Loans (Summary of Information Related to Impaired Loans) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	$ 127,956	$ 121,855	$ 128,707	$ 124,715
Interest income recognized related to loans with impaired status	1,075	1,005	2,109	1,874
Commercial [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	42,629	26,704	42,118	26,828
Interest income recognized related to loans with impaired status	347	225	680	418
Real estate commercial [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	51,260	53,434	52,290	55,090
Interest income recognized related to loans with impaired status	366	412	727	700
Real estate construction [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	163	410	165	386
Interest income recognized related to loans with impaired status	0	3	0	5
Land development [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	4,312	10,879	4,478	10,897
Interest income recognized related to loans with impaired status	34	91	71	182
Real estate residential [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	26,737	26,903	26,758	27,911
Interest income recognized related to loans with impaired status	328	274	631	569
Consumer installment [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	634	647	704	683
Interest income recognized related to loans with impaired status	0	0	0	0
Home equity [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	2,221	2,878	2,194	2,920
Interest income recognized related to loans with impaired status	$ 0	$ 0	$ 0	$ 0