Loans and leases and the allowance for credit losses (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
Interest income recognized on loans
Average Recorded Investment	$ 1,087,554	$ 1,130,660	$ 1,100,021	$ 1,146,942
Interest Income Recognized, Total	11,415	5,941	16,995	12,544
Interest Income Recognized, Cash Basis	8,693	2,714	11,452	5,943
Commercial, financial, leasing [Member]
Interest income recognized on loans
Average Recorded Investment	161,311	162,827	164,779	167,456
Interest Income Recognized, Total	743	679	1,152	1,672
Interest Income Recognized, Cash Basis	743	666	1,152	1,654
Commercial real estate loans [Member]
Interest income recognized on loans
Average Recorded Investment	180,199	194,508	179,213	191,472
Interest Income Recognized, Total	1,238	513	1,556	895
Interest Income Recognized, Cash Basis	1,238	483	1,556	822
Residential builder and developer [Member]
Interest income recognized on loans
Average Recorded Investment	262,254	308,709	271,903	317,054
Interest Income Recognized, Total	385	314	726	839
Interest Income Recognized, Cash Basis	252	112	431	240
Other commercial construction [Member]
Interest income recognized on loans
Average Recorded Investment	109,037	93,980	107,151	103,751
Interest Income Recognized, Total	4,840	187	5,010	697
Interest Income Recognized, Cash Basis	4,840	150	5,010	471
Residential real estate excluding Alt-A [Member]
Interest income recognized on loans
Average Recorded Investment	127,258	97,317	126,880	90,813
Interest Income Recognized, Total	1,315	1,029	2,657	2,026
Interest Income Recognized, Cash Basis	810	565	1,688	1,140
Residential Alt-A [Member]
Interest income recognized on loans
Average Recorded Investment	174,181	199,056	177,623	202,339
Interest Income Recognized, Total	1,753	1,991	3,596	3,986
Interest Income Recognized, Cash Basis	527	410	1,073	961
Home equity lines and loans [Member]
Interest income recognized on loans
Average Recorded Investment	11,237	12,069	10,593	12,098
Interest Income Recognized, Total	164	189	330	349
Interest Income Recognized, Cash Basis	46	23	88	48
Automobile [Member]
Interest income recognized on loans
Average Recorded Investment	52,200	58,650	52,799	58,655
Interest Income Recognized, Total	871	984	1,769	1,968
Interest Income Recognized, Cash Basis	190	292	368	588
Other [Member]
Interest income recognized on loans
Average Recorded Investment	9,877	3,544	9,080	3,304
Interest Income Recognized, Total	106	55	199	112
Interest Income Recognized, Cash Basis	$ 47	$ 13	$ 86	$ 19