Loans and leases and the allowance for credit losses (Details 5) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Interest income recognized on loans
Average Recorded Investment	$ 1,111,622	$ 1,161,292
Interest Income Recognized, Total	5,580	6,603
Interest Income Recognized, Cash Basis	2,759	3,229
Commercial, financial, leasing, etc. [Member]
Interest income recognized on loans
Average Recorded Investment	167,724	170,337
Interest Income Recognized, Total	409	993
Interest Income Recognized, Cash Basis	409	988
Commercial real estate loans [Member]
Interest income recognized on loans
Average Recorded Investment	178,315	189,779
Interest Income Recognized, Total	318	382
Interest Income Recognized, Cash Basis	318	339
Residential builder and developer [Member]
Interest income recognized on loans
Average Recorded Investment	282,495	326,815
Interest Income Recognized, Total	341	525
Interest Income Recognized, Cash Basis	179	128
Other commercial construction [Member]
Interest income recognized on loans
Average Recorded Investment	104,105	111,232
Interest Income Recognized, Total	170	510
Interest Income Recognized, Cash Basis	170	321
Residential real estate excluding Alt-A [Member]
Interest income recognized on loans
Average Recorded Investment	126,376	83,527
Interest Income Recognized, Total	1,342	997
Interest Income Recognized, Cash Basis	878	575
Residential Alt-A [Member]
Interest income recognized on loans
Average Recorded Investment	181,018	205,632
Interest Income Recognized, Total	1,843	1,995
Interest Income Recognized, Cash Basis	546	551
Home equity lines and loans [Member]
Interest income recognized on loans
Average Recorded Investment	9,998	12,076
Interest Income Recognized, Total	166	160
Interest Income Recognized, Cash Basis	42	25
Automobile [Member]
Interest income recognized on loans
Average Recorded Investment	53,289	58,863
Interest Income Recognized, Total	898	984
Interest Income Recognized, Cash Basis	178	296
Other [Member]
Interest income recognized on loans
Average Recorded Investment	8,302	3,031
Interest Income Recognized, Total	93	57
Interest Income Recognized, Cash Basis	$ 39	$ 6