Loans And Allowance For Loan Losses (Summary Of Commercial Loans By Credit Quality) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	$ 4,235,429	$ 3,970,214
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	2,532,116	2,341,646
Commercial Real Estate - FL [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	84,642	154,081
Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	1,493,378	1,363,692
Commercial Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	125,293	110,795
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	3,907,473	3,578,997
Pass [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	2,317,580	2,127,334
Pass [Member] | Commercial Real Estate - FL [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	44,065	70,802
Pass [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	1,422,591	1,275,230
Pass [Member] | Commercial Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	123,237	105,631
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	100,293	142,347
Special Mention [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	63,685	73,701
Special Mention [Member] | Commercial Real Estate - FL [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	12,811	16,002
Special Mention [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	23,495	49,282
Special Mention [Member] | Commercial Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	302	3,362
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	214,627	246,828
Substandard [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	143,750	139,578
Substandard [Member] | Commercial Real Estate - FL [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	25,377	67,277
Substandard [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	43,746	38,171
Substandard [Member] | Commercial Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	1,754	1,802
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	13,036	2,042
Doubtful [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	7,101	1,033
Doubtful [Member] | Commercial Real Estate - FL [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	2,389
Doubtful [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total commercial loans and leases	$ 3,546	$ 1,009