Loans (Summary of the Aging Status of the Recorded Investment in Loans by Portfolio Segment/Class) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Originated Portfolio [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	$ 24,087	$ 17,045	$ 14,359
Financing receivable, recorded investment 61 to 89 days past due	5,795	3,679	8,258
Financing receivable, recorded investment accruing loans past due 90 days or more	1,251	2,359	2,646
Financing receivable, recorded investment, Nonaccrual loans	66,251	71,298	79,153
Financing receivable recorded investment, Total past due	97,384	94,381	104,416
Financing receivable, recorded investment, current	3,713,605	3,680,759	3,265,863
Financing receivable, recorded investment, Total loans	3,810,989	3,775,140	3,370,279
Originated Portfolio [Member] | Commercial [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	7,948	3,999	3,655
Financing receivable, recorded investment 61 to 89 days past due	1,664	730	1,793
Financing receivable, recorded investment accruing loans past due 90 days or more	4	0	1,005
Financing receivable, recorded investment, Nonaccrual loans	12,186	14,601	11,443
Financing receivable recorded investment, Total past due	21,802	19,330	17,896
Financing receivable, recorded investment, current	913,144	877,280	755,905
Financing receivable, recorded investment, Total loans	934,946	896,610	773,801
Originated Portfolio [Member] | Real estate commercial [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	9,195	5,852	4,632
Financing receivable, recorded investment 61 to 89 days past due	2,541	2,089	4,436
Financing receivable, recorded investment accruing loans past due 90 days or more	177	87	75
Financing receivable, recorded investment, Nonaccrual loans	35,849	37,660	46,870
Financing receivable recorded investment, Total past due	47,762	45,688	56,013
Financing receivable, recorded investment, current	920,533	910,477	794,347
Financing receivable, recorded investment, Total loans	968,295	956,165	850,360
Originated Portfolio [Member] | Real estate construction [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	0	0	0
Financing receivable, recorded investment 61 to 89 days past due	0	0	0
Financing receivable, recorded investment accruing loans past due 90 days or more	0	0	0
Financing receivable, recorded investment, Nonaccrual loans	168	1,217	61
Financing receivable recorded investment, Total past due	168	1,217	61
Financing receivable, recorded investment, current	51,680	47,906	38,672
Financing receivable, recorded investment, Total loans	51,848	49,123	38,733
Originated Portfolio [Member] | Land development [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	927	0	0
Financing receivable, recorded investment 61 to 89 days past due	0	0	0
Financing receivable, recorded investment accruing loans past due 90 days or more	0	0	0
Financing receivable, recorded investment, Nonaccrual loans	4,105	4,184	3,748
Financing receivable recorded investment, Total past due	5,032	4,184	3,748
Financing receivable, recorded investment, current	16,981	21,874	27,700
Financing receivable, recorded investment, Total loans	22,013	26,058	31,448
Originated Portfolio [Member] | Real estate residential [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	2,605	3,161	2,039
Financing receivable, recorded investment 61 to 89 days past due	831	55	1,314
Financing receivable, recorded investment accruing loans past due 90 days or more	196	1,503	333
Financing receivable, recorded investment, Nonaccrual loans	10,407	10,164	12,687
Financing receivable recorded investment, Total past due	14,039	14,883	16,373
Financing receivable, recorded investment, current	845,132	854,987	826,461
Financing receivable, recorded investment, Total loans	859,171	869,870	842,834
Originated Portfolio [Member] | Consumer installment [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	2,038	2,415	2,519
Financing receivable, recorded investment 61 to 89 days past due	524	378	410
Financing receivable, recorded investment accruing loans past due 90 days or more	0	0	0
Financing receivable, recorded investment, Nonaccrual loans	699	739	1,278
Financing receivable recorded investment, Total past due	3,261	3,532	4,207
Financing receivable, recorded investment, current	535,255	540,546	473,681
Financing receivable, recorded investment, Total loans	538,516	544,078	477,888
Originated Portfolio [Member] | Home equity [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	1,374	1,618	1,514
Financing receivable, recorded investment 61 to 89 days past due	235	427	305
Financing receivable, recorded investment accruing loans past due 90 days or more	874	769	1,233
Financing receivable, recorded investment, Nonaccrual loans	2,837	2,733	3,066
Financing receivable recorded investment, Total past due	5,320	5,547	6,118
