Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
OPERATIONS:
Net interest income (loss)	$ 118,923	$ 117,443	$ 237,710	$ 239,269
Provision for loan losses	12,196	17,619	26,257	39,968
Other income	55,301	51,491	107,027	104,247
Other expenses	119,077	110,068	232,845	224,514
Net income (loss)	30,585	29,763	60,929	57,324
SegmentReportingInformationAverageAssets1	14,558,514	14,481,208	14,527,512	14,375,452
Commercial [Member]
OPERATIONS:
Net interest income (loss)	64,476	64,587	128,329	132,162
Provision for loan losses	3,465	15,090	12,570	25,107
Other income	18,047	12,620	32,356	27,413
Other expenses	40,128	35,732	83,479	73,346
Net income (loss)	25,304	17,150	42,013	39,729
SegmentReportingInformationAverageAssets1	6,364,148	6,133,210	6,346,311	6,114,006
Retail [Member]
OPERATIONS:
Net interest income (loss)	53,287	56,272	107,564	112,043
Provision for loan losses	1,728	6,517	4,265	12,466
Other income	24,177	25,785	49,443	49,976
Other expenses	56,784	58,539	115,830	119,370
Net income (loss)	12,319	11,050	23,992	19,619
SegmentReportingInformationAverageAssets1	2,918,710	2,934,633	2,914,532	2,944,264
Wealth [Member]
OPERATIONS:
Net interest income (loss)	4,590	4,707	9,189	9,531
Provision for loan losses	(24)	707	201	1,326
Other income	8,392	8,089	16,460	16,282
Other expenses	9,792	10,140	20,007	20,437
Net income (loss)	2,090	1,267	3,536	2,632
SegmentReportingInformationAverageAssets1	237,548	241,929	237,060	242,586
Other [Member]
OPERATIONS:
Net interest income (loss)	(3,430)	(8,123)	(7,372)	(14,467)
Provision for loan losses	7,027	(4,695)	9,221	1,069
Other income	4,685	4,997	8,768	10,576
Other expenses	12,373	5,657	13,529	11,361
Net income (loss)	(9,128)	296	(8,612)	(4,656)
SegmentReportingInformationAverageAssets1	$ 5,038,108	$ 5,171,436	$ 5,029,609	$ 5,074,596