Financial Effect Of Modification On Interest	(21,000)	[2]	0	[2]	(64,000)	[2]	0	[2]
Purchased Loans And Leases [Member] | Subsequently Defaulted [Member]
Financing Receivable Modifications [Line Items]
Number Of Contracts Subsequently Defaulted	3		1		8		1
Recorded Investment Subsequently Defaulted	66,000		374,000		603,000		374,000
Commercial, Financial, And Agricultural [Member] | Combination Of Modification Types [Member]
Financing Receivable Modifications [Line Items]
Number Of Loans	1		0		2		0
Pre-Modification Recorded Investment	51,000		0		292,000		0
Post-Modification Recorded Investment	51,000		0		292,000		0
Financial Effect Of Modification On Recorded Investment	0	[1]	0	[1]	0	[1]	0	[1]
Financial Effect Of Modification On Interest	0	[2]	0	[2]	0	[2]	0	[2]
Commercial, Financial, And Agricultural [Member] | Others [Member]
Financing Receivable Modifications [Line Items]
Number Of Loans	6	[3]	6	[3]	29	[3]	8	[3]
Pre-Modification Recorded Investment	845,000	[3]	457,000	[3]	9,379,000	[3]	787,000	[3]
Post-Modification Recorded Investment	845,000	[3]	457,000	[3]	9,379,000	[3]	787,000	[3]
Financial Effect Of Modification On Recorded Investment	0	[1],[3]	0	[1],[3]	0	[1],[3]	0	[1],[3]
Financial Effect Of Modification On Interest	(6,000)	[2],[3]	0	[2],[3]	(6,000)	[2],[3]	0	[2],[3]
Commercial, Financial, And Agricultural [Member] | Subsequently Defaulted [Member]
Financing Receivable Modifications [Line Items]
Number Of Contracts Subsequently Defaulted	3		1		15		1
Recorded Investment Subsequently Defaulted	33,000		351,000		7,334,000		351,000
Real Estate - Construction [Member] | Combination Of Modification Types [Member]
Financing Receivable Modifications [Line Items]
Number Of Loans	0		0		0		0
Pre-Modification Recorded Investment	0		0		0		0
Post-Modification Recorded Investment	0		0		0		0
Financial Effect Of Modification On Recorded Investment	0	[1]	0	[1]	0	[1]	0	[1]
Financial Effect Of Modification On Interest	0	[2]	0	[2]	0	[2]	0	[2]
Real Estate - Construction [Member] | Others [Member]
Financing Receivable Modifications [Line Items]
Number Of Loans	0	[3]	2	[3]	2	[3]	2	[3]
Pre-Modification Recorded Investment	0	[3]	343,000	[3]	137,000	[3]	343,000	[3]
Post-Modification Recorded Investment	0	[3]	343,000	[3]	137,000	[3]	343,000	[3]
Financial Effect Of Modification On Recorded Investment	0	[1],[3]	0	[1],[3]	0	[1],[3]	0	[1],[3]
Financial Effect Of Modification On Interest	0	[2],[3]	0	[2],[3]	0	[2],[3]	0	[2],[3]
Real Estate - Construction [Member] | Subsequently Defaulted [Member]
Financing Receivable Modifications [Line Items]
Number Of Contracts Subsequently Defaulted	1		0		3		0
Recorded Investment Subsequently Defaulted	117,000		0		254,000		0
Real Estate Secured - Residential [Member] | Combination Of Modification Types [Member]
Financing Receivable Modifications [Line Items]
Number Of Loans	8		3		25		17
Pre-Modification Recorded Investment	1,313,000		230,000		3,815,000		4,213,000
Post-Modification Recorded Investment	1,313,000		230,000		3,815,000		4,213,000
Financial Effect Of Modification On Recorded Investment	0	[1]	0	[1]	0	[1]	0	[1]
Financial Effect Of Modification On Interest	51,000	[2]	0	[2]	(21,000)	[2]	0	[2]
Real Estate Secured - Residential [Member] | Others [Member]
Financing Receivable Modifications [Line Items]