Financing receivable, recorded investment, current	430,880	427,689	349,097
Financing receivable, recorded investment, Total loans	436,200	433,236	355,215
Acquired Portfolio [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	1,263	625	200
Financing receivable, recorded investment 61 to 89 days past due	190	15	196
Financing receivable, recorded investment accruing loans past due 90 days or more	8,609	9,099	15,495
Financing receivable, recorded investment, Nonaccrual loans	0	0	0
Financing receivable recorded investment, Total past due	10,062	9,739	15,891
Financing receivable, recorded investment, current	364,210	382,856	456,928
Financing receivable, recorded investment, Total loans	374,272	392,595	472,819
Acquired Portfolio [Member] | Commercial [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	191	0	0
Financing receivable, recorded investment 61 to 89 days past due	0	0	150
Financing receivable, recorded investment accruing loans past due 90 days or more	2,504	2,834	7,147
Financing receivable, recorded investment, Nonaccrual loans	0	0	0
Financing receivable recorded investment, Total past due	2,695	2,834	7,297
Financing receivable, recorded investment, current	100,474	103,278	122,837
Financing receivable, recorded investment, Total loans	103,169	106,112	130,134
Acquired Portfolio [Member] | Real estate commercial [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	479	287	0
Financing receivable, recorded investment 61 to 89 days past due	157	15	0
Financing receivable, recorded investment accruing loans past due 90 days or more	3,341	3,139	3,474
Financing receivable, recorded investment, Nonaccrual loans	0	0	0
Financing receivable recorded investment, Total past due	3,977	3,441	3,474
Financing receivable, recorded investment, current	190,111	202,255	241,959
Financing receivable, recorded investment, Total loans	194,088	205,696	245,433
Acquired Portfolio [Member] | Real estate construction [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	0	0	0
Financing receivable, recorded investment 61 to 89 days past due	0	0	0
Financing receivable, recorded investment accruing loans past due 90 days or more	0	0	0
Financing receivable, recorded investment, Nonaccrual loans	0	0	0
Financing receivable recorded investment, Total past due	0	0	0
Financing receivable, recorded investment, current	13,519	13,566	18,173
Financing receivable, recorded investment, Total loans	13,519	13,566	18,173
Acquired Portfolio [Member] | Land development [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	0	0	0
Financing receivable, recorded investment 61 to 89 days past due	0	0	0
Financing receivable, recorded investment accruing loans past due 90 days or more	2,602	2,834	3,362
Financing receivable, recorded investment, Nonaccrual loans	0	0	0
Financing receivable recorded investment, Total past due	2,602	2,834	3,362
Financing receivable, recorded investment, current	8,025	8,656	9,441
Financing receivable, recorded investment, Total loans	10,627	11,490	12,803
Acquired Portfolio [Member] | Real estate residential [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	405	123	85
Financing receivable, recorded investment 61 to 89 days past due	0	0	0
Financing receivable, recorded investment accruing loans past due 90 days or more	0	122	1,008
Financing receivable, recorded investment, Nonaccrual loans	0	0	0
Financing receivable recorded investment, Total past due	405	245	1,093
Financing receivable, recorded investment, current	12,878	13,720	17,374
Financing receivable, recorded investment, Total loans	13,283	13,965	18,467
Acquired Portfolio [Member] | Consumer installment [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	34	10	17
Financing receivable, recorded investment 61 to 89 days past due	33	0	3
Financing receivable, recorded investment accruing loans past due 90 days or more	0	0	0
Financing receivable, recorded investment, Nonaccrual loans	0	0	0
Financing receivable recorded investment, Total past due	67	10	20
Financing receivable, recorded investment, current	1,633	1,948	2,714
Financing receivable, recorded investment, Total loans	1,700	1,958	2,734
Acquired Portfolio [Member] | Home equity [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment 31 to 60 days past due	154	205	98
Financing receivable, recorded investment 61 to 89 days past due	0	0	43
Financing receivable, recorded investment accruing loans past due 90 days or more	162	170	504
Financing receivable, recorded investment, Nonaccrual loans	0	0	0
Financing receivable recorded investment, Total past due	316	375	645
Financing receivable, recorded investment, current	37,570	39,433	44,430
Financing receivable, recorded investment, Total loans	$ 37,886	$ 39,808	$ 45,075