Loans and Allowance for Loan Losses (Impairment Allowances) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Construction and Land Development Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	$ 6,215	$ 12,869	$ 6,903
Loans without a specific valuation allowance, Unpaid Principal Balance	8,569	17,072	9,257
Loans with a specific valuation allowance, Recorded Balance	3,900	4,632	3,435
Loans with a specific valuation allowance, Unpaid Principal Balance	3,900	7,307	3,435
Total, Recorded Balance	10,115	17,501	10,338
Total, Unpaid Principal Balance	12,469	24,379	12,692
Specific Allowance	2,217	1,689	2,036
Loans without a specific valuation allowance, Average Investment in Impaired Loans	6,343	13,900
Loans without a specific valuation allowance, Interest Income Recognized	68	150
Loans with a specific valuation allowance, Average Investment In Impaired Loans	3,893	4,634
Loans with a specific valuation allowance, Interest Income Recognized	41	32
Total, Average Investment In Impaired Loans	10,236	18,534
Total, Interest Income Recognized	109	182
Other Commercial Real Estate Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	19,213	33,625	27,156
Loans without a specific valuation allowance, Unpaid Principal Balance	19,656	36,738	27,353
Loans with a specific valuation allowance, Recorded Balance	12,502	9,109	14,766
Loans with a specific valuation allowance, Unpaid Principal Balance	13,913	10,137	16,177
Total, Recorded Balance	31,715	42,734	41,922
Total, Unpaid Principal Balance	33,569	46,875	43,530
Specific Allowance	2,351	1,340	2,421
Loans without a specific valuation allowance, Average Investment in Impaired Loans	24,018	34,382
Loans without a specific valuation allowance, Interest Income Recognized	257	408
Loans with a specific valuation allowance, Average Investment In Impaired Loans	12,346	9,614
Loans with a specific valuation allowance, Interest Income Recognized	147	61
Total, Average Investment In Impaired Loans	36,364	43,996
Total, Interest Income Recognized	404	469
Asset-based Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	0	0	0
Loans without a specific valuation allowance, Unpaid Principal Balance	0	0	0
Loans with a specific valuation allowance, Recorded Balance	0	0	0
Loans with a specific valuation allowance, Unpaid Principal Balance	0	0	0
Total, Recorded Balance	0	0	0
Total, Unpaid Principal Balance	0	0	0
Specific Allowance	0	0	0
Loans without a specific valuation allowance, Average Investment in Impaired Loans	0	0
Loans without a specific valuation allowance, Interest Income Recognized	0	0
Loans with a specific valuation allowance, Average Investment In Impaired Loans	0	0
Loans with a specific valuation allowance, Interest Income Recognized	0	0
Total, Average Investment In Impaired Loans	0	0
Total, Interest Income Recognized	0	0
Other Commercial Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	744	579	1,093
Loans without a specific valuation allowance, Unpaid Principal Balance	744	606	1,254
Loans with a specific valuation allowance, Recorded Balance	447	814	259
Loans with a specific valuation allowance, Unpaid Principal Balance	447	814	259
Total, Recorded Balance	1,191	1,393	1,352
Total, Unpaid Principal Balance	1,191	1,420	1,513
Specific Allowance	299	361	209
Loans without a specific valuation allowance, Average Investment in Impaired Loans	942	673
Loans without a specific valuation allowance, Interest Income Recognized	12	9
Loans with a specific valuation allowance, Average Investment In Impaired Loans	331	822
Loans with a specific valuation allowance, Interest Income Recognized	4	6
Total, Average Investment In Impaired Loans	1,273	1,495
Total, Interest Income Recognized	16	15
Home Equity Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	1,045	322	1,084
Loans without a specific valuation allowance, Unpaid Principal Balance	1,045	322	1,084
Loans with a specific valuation allowance, Recorded Balance	0	325	72
Loans with a specific valuation allowance, Unpaid Principal Balance	0	325	72
Total, Recorded Balance	1,045	647	1,156
Total, Unpaid Principal Balance	1,045	647	1,156
Specific Allowance	0	286	36
Loans without a specific valuation allowance, Average Investment in Impaired Loans	1,102	325
Loans without a specific valuation allowance, Interest Income Recognized	13	1
Loans with a specific valuation allowance, Average Investment In Impaired Loans	0	327
Loans with a specific valuation allowance, Interest Income Recognized	0	2
Total, Average Investment In Impaired Loans	1,102	652
Total, Interest Income Recognized	13	3
Other 1-4 Family Residential Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	5,596	4,455	6,577
Loans without a specific valuation allowance, Unpaid Principal Balance	5,673	4,527	6,687
Loans with a specific valuation allowance, Recorded Balance	1,730	2,353	1,920
Loans with a specific valuation allowance, Unpaid Principal Balance	1,730	2,353	1,920
Total, Recorded Balance	7,326	6,808	8,497
Total, Unpaid Principal Balance	7,403	6,880	8,607
Specific Allowance	359	420	496
Loans without a specific valuation allowance, Average Investment in Impaired Loans	6,226	5,280
Loans without a specific valuation allowance, Interest Income Recognized	57	53
Loans with a specific valuation allowance, Average Investment In Impaired Loans	1,689	2,356
Loans with a specific valuation allowance, Interest Income Recognized	16	31
Total, Average Investment In Impaired Loans	7,915	7,636
Total, Interest Income Recognized	73	84
Consumer Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	150	119	94
Loans without a specific valuation allowance, Unpaid Principal Balance	153	130	97
Loans with a specific valuation allowance, Recorded Balance	52	39	40
Loans with a specific valuation allowance, Unpaid Principal Balance	52	39	40
Total, Recorded Balance	202	158	134
Total, Unpaid Principal Balance	205	169	137
Specific Allowance	52	39	40
Loans without a specific valuation allowance, Average Investment in Impaired Loans	124	130
Loans without a specific valuation allowance, Interest Income Recognized	0	2
Loans with a specific valuation allowance, Average Investment In Impaired Loans	42	47
Loans with a specific valuation allowance, Interest Income Recognized	1	1
Total, Average Investment In Impaired Loans	166	177
Total, Interest Income Recognized	$ 1	$ 3