Loans (Summary of Impaired Loans by Classes of Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	$ 45,679	$ 23,234	$ 24,661
Unpaid Principal Balance	46,801	23,648	25,119
Related Valuation Allowance	6,648	1,338	1,503
Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	96,517	111,433	98,636
Unpaid Principal Balance	123,588	141,622	119,970
Related Valuation Allowance	0	0	0
Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	142,196	134,667	123,297
Unpaid Principal Balance	170,389	165,270	145,089
Related Valuation Allowance	6,648	1,338	1,503
Commercial [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	19,784	966	1,253
Unpaid Principal Balance	20,059	1,040	1,396
Related Valuation Allowance	5,711	293	313
Commercial [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	28,742	38,094	40,344
Unpaid Principal Balance	35,072	44,557	45,259
Related Valuation Allowance	0	0	0
Commercial [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	48,526	39,060	41,597
Unpaid Principal Balance	55,131	45,597	46,655
Related Valuation Allowance	5,711	293	313
Real estate commercial [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	4,634	2,587	3,779
Unpaid Principal Balance	5,481	2,927	4,094
Related Valuation Allowance	711	710	862
Real estate commercial [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	52,651	60,616	45,550
Unpaid Principal Balance	72,381	82,693	59,037
Related Valuation Allowance	0	0	0
Real estate commercial [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	57,285	63,203	49,329
Unpaid Principal Balance	77,862	85,620	63,131
Related Valuation Allowance	711	710	862
Real estate construction [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	400	162	162
Unpaid Principal Balance	480	255	369
Related Valuation Allowance	0	0	0
Real estate construction [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	400	162	162
Unpaid Principal Balance	480	255	369
Related Valuation Allowance	0	0	0
Land development [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	1,354	1,928	3,244
Unpaid Principal Balance	2,285	3,484	5,969
Related Valuation Allowance	0	0	0
Land development [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	1,354	1,928	3,244
Unpaid Principal Balance	2,285	3,484	5,969
Related Valuation Allowance	0	0	0
Real estate residential [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	21,261	19,681	19,629
Unpaid Principal Balance	21,261	19,681	19,629
Related Valuation Allowance	226	335	328
Real estate residential [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	9,635	7,994	6,693
Unpaid Principal Balance	9,635	7,994	6,693
Related Valuation Allowance	0	0	0
Real estate residential [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	30,896	27,675	26,322
Unpaid Principal Balance	30,896	27,675	26,322
Related Valuation Allowance	226	335	328
Consumer installment [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	603	518	527
Unpaid Principal Balance	603	518	527
Related Valuation Allowance	0	0	0
Consumer installment [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	603	518	527
Unpaid Principal Balance	603	518	527
Related Valuation Allowance	0	0	0
Home equity [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	3,132	2,121	2,116
Unpaid Principal Balance	3,132	2,121	2,116
Related Valuation Allowance	0	0	0
Home equity [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	3,132	2,121	2,116
Unpaid Principal Balance	3,132	2,121	2,116
Related Valuation Allowance	$ 0	$ 0	$ 0