Number Of Loans	37	[3]	57	[3]	136	[3]	59	[3]
Pre-Modification Recorded Investment	3,715,000	[3]	4,766,000	[3]	12,038,000	[3]	5,776,000	[3]
Post-Modification Recorded Investment	3,715,000	[3]	4,766,000	[3]	12,038,000	[3]	5,776,000	[3]
Financial Effect Of Modification On Recorded Investment	0	[1],[3]	0	[1],[3]	0	[1],[3]	0	[1],[3]
Financial Effect Of Modification On Interest	0	[2],[3]	0	[2],[3]	0	[2],[3]	0	[2],[3]
Real Estate Secured - Residential [Member] | Subsequently Defaulted [Member]
Financing Receivable Modifications [Line Items]
Number Of Contracts Subsequently Defaulted	17		4		30		7
Recorded Investment Subsequently Defaulted	862,000		641,000		2,152,000		1,981,000
Real Estate Secured - Commercial [Member] | Combination Of Modification Types [Member]
Financing Receivable Modifications [Line Items]
Number Of Loans	0		0		1		0
Pre-Modification Recorded Investment	0		0		1,436,000		0
Post-Modification Recorded Investment	0		0		1,436,000		0
Financial Effect Of Modification On Recorded Investment	0	[1]	0	[1]	0	[1]	0	[1]
Financial Effect Of Modification On Interest	0	[2]	0	[2]	(196,000)	[2]	0	[2]
Real Estate Secured - Commercial [Member] | Others [Member]
Financing Receivable Modifications [Line Items]
Number Of Loans	7	[3]	6	[3]	19	[3]	6	[3]
Pre-Modification Recorded Investment	7,066,000	[3]	1,539,000	[3]	9,565,000	[3]	1,539,000	[3]
Post-Modification Recorded Investment	7,066,000	[3]	1,539,000	[3]	9,565,000	[3]	1,539,000	[3]
Financial Effect Of Modification On Recorded Investment	0	[1],[3]	0	[1],[3]	0	[1],[3]	0	[1],[3]
Financial Effect Of Modification On Interest	0	[2],[3]	0	[2],[3]	0	[2],[3]	0	[2],[3]
Real Estate Secured - Commercial [Member] | Subsequently Defaulted [Member]
Financing Receivable Modifications [Line Items]
Number Of Contracts Subsequently Defaulted	4		1		7		1
Recorded Investment Subsequently Defaulted	4,640,000		199,000		5,087,000		199,000
Consumer [Member] | Combination Of Modification Types [Member]
Financing Receivable Modifications [Line Items]
Number Of Loans	1		0		1		0
Pre-Modification Recorded Investment	26,000		0		26,000		0
Post-Modification Recorded Investment	26,000		0		26,000		0
Financial Effect Of Modification On Recorded Investment	0	[1]	0	[1]	0	[1]	0	[1]
Financial Effect Of Modification On Interest	0	[2]	0	[2]	0	[2]	0	[2]
Consumer [Member] | Others [Member]
Financing Receivable Modifications [Line Items]
Number Of Loans	42	[3]	35	[3]	192	[3]	35	[3]
Pre-Modification Recorded Investment	320,000	[3]	300,000	[3]	1,717,000	[3]	300,000	[3]
Post-Modification Recorded Investment	320,000	[3]	300,000	[3]	1,717,000	[3]	300,000	[3]
Financial Effect Of Modification On Recorded Investment	0	[1],[3]	0	[1],[3]	0	[1],[3]	0	[1],[3]
Financial Effect Of Modification On Interest	0	[2],[3]	0	[2],[3]	0	[2],[3]	0	[2],[3]
Consumer [Member] | Subsequently Defaulted [Member]
Financing Receivable Modifications [Line Items]
Number Of Contracts Subsequently Defaulted	31		0		64		0
Recorded Investment Subsequently Defaulted	$ 263,000		$ 0		$ 468,000		$ 0

[1] Financial effects impacting the recorded investment include principal payments, advances, charge-offs, and capitalized past-due amounts.

[2] Represents the present value of interest rate concessions discounted at the effective rate of the original loan.

[3] Bankruptcies and maturity date extensions.