Loans and Leases - Reserve for Loan and Lease Losses Roll Forward (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($) loan borrowers	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 20,934	$ 24,567	$ 20,662	$ 24,494
Charge-offs	(2,770)	(2,019)	(3,863)	(3,981)
Recoveries	297	295	588	855
Provision (recovery of provision)	1,141	1,251	2,215	2,726
Ending balance	19,602	24,094	19,602	24,094
Commercial, Financial and Agricultural [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	6,712	9,547	6,920	9,789
Charge-offs	(1,038)	(250)	(1,338)	(1,689)
Recoveries	115	63	225	109
Provision (recovery of provision)	1,058	354	1,040	1,505
Ending balance	6,847	9,714	6,847	9,714
Real Estate-Commercial and Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Amount of Loans Charged Off Prior to Being Transferred to Loans Held For Sale	$ 1,300		1,300
Number of Loans Charged Off Prior to Being Transferred to Loans Held for Sale | loan	2
Number of Borrowers, Loans Charged Off Prior to Being Transferred to Loans Held for Sale | borrowers	1
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 9,648	9,247	8,943	8,780
Charge-offs	(1,348)	(1,251)	(1,696)	(1,308)
Recoveries	91	0	156	370
Provision (recovery of provision)	(590)	1,267	398	1,421
Ending balance	7,801	9,263	7,801	9,263
Real Estate-Residential Secured for Business Purpose [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	668	1,056	763	1,062
Charge-offs	(24)	(98)	(24)	(114)
Recoveries	7	45	13	48
Provision (recovery of provision)	(35)	22	(136)	29
Ending balance	616	1,025	616	1,025
Real Estate-Residential and Home Equity Secured for Personal Purpose [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,128	1,221	1,124	1,284
Charge-offs	(107)	(10)	(138)	(90)
Recoveries	0	26	1	27
Provision (recovery of provision)	167	11	201	27
Ending balance	1,188	1,248	1,188	1,248
Loans to Individuals [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	365	598	360	694
Charge-offs	(64)	(267)	(248)	(490)
Recoveries	41	81	89	159
Provision (recovery of provision)	47	(7)	188	42
Ending balance	389	405	389	405
Lease Financings [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,013	1,295	985	1,285
Charge-offs	(189)	(143)	(419)	(290)
Recoveries	43	80	104	142
Provision (recovery of provision)	258	(131)	455	(36)
Ending balance	1,125	1,101	1,125	1,101
Unallocated Financing Receivables [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,400	1,603	1,567	1,600
Provision (recovery of provision)	236	(265)	69	(262)
Ending balance	$ 1,636	$ 1,338	$ 1,636	$ 1,338