Loans (Details 5) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	$ 136,942	$ 160,595	$ 137,418	$ 161,838
Interest income recognized related to loans with impaired status	904	738	1,771	1,648
Commercial [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	29,018	29,814	27,183	31,279
Interest income recognized related to loans with impaired status	279	216	453	541
Real estate commercial [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	59,903	71,050	61,333	72,464
Interest income recognized related to loans with impaired status	202	152	430	396
Real estate construction [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	435	196	249	216
Interest income recognized related to loans with impaired status		15		30
Land development [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	8,301	13,750	8,014	14,203
Interest income recognized related to loans with impaired status	73	107	145	196
Real estate residential [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	35,100	39,369	36,365	37,777
Interest income recognized related to loans with impaired status	350	248	743	485
Consumer installment [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	1,219	3,032	1,379	2,808
Interest income recognized related to loans with impaired status
Home equity [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	2,966	3,384	2,895	3,091
Interest income recognized related to loans with impaired status