Impaired Loans and Valuation Allowance for Loan Losses (Details 3) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Average Recorded Investment
Average Recorded Investment, Total	$ 100,304	$ 134,196
Interest Income Recognized, Total	1,709	1,688
Construction and land development [Member]
Average Recorded Investment
Average Recorded Investment, With No Related Allowance	1,569	3,191
Average Recorded Investment, With Related Allowance	3,750	23,748
Average Recorded Investment, Total	5,319	26,939
Interest Income Recognized, With No Related Allowance	2	7
Interest Income Recognized, With Related Allowance	64	76
Interest Income Recognized, Total	66	83
Commercial real estate [Member]
Average Recorded Investment
Average Recorded Investment, With No Related Allowance	12,167	23,702
Average Recorded Investment, With Related Allowance	43,870	44,345
Average Recorded Investment, Total	56,037	68,047
Interest Income Recognized, With No Related Allowance	155	214
Interest Income Recognized, With Related Allowance	902	915
Interest Income Recognized, Total	1,057	1,129
Residential real estate [Member]
Average Recorded Investment
Average Recorded Investment, With No Related Allowance	10,145	8,912
Average Recorded Investment, With Related Allowance	27,648	27,408
Average Recorded Investment, Total	37,793	36,320
Interest Income Recognized, With No Related Allowance	137	22
Interest Income Recognized, With Related Allowance	429	436
Interest Income Recognized, Total	566	458
Commercial and financial [Member]
Average Recorded Investment
Average Recorded Investment, With No Related Allowance	11	1,536
Average Recorded Investment, With Related Allowance	39	203
Average Recorded Investment, Total	50	1,739
Interest Income Recognized, With No Related Allowance	0	0
Interest Income Recognized, With Related Allowance	8	2
Interest Income Recognized, Total	8	2
Consumer [Member]
Average Recorded Investment
Average Recorded Investment, With No Related Allowance	486	342
Average Recorded Investment, With Related Allowance	619	809
Average Recorded Investment, Total	1,105	1,151
Interest Income Recognized, With No Related Allowance	1	1
Interest Income Recognized, With Related Allowance	11	15
Interest Income Recognized, Total	$ 12	$ 16