Impaired Loans and Valuation Allowance for Loan Losses - Company's Recorded Investments in Impaired Loans and the Related Valuation Allowances (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Recorded Investment
Total	$ 43,577	$ 52,969
Unpaid Principal Balance
Total	51,269	62,446
Related Valuation Allowance
Total	3,541	5,446
Average Recorded Investment
Total	49,602	66,603	96,439
Interest Income Recognized
Total	1,345	1,260	3,054
Construction Land Development [Member]
Recorded Investment
Impaired Financing Receivable, with No Related Allowance, Recorded	1,824	2,561
Impaired Financing Receivable, with Related Allowance, Recorded	886	1,120
Total	2,710	3,681
Unpaid Principal Balance
Impaired Financing Receivable, with No Related Allowance Recorded	2,239	3,180
Impaired Financing Receivable, with Related Allowance Recorded	931	1,197
Total	3,170	4,377
Related Valuation Allowance
Impaired Financing Receivable With No Related Allowance Recorded	0	0
Impaired Financing Receivable With Related Allowance Recorded	159	149
Total	159	149
Average Recorded Investment
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	2,080	2,446
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,213	1,347
Total	3,293	3,793
Interest Income Recognized
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	106	102
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	81	36
Total	187	138
Commercial Real Estate [Member]
Recorded Investment
Impaired Financing Receivable, with No Related Allowance, Recorded	3,087	4,481
Impaired Financing Receivable, with Related Allowance, Recorded	8,359	7,937
Total	11,446	12,418
Unpaid Principal Balance
Impaired Financing Receivable, with No Related Allowance Recorded	4,600	6,577
Impaired Financing Receivable, with Related Allowance Recorded	8,469	8,046
Total	13,069	14,623
Related Valuation Allowance
Impaired Financing Receivable With No Related Allowance Recorded	0	0
Impaired Financing Receivable With Related Allowance Recorded	529	638
Total	529	638
Average Recorded Investment
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	2,713	7,382
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	10,446	17,264
Total	13,159	24,646
Interest Income Recognized
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	20	28
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	461	395
Total	481	423
Residential Real Estate [Member]
Recorded Investment
Impaired Financing Receivable, with No Related Allowance, Recorded	11,898	12,366
Impaired Financing Receivable, with Related Allowance, Recorded	16,804	23,365
Total	28,702	35,731
Unpaid Principal Balance
Impaired Financing Receivable, with No Related Allowance Recorded	16,562	17,372
Impaired Financing Receivable, with Related Allowance Recorded	17,693	24,766
Total	34,255	42,138
Related Valuation Allowance
Impaired Financing Receivable With No Related Allowance Recorded	0	0
Impaired Financing Receivable With Related Allowance Recorded	2,741	4,528
Total	2,741	4,528
Average Recorded Investment
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	11,366	14,512
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	20,793	22,899
Total	32,159	37,411
Interest Income Recognized
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	198	81
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	445	566
Total	643	647
Commercial And Financial [Member]
Recorded Investment
Impaired Financing Receivable, with No Related Allowance, Recorded	120	153
Impaired Financing Receivable, with Related Allowance, Recorded	0	13
Total	120	166
Unpaid Principal Balance
Impaired Financing Receivable, with No Related Allowance Recorded	120	153
Impaired Financing Receivable, with Related Allowance Recorded	0	13
Total	120	166
Related Valuation Allowance
Impaired Financing Receivable With No Related Allowance Recorded	0	0
Impaired Financing Receivable With Related Allowance Recorded	0	13
Total	0	13
Average Recorded Investment
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	110	19
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	47	1
Total	157	20
Interest Income Recognized
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	8	9
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	1
Total	8	10
Consumer [Member]
Recorded Investment
Impaired Financing Receivable, with No Related Allowance, Recorded	65	425
Impaired Financing Receivable, with Related Allowance, Recorded	534	548
Total	599	973
Unpaid Principal Balance
Impaired Financing Receivable, with No Related Allowance Recorded	93	569
Impaired Financing Receivable, with Related Allowance Recorded	562	573
Total	655	1,142
Related Valuation Allowance
Impaired Financing Receivable With No Related Allowance Recorded	0	0
Impaired Financing Receivable With Related Allowance Recorded	112	118
Total	112	118
Average Recorded Investment
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	291	162
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	543	571
Total	834	733
Interest Income Recognized
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	1	19
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	25	23
Total	$ 26	$ 42