Allowance for Loan Losses, Allowance for Losses on Lending-Related Commitments and Impaired Loans Allowance for Loan Losses, Allowance for Losses on Lending-Related Commitments and Impaired Loans (Summary Of Performing NonPerforming) (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013		Mar. 31, 2013
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	$ 13,133,160		$ 12,896,602		$ 11,900,312
Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	13,043,036		12,793,268		11,771,679
Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	90,124		103,334		128,633
Commercial
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	3,439,197		3,253,687		2,872,695
Commercial | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	3,427,028		3,242,907		2,854,322
Commercial | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	12,169		10,780		18,373
Commercial | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,995,309		1,836,206		1,569,576
Commercial | Commercial and industrial | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,983,810		1,826,063		1,551,859
Commercial | Commercial and industrial | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	11,499		10,143		17,717
Commercial | Franchise
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	221,101		220,383		194,511
Commercial | Franchise | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	221,101		220,383		194,386
Commercial | Franchise | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans					125
Commercial | Mortgage warehouse line of credit
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	60,809		67,470		131,970
Commercial | Mortgage warehouse line of credit | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	60,809		67,470		131,970
Commercial | Mortgage warehouse line of credit | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0		0		0
Commercial | Community Advantage - homeowners association
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	91,414		90,894		82,763
Commercial | Community Advantage - homeowners association | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	91,414		90,894		82,763
Commercial | Community Advantage - homeowners association | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0		0		0
Commercial | Aircraft
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	8,840		10,241		14,112
Commercial | Aircraft | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	8,840		10,241		14,112
Commercial | Aircraft | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0		0		0
Commercial | Asset-based lending
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	740,668		735,093		687,255
Commercial | Asset-based lending | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	739,998		734,456		686,724
Commercial | Asset-based lending | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	670		637		531
Commercial | Tax exempt
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	177,973		161,239		89,508
Commercial | Tax exempt | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	177,973		161,239		89,508
Commercial | Tax exempt | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0		0		0
Commercial | Leases
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	121,986		109,831		98,030
Commercial | Leases | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	121,986		109,831		98,030
Commercial | Leases | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0		0		0
Commercial | Other
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	10,261		11,147		127
Commercial | Other | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	10,261		11,147		127
Commercial | Other | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0		0		0
Commercial | PCI - commercial
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	10,836	[1],[2]	11,183	[1],[2]	4,843	[1],[2]
Commercial | PCI - commercial | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	10,836	[1]	11,183	[1]	4,843	[1]
Commercial | PCI - commercial | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0	[1]	0	[1]	0	[1]
Commercial real-estate
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	4,262,255		4,230,035		3,990,465
Commercial real-estate | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	4,228,522		4,183,147		3,928,658
Commercial real-estate | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	33,733		46,888		61,807
Commercial real-estate | Residential construction
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	36,397		38,500		37,083
Commercial real-estate | Residential construction | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	36,397		38,351		33,989
Commercial real-estate | Residential construction | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans			149		3,094
Commercial real-estate | Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	151,630		136,706		162,358
Commercial real-estate | Commercial construction | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	150,786		129,737		161,272
Commercial real-estate | Commercial construction | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	844		6,969		1,086
Commercial real-estate | Land
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	107,970		106,785		133,578
Commercial real-estate | Land | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	105,565		103,971		115,602
Commercial real-estate | Land | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	2,405		2,814		17,976
Commercial real-estate | Office
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	651,165		642,241		584,684
Commercial real-estate | Office | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	644,195		632,154		581,120
Commercial real-estate | Office | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	6,970		10,087		3,564
Commercial real-estate | Industrial
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	625,060		633,938		595,525
Commercial real-estate | Industrial | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	618,959		628,284		588,388
Commercial real-estate | Industrial | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	6,101		5,654		7,137
Commercial real-estate | Retail
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	677,430		656,259		586,801
Commercial real-estate | Retail | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	667,890		645,397		578,886
Commercial real-estate | Retail | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	9,540		10,862		7,915
Commercial real-estate | Multi-family
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	575,763		566,537		512,785
Commercial real-estate | Multi-family | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	574,436		564,502		510,697
Commercial real-estate | Multi-family | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,327		2,035		2,088
Commercial real-estate | Mixed use and other
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,361,236		1,372,454		1,322,834
Commercial real-estate | Mixed use and other | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,354,690		1,364,136		1,303,887
Commercial real-estate | Mixed use and other | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	6,546		8,318		18,947
Commercial real-estate | PCI - commercial real-estate
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	75,604	[1],[2]	76,615	[1]	54,817	[1],[2]
Commercial real-estate | PCI - commercial real-estate | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	75,604	[1]	76,615	[1]	54,817	[1]
Commercial real-estate | PCI - commercial real-estate | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0	[1]	0	[1]	0	[1]
Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	707,748		719,137		759,218
Home equity | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	700,437		709,066		744,327
Home equity | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	7,311		10,071		14,891
Residential real-estate
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	426,769		434,992		360,652
Residential real-estate | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	423,694		432,125		359,819
Residential real-estate | Residential real estate | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	409,309		417,151		350,213
Residential real-estate | Residential real estate | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	14,385		14,974		9,606
Residential real-estate | PCI - residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	3,075	[1],[2]	2,867	[1],[2]	833	[1],[2]
Residential real-estate | PCI - residential real estate | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	3,075	[1]	2,867	[1]	833	[1]
Residential real-estate | PCI - residential real estate | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0	[1]	0	[1]	0	[1]
Premium finance receivables | Commercial insurance loans
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	2,208,361		2,167,565		1,997,160
Premium finance receivables | Commercial insurance loans | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	2,187,036		2,148,186		1,977,415
Premium finance receivables | Commercial insurance loans | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	21,325		19,379		19,745
Premium finance receivables | Life insurance loans
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,516,132		1,499,792		1,253,781
Premium finance receivables | Life insurance loans | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,516,132		1,499,792		1,251,505
Premium finance receivables | Life insurance loans | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans					2,276
Premium finance receivables | PCI - life insurance loans
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	413,202	[1],[2]	423,906	[1],[2]	499,731	[1],[2]
Premium finance receivables | PCI - life insurance loans | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	413,202	[1]	423,906	[1]	499,731	[1]
Premium finance receivables | PCI - life insurance loans | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0	[1]	0	[1]	0	[1]
Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	159,496		167,488		166,610
Consumer and other | Consumer and other
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	159,254		166,284		163,972
Consumer and other | Consumer and other | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	158,053		165,042		162,037
Consumer and other | Consumer and other | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,201		1,242		1,935
Consumer and other | PCI - consumer and other
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	242	[1]	1,204	[1]	2,638	[1],[2]
Consumer and other | PCI - consumer and other | Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	242	[1]	1,204	[1]	2,638	[1]
Consumer and other | PCI - consumer and other | Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	$ 0	[1]	$ 0	[1]	$ 0	[1]

[1] PCI loans represent loans acquired with evidence of credit quality deterioration since origination, in accordance with ASC 310-30. See Note 6 - Loans for further discussion of these purchased loans.

[2] PCI loans represent loans acquired with evidence of credit quality deterioration since origination, in accordance with ASC 310-30. Loan agings are based upon contractually required payments.