Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
OPERATIONS:
Net interest income (loss)	$ 117,890	$ 119,392	$ 355,600	$ 358,659
Provision for loan losses	16,179	19,372	42,436	59,340
Other income	54,925	60,772	161,952	165,019
Other expenses	108,587	115,957	341,432	340,470
Net income (loss)	34,953	31,737	95,882	89,060
SegmentReportingInformationAverageAssets1	14,734,016	14,610,628	14,596,526	14,451,550
Commercial [Member]
OPERATIONS:
Net interest income (loss)	65,446	65,998	193,776	198,197
Provision for loan losses	10,401	4,546	22,970	29,653
Other income	15,247	16,219	47,603	43,632
Other expenses	39,595	36,745	123,074	110,073
Net income (loss)	19,954	40,644	61,967	100,519
SegmentReportingInformationAverageAssets1	6,466,355	6,258,625	6,386,617	6,162,742
Retail [Member]
OPERATIONS:
Net interest income (loss)	51,181	56,705	158,745	168,718
Provision for loan losses	1,194	5,249	5,459	17,715
Other income	26,783	28,333	76,226	78,309
Other expenses	53,788	57,567	169,618	177,201
Net income (loss)	14,939	20,464	38,931	45,779
SegmentReportingInformationAverageAssets1	2,960,336	2,925,345	2,929,911	2,937,888
Wealth [Member]
OPERATIONS:
Net interest income (loss)	4,223	4,568	13,412	14,205
Provision for loan losses	(519)	1,261	(318)	2,587
Other income	8,528	7,784	24,987	24,066
Other expenses	9,711	10,004	29,718	30,363
Net income (loss)	2,313	1,199	5,849	5,420
SegmentReportingInformationAverageAssets1	242,539	237,638	238,899	240,919
Other [Member]
OPERATIONS:
Net interest income (loss)	(2,960)	(7,879)	(10,333)	(22,461)
Provision for loan losses	5,103	8,316	14,325	9,385
Other income	4,367	8,436	13,136	19,012
Other expenses	5,493	11,641	19,022	22,833
Net income (loss)	(2,253)	(30,570)	(10,865)	(62,658)
SegmentReportingInformationAverageAssets1	$ 5,064,786	$ 5,189,020	$ 5,041,099	$ 5,110,001