Loans and leases and the allowance for credit losses (Details 4) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Interest income recognized on loans
Average Recorded Investment	$ 1,250,482	$ 1,244,970	$ 1,255,808	$ 1,266,178
Interest Income Recognized, Total	5,989	5,567	12,648	10,655
Interest Income Recognized, Cash Basis	2,739	2,546	6,008	4,989
Commercial, financial, leasing [Member]
Interest income recognized on loans
Average Recorded Investment	180,000	297,364	183,482	307,404
Interest Income Recognized, Total	767	775	1,774	1,230
Interest Income Recognized, Cash Basis	754	765	1,755	1,220
Commercial Real Estate Excluding Residential Builder and Developer and Other Construction [Member]
Interest income recognized on loans
Average Recorded Investment	233,931	237,121	227,019	251,607
Interest Income Recognized, Total	513	139	897	510
Interest Income Recognized, Cash Basis	483	121	825	492
Residential builder and developer [Member]
Interest income recognized on loans
Average Recorded Investment	358,421	307,857	360,429	309,642
Interest Income Recognized, Total	312	671	839	715
Interest Income Recognized, Cash Basis	110	406	240	450
Other commercial construction [Member]
Interest income recognized on loans
Average Recorded Investment	107,494	49,894	117,669	51,970
Interest Income Recognized, Total	142	17	652	401
Interest Income Recognized, Cash Basis	105	17	426	401
Residential real estate excluding Alt-A [Member]
Interest income recognized on loans
Average Recorded Investment	97,317	60,593	90,813	52,932
Interest Income Recognized, Total	1,035	681	2,069	1,213
Interest Income Recognized, Cash Basis	551	432	1,147	781
Residential Alt-A [Member]
Interest income recognized on loans
Average Recorded Investment	199,056	223,430	202,339	225,391
Interest Income Recognized, Total	1,991	2,144	3,986	4,327
Interest Income Recognized, Cash Basis	409	447	960	885
Home equity lines and loans [Member]
Interest income recognized on loans
Average Recorded Investment	12,069	11,993	12,098	12,268
Interest Income Recognized, Total	190	167	351	359
Interest Income Recognized, Cash Basis	24	25	50	63
Automobile [Member]
Interest income recognized on loans
Average Recorded Investment	58,650	53,497	58,655	51,732
Interest Income Recognized, Total	984	910	1,968	1,771
Interest Income Recognized, Cash Basis	293	318	589	666
Other [Member]
Interest income recognized on loans
Average Recorded Investment	3,544	3,221	3,304	3,232
Interest Income Recognized, Total	55	63	112	129
Interest Income Recognized, Cash Basis	$ 10	$ 15	$ 16	$ 31