Loans and Allowance for Loan Losses (Impairment Allowances) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Construction and Land Development Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	$ 7,028	$ 13,493	$ 7,028	$ 13,493	$ 9,539
Loans without a specific valuation allowance, Unpaid Principal Balance	9,382	18,319	9,382	18,319	13,915
Loans with a specific valuation allowance, Recorded Balance	4,344	14,209	4,344	14,209	8,620
Loans with a specific valuation allowance, Unpaid Principal Balance	4,344	18,046	4,344	18,046	11,294
Total, Recorded Balance	11,372	27,702	11,372	27,702	18,159
Total, Unpaid Principal Balance	13,726	36,365	13,726	36,365	25,209
Specific Allowance	1,120	3,333	1,120	3,333	1,750
Loans without a specific valuation allowance, Average Investment in Impaired Loans	11,818	9,294	12,856	14,894
Loans without a specific valuation allowance, Interest Income Recognized	77	115	228	247
Loans with a specific valuation allowance, Average Investment In Impaired Loans	4,351	16,583	4,491	14,700
Loans with a specific valuation allowance, Interest Income Recognized	70	97	101	193
Total, Average Investment In Impaired Loans	16,169	25,877	17,347	29,594
Total, Interest Income Recognized	147	212	329	440
Other Commercial Real Estate Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	37,763	34,100	37,763	34,100	33,048
Loans without a specific valuation allowance, Unpaid Principal Balance	39,601	36,754	39,601	36,754	36,117
Loans with a specific valuation allowance, Recorded Balance	6,933	16,459	6,933	16,459	7,722
Loans with a specific valuation allowance, Unpaid Principal Balance	6,962	18,129	6,962	18,129	8,471
Total, Recorded Balance	44,696	50,559	44,696	50,559	40,770
Total, Unpaid Principal Balance	46,563	54,883	46,563	54,883	44,588
Specific Allowance	1,372	2,658	1,372	2,658	894
Loans without a specific valuation allowance, Average Investment in Impaired Loans	35,435	19,933	34,911	34,179
Loans without a specific valuation allowance, Interest Income Recognized	435	290	844	774
Loans with a specific valuation allowance, Average Investment In Impaired Loans	11,178	23,563	10,400	16,656
Loans with a specific valuation allowance, Interest Income Recognized	168	1	229	47
Total, Average Investment In Impaired Loans	46,613	43,496	45,311	50,835
Total, Interest Income Recognized	603	291	1,073	821
Asset-based Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	0	0	0	0	0
Loans without a specific valuation allowance, Unpaid Principal Balance	0	0	0	0	0
Loans with a specific valuation allowance, Recorded Balance	0	0	0	0	0
Loans with a specific valuation allowance, Unpaid Principal Balance	0	0	0	0	0
Total, Recorded Balance	0	0	0	0	0
Total, Unpaid Principal Balance	0	0	0	0	0
Specific Allowance	0	0	0	0	0
Loans without a specific valuation allowance, Average Investment in Impaired Loans	0	0	0	0
Loans without a specific valuation allowance, Interest Income Recognized	0	0	0	0
Loans with a specific valuation allowance, Average Investment In Impaired Loans	0	0	0	0
Loans with a specific valuation allowance, Interest Income Recognized	0	0	0	0
Total, Average Investment In Impaired Loans	0	0	0	0
Total, Interest Income Recognized	0	0	0	0
Other Commercial Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	687	728	687	728	433
Loans without a specific valuation allowance, Unpaid Principal Balance	713	754	713	754	460
Loans with a specific valuation allowance, Recorded Balance	684	3,393	684	3,393	1,111
Loans with a specific valuation allowance, Unpaid Principal Balance	813	3,545	813	3,545	1,111
Total, Recorded Balance	1,371	4,121	1,371	4,121	1,544
Total, Unpaid Principal Balance	1,526	4,299	1,526	4,299	1,571
Specific Allowance	496	1,341	496	1,341	485
Loans without a specific valuation allowance, Average Investment in Impaired Loans	664	0	669	3,156
Loans without a specific valuation allowance, Interest Income Recognized	13	0	22	79
Loans with a specific valuation allowance, Average Investment In Impaired Loans	576	5,490	698	3,413
Loans with a specific valuation allowance, Interest Income Recognized	1	53	7	62
Total, Average Investment In Impaired Loans	1,240	5,490	1,367	6,569
Total, Interest Income Recognized	14	53	29	141
Home Equity Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	1,099	721	1,099	721	159
Loans without a specific valuation allowance, Unpaid Principal Balance	1,099	721	1,099	721	159
Loans with a specific valuation allowance, Recorded Balance	74	0	74	0	456
Loans with a specific valuation allowance, Unpaid Principal Balance	74	0	74	0	456
Total, Recorded Balance	1,173	721	1,173	721	615
Total, Unpaid Principal Balance	1,173	721	1,173	721	615
Specific Allowance	36	0	36	0	166
Loans without a specific valuation allowance, Average Investment in Impaired Loans	1,135	730	732	719
Loans without a specific valuation allowance, Interest Income Recognized	13	4	14	4
Loans with a specific valuation allowance, Average Investment In Impaired Loans	76	0	201	0
Loans with a specific valuation allowance, Interest Income Recognized	4	0	6	0
Total, Average Investment In Impaired Loans	1,211	730	933	719
Total, Interest Income Recognized	17	4	20	4
Other 1-4 Family Residential Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	4,187	2,835	4,187	2,835	4,466
Loans without a specific valuation allowance, Unpaid Principal Balance	4,245	2,836	4,245	2,836	4,732
Loans with a specific valuation allowance, Recorded Balance	2,239	3,286	2,239	3,286	1,843
Loans with a specific valuation allowance, Unpaid Principal Balance	2,239	3,307	2,239	3,307	1,843
Total, Recorded Balance	6,426	6,121	6,426	6,121	6,309
Total, Unpaid Principal Balance	6,484	6,143	6,484	6,143	6,575
Specific Allowance	520	1,261	520	1,261	397
Loans without a specific valuation allowance, Average Investment in Impaired Loans	4,159	2,905	4,716	3,000
Loans without a specific valuation allowance, Interest Income Recognized	65	31	118	65
Loans with a specific valuation allowance, Average Investment In Impaired Loans	2,561	3,725	2,460	3,291
Loans with a specific valuation allowance, Interest Income Recognized	18	40	49	44
Total, Average Investment In Impaired Loans	6,720	6,630	7,176	6,291
Total, Interest Income Recognized	83	71	167	109
Consumer Loans
Financing Receivable, Impaired [Line Items]
Loans without a specific valuation allowance, Recorded Balance	112	452	112	452	128
Loans without a specific valuation allowance, Unpaid Principal Balance	124	462	124	462	154
Loans with a specific valuation allowance, Recorded Balance	94	54	94	54	37
Loans with a specific valuation allowance, Unpaid Principal Balance	95	54	95	54	37
Total, Recorded Balance	206	506	206	506	165
Total, Unpaid Principal Balance	219	516	219	516	191
Specific Allowance	94	40	94	40	37
Loans without a specific valuation allowance, Average Investment in Impaired Loans	108	416	119	471
Loans without a specific valuation allowance, Interest Income Recognized	3	7	5	14
Loans with a specific valuation allowance, Average Investment In Impaired Loans	126	7	87	56
Loans with a specific valuation allowance, Interest Income Recognized	2	1	3	1
Total, Average Investment In Impaired Loans	234	423	206	527
Total, Interest Income Recognized	$ 5	$ 8	$ 8	$ 15