Loans And Allowance For Loan Losses (Age Analysis Of Past Due Loans, By Class) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	$ 58,341	$ 46,174
>90 Days Past Due and Still Accruing	41,772	18,131
Non- Accrual	69,986	94,335
Total Past Due	170,099	158,640
Current	7,809,351	6,698,027
Total Loans	7,979,450	6,856,667
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	17,757	13,868
>90 Days Past Due and Still Accruing	11,443	9,612
Non- Accrual	37,644	37,134
Total Past Due	66,844	60,614
Current	2,530,185	2,281,032
Total Loans	2,597,029	2,341,646
Commercial Real Estate - FL [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	13,974	39,122
Total Past Due	13,974	39,122
Current	57,913	114,959
Total Loans	71,887	154,081
Commercial And Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	2,852	2,164
>90 Days Past Due and Still Accruing	1,069	690
Non- Accrual	6,564	6,956
Total Past Due	10,485	9,810
Current	1,521,881	1,353,882
Total Loans	1,532,366	1,363,692
Commercial Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	1,032	1,102
>90 Days Past Due and Still Accruing	44	5
Non- Accrual	1,141	1,084
Total Past Due	2,217	2,191
Current	124,848	108,604
Total Loans	127,065	110,795
Total Commercial Loans And Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	21,641	17,134
>90 Days Past Due and Still Accruing	12,556	10,307
Non- Accrual	59,323	84,296
Total Past Due	93,520	111,737
Current	4,234,827	3,858,477
Total Loans	4,328,347	3,970,214
Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	9,932	8,228
>90 Days Past Due and Still Accruing	3,175	3,614
Non- Accrual	3,087	2,525
Total Past Due	16,194	14,367
Current	1,112,116	1,014,820
Total Loans	1,128,310	1,029,187
Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	20,235	14,492
>90 Days Past Due and Still Accruing	24,824	3,342
Non- Accrual	2,587	2,443
Total Past Due	47,646	20,277
Current	1,073,591	650,659
Total Loans	1,121,237	670,936
Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	4,495	5,031
>90 Days Past Due and Still Accruing	374	282
Non- Accrual	1,054	918
Total Past Due	5,923	6,231
Current	578,016	534,558
Total Loans	583,939	540,789
Consumer Lines Of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	2,027	1,253
>90 Days Past Due and Still Accruing	831	586
Non- Accrual	435	653
Total Past Due	3,293	2,492
Current	776,862	604,788
Total Loans	780,155	607,280
Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 Days Past Due	11	36
>90 Days Past Due and Still Accruing	12
Non- Accrual	3,500	3,500
Total Past Due	3,523	3,536
Current	33,939	34,725
Total Loans	$ 37,462	$ 38,261