Loans (Schedule Of Allowances For Loan Losses By Portfolio Segment) (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Balance balance	$ 35,156	$ 34,576	$ 34,576
Provision for loan losses	(24,360)	(22,098)	(30,341)
Loans charged off	(34,167)	(22,714)	(31,623)
Recoveries of loans previously charged off	552	1,278	1,862
Ending balance	25,901	35,238	35,156
Loans Receivable
Balance balance	35,156	34,576	34,576
Provision for loan losses	24,360	22,098	30,341
Loans charged off	(34,167)	(22,714)	(31,623)
Recoveries of loans previously charged off	552	1,278	1,862
Ending balance	25,901	35,238	35,156
Period-end amount allocated to:
Individually evaluated for impairment	5,556	14,025	15,966
Loans collectively evaluated for impairment	20,345	21,213	19,190
Ending balance	25,901	35,238	35,156
Loans:
Individually evaluated for impairment	44,988	64,570	77,573
Collectively evaluated for impairment	1,394,874	1,304,325	1,254,513
Ending balance	1,439,862	1,368,895	1,332,086
Commercial, financial & agricultural | Loans Receivable
Balance balance	2,918	2,779	2,779
Provision for loan losses	677	3,586	5,772
Loans charged off	(889)	(3,855)	(5,807)
Recoveries of loans previously charged off	101	153	174
Ending balance	2,807	2,663	2,918
Commercial, financial & agricultural | Period-end amount allocated to:
Individually evaluated for impairment	610	903	766
Loans collectively evaluated for impairment	2,197	1,760	2,152
Ending balance	2,807	2,663	2,918
Commercial, financial & agricultural | Loans:
Individually evaluated for impairment	2,748	3,214	2,831
Collectively evaluated for impairment	186,626	155,806	140,129
Ending balance	189,374	159,020	142,960
Real estate - construction & development | Loans Receivable
Balance balance	9,438	7,705	7,705
Provision for loan losses	4,954	7,615	11,354
Loans charged off	(7,819)	(6,859)	(10,988)
Recoveries of loans previously charged off	23	873	1,367
Ending balance	6,596	9,334	9,438
Real estate - construction & development | Period-end amount allocated to:
Individually evaluated for impairment	526	5,209	3,478
Loans collectively evaluated for impairment	6,070	4,125	5,960
Ending balance	6,596	9,334	9,438
Real estate - construction & development | Loans:
Individually evaluated for impairment	5,510	13,979	13,561
Collectively evaluated for impairment	119,805	131,791	116,709
Ending balance	125,315	145,770	130,270
Real estate - commercial and farmland | Loans Receivable
Balance balance	14,226	14,971	14,971
Provision for loan losses	13,087	6,447	7,883
Loans charged off	(18,199)	(7,851)	(8,680)
Recoveries of loans previously charged off	32	43	52
Ending balance	9,146	13,610	14,226
Real estate - commercial and farmland | Period-end amount allocated to:
Individually evaluated for impairment	2,315	4,580	8,152
Loans collectively evaluated for impairment	6,831	9,030	6,074
Ending balance	9,146	13,610	14,226
Real estate - commercial and farmland | Loans:
Individually evaluated for impairment	21,552	31,892	45,084
Collectively evaluated for impairment	691,688	645,156	627,681
Ending balance	713,240	677,048	672,765
Real estate - residential | Loans Receivable
Balance balance	8,128	8,664	8,664
Provision for loan losses	4,936	3,931	4,717
Loans charged off	(6,642)	(3,641)	(5,399)
Recoveries of loans previously charged off	199	107	146
Ending balance	6,621	9,061	8,128
Real estate - residential | Period-end amount allocated to:
Individually evaluated for impairment	2,105	3,332	3,567
Loans collectively evaluated for impairment	4,516	5,729	4,561
Ending balance	6,621	9,061	8,128
Real estate - residential | Loans:
Individually evaluated for impairment	15,178	15,468	16,080
Collectively evaluated for impairment	328,154	315,768	314,647
Ending balance	343,332	331,236	330,727
Consumer Installment and Other | Loans Receivable
Balance balance	446	457	457
Provision for loan losses	706	519	615
Loans charged off	(618)	(508)	(749)
Recoveries of loans previously charged off	197	102	123
Ending balance	731	570	446
Consumer Installment and Other | Period-end amount allocated to:
Individually evaluated for impairment		1	3
Loans collectively evaluated for impairment	731	569	443
Ending balance	731	570	446
Consumer Installment and Other | Loans:
Individually evaluated for impairment		17	17
Collectively evaluated for impairment	68,601	55,804	55,347
Ending balance	$ 68,601	$ 55,821	$ 55,364