Allowance For Loan Losses, Allowance For Losses On Lending-Related Commitments And Impaired Loans (Summary Of Activity In The Allowance For Credit Losses By Loan Portfolio) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses at beginning of period	$ 110,381	$ 113,903
Other adjustments	(238)
Reclassification to/from allowance for unfunded lending-related commitments	152	2,116
Charge-offs	(15,467)	(26,347)
Recoveries	1,041	1,001
Provision for credit losses	15,154	24,376
Allowance for loan losses at period end	111,023	115,049
Allowance for credit losses at period end	124,101	117,067
Allowance for unfunded lending-related commitments at period end	13,078	2,018
Allowance for credit losses, Individually evaluated for impairment	33,467	27,121
Allowance for credit losses, Collectively evaluated for impairment	90,634	89,946
Loans acquired with deteriorated credit quality
Loans, Individually evaluated for impairment	251,963	203,536
Loans, Collectively evaluated for impairment	9,845,919	8,683,190
Loans, Loans acquired with deteriorated credit quality	619,502	675,076
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses at beginning of period	31,237	31,777
Other adjustments	(3)
Reclassification to/from allowance for unfunded lending-related commitments	45
Charge-offs	(3,262)	(9,140)
Recoveries	257	266
Provision for credit losses	4,945	5,203
Allowance for loan losses at period end	33,219	28,106
Allowance for credit losses at period end	33,219	28,106
Allowance for credit losses, Individually evaluated for impairment	3,705	5,280
Allowance for credit losses, Collectively evaluated for impairment	29,514	22,826
Loans acquired with deteriorated credit quality
Loans, Individually evaluated for impairment	29,158	38,777
Loans, Collectively evaluated for impairment	2,509,353	1,898,784
Loans, Loans acquired with deteriorated credit quality	5,945
Commercial Real-Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses at beginning of period	56,405	62,618
Other adjustments	(222)
Reclassification to/from allowance for unfunded lending-related commitments	107	2,116
Charge-offs	(8,229)	(13,342)
Recoveries	131	338
Provision for credit losses	5,760	14,390
Allowance for loan losses at period end	53,952	66,120
Allowance for credit losses at period end	67,030	68,138
Allowance for unfunded lending-related commitments at period end	13,078	2,018
Allowance for credit losses, Individually evaluated for impairment	25,336	20,123
Allowance for credit losses, Collectively evaluated for impairment	41,694	48,015
Loans acquired with deteriorated credit quality
Loans, Individually evaluated for impairment	197,221	149,203
Loans, Collectively evaluated for impairment	3,336,217	3,207,359
Loans, Loans acquired with deteriorated credit quality	52,322
Home Equity [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses at beginning of period	7,712	6,213
Other adjustments	1
Charge-offs	(2,590)	(773)
Recoveries	162	8
Provision for credit losses	2,635	1,018
Allowance for loan losses at period end	7,920	6,466
Allowance for credit losses at period end	7,920	6,466
Allowance for credit losses, Individually evaluated for impairment	3,056	1,446
Allowance for credit losses, Collectively evaluated for impairment	4,864	5,020
Loans acquired with deteriorated credit quality
Loans, Individually evaluated for impairment	14,495	11,184
Loans, Collectively evaluated for impairment	825,869	880,148
Residential Real-Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses at beginning of period	5,028	5,107
Other adjustments	(14)
Charge-offs	(175)	(1,275)
Recoveries	2	2
Provision for credit losses	710	1,884
Allowance for loan losses at period end	5,551	5,718
Allowance for credit losses at period end	5,551	5,718
Allowance for credit losses, Individually evaluated for impairment	1,362	258
Allowance for credit losses, Collectively evaluated for impairment	4,189	5,460
Loans acquired with deteriorated credit quality
Loans, Individually evaluated for impairment	10,791	4,114
Loans, Collectively evaluated for impairment	349,879	340,795
Loans, Loans acquired with deteriorated credit quality	657
Premium Finance Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses at beginning of period	7,214	6,319
Charge-offs	(850)	(1,537)
Recoveries	298	268
Provision for credit losses	1,446	1,640
Allowance for loan losses at period end	8,108	6,690
Allowance for credit losses at period end	8,108	6,690
Allowance for credit losses, Collectively evaluated for impairment	8,108	6,690
Loans acquired with deteriorated credit quality
Loans, Collectively evaluated for impairment	2,645,989	2,202,296
Loans, Loans acquired with deteriorated credit quality	560,404	675,076
Indirect Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses at beginning of period	645	526
Charge-offs	(51)	(120)
Recoveries	30	66
Provision for credit losses	19	85
Allowance for loan losses at period end	643	557
Allowance for credit losses at period end	643	557
Allowance for credit losses, Individually evaluated for impairment	7	11
Allowance for credit losses, Collectively evaluated for impairment	636	546
Loans acquired with deteriorated credit quality
Loans, Individually evaluated for impairment	77	111
Loans, Collectively evaluated for impairment	67,368	52,268
Consumer And Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses at beginning of period	2,140	1,343
Charge-offs	(310)	(160)
Recoveries	161	53
Provision for credit losses	(361)	156
Allowance for loan losses at period end	1,630	1,392
Allowance for credit losses at period end	1,630	1,392
Allowance for credit losses, Individually evaluated for impairment	1	3
Allowance for credit losses, Collectively evaluated for impairment	1,629	1,389
Loans acquired with deteriorated credit quality
Loans, Individually evaluated for impairment	221	147
Loans, Collectively evaluated for impairment	111,244	101,540
Loans, Loans acquired with deteriorated credit quality	$ 174