Allowance For Loan Losses, Allowance For Losses On Lending-Related Commitments And Impaired Loans (Summary Of Recorded Investment Based On Performance Of Loans By Class) (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012		Mar. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	$ 11,900,312		$ 11,828,943		$ 10,717,384
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	2,872,695		2,914,798		2,544,456
Commercial Portfolio Segment [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,569,576		1,628,203		1,506,019
Commercial Portfolio Segment [Member] | Franchise [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	194,511		196,395		169,277
Commercial Portfolio Segment [Member] | Warehouse Agreement Borrowings [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	131,970		215,076		136,438
Commercial Portfolio Segment [Member] | Community Advantage - Homeowners Association [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	82,763		81,496		75,786
Commercial Portfolio Segment [Member] | Aircraft [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	14,112		17,364		19,891
Commercial Portfolio Segment [Member] | Asset-Based Lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	687,255		572,438		474,811
Commercial Portfolio Segment [Member] | Municipal Receivables [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	89,508		91,824		76,885
Commercial Portfolio Segment [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	98,030		90,443		77,671
Commercial Portfolio Segment [Member] | Other Receivables [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	127		16,549		1,733
Commercial Portfolio Segment [Member] | Purchased Non-Covered Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	4,843	[1],[2]	5,010	[1],[2]	5,945	[1],[2]
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	3,990,465		3,864,118		3,585,760
Commercial Real Estate Portfolio Segment [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	37,083		40,401		56,111
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	162,358		170,955		164,719
Commercial Real Estate Portfolio Segment [Member] | Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	133,578		134,197		184,042
Commercial Real Estate Portfolio Segment [Member] | Office [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	584,684		569,711		560,708
Commercial Real Estate Portfolio Segment [Member] | Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	595,525		577,937		590,903
Commercial Real Estate Portfolio Segment [Member] | Retail Site [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	586,801		568,896		528,077
Commercial Real Estate Portfolio Segment [Member] | Multi Family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	512,785		396,691		324,938
Commercial Real Estate Portfolio Segment [Member] | Mixed Use And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,322,834		1,349,254		1,123,940
Commercial Real Estate Portfolio Segment [Member] | Purchased Non-Covered Commercial Real-Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	54,817	[1],[2]	56,076	[1],[2]	52,322	[1],[2]
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	759,218		788,474		840,364
Residential Real-Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	360,652		367,213		361,327
Residential Real-Estate [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	359,819		366,357		360,670
Residential Real-Estate [Member] | Purchased Non Covered Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	833	[1],[2]	856	[1],[2]	657	[1],[2]
Premium Finance Receivable [Member] | Commercial Insurance Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,997,160		1,987,856		1,512,630
Premium Finance Receivable [Member] | Life Insurance Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,253,781		1,210,707		1,133,359
Premium Finance Receivable [Member] | Purchased Life Insurance Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	499,731	[1],[2]	514,459	[1],[2]	560,404	[1],[2]
Indirect Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	69,245		77,333		67,445
Consumer And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	97,365		103,985		111,639
Consumer And Other [Member] | Consumer Other Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	94,727		101,153		111,465
Consumer And Other [Member] | Purchased Non Covered Consumer And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	2,638	[1],[2]	2,832	[1],[2]	174	[1],[2]
Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	11,771,679		11,710,860		10,603,763
Performing Financing Receivable [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	2,854,322		2,893,061		2,524,621
Performing Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,551,859		1,608,794		1,488,627
Performing Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Franchise [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	194,386		194,603		167,485
Performing Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Warehouse Agreement Borrowings [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	131,970		215,076		136,438
Performing Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Community Advantage - Homeowners Association [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	82,763		81,496		75,786
Performing Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Aircraft [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	14,112		17,364		19,631
Performing Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Asset-Based Lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	686,724		571,902		474,420
Performing Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Municipal Receivables [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	89,508		91,824		76,885
Performing Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	98,030		90,443		77,671
Performing Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Other Receivables [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	127		16,549		1,733
Performing Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Purchased Non-Covered Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	4,843	[2]	5,010	[2]	5,945	[2]
Performing Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	3,928,658		3,814,145		3,522,983
Performing Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	33,989		37,291		54,304
Performing Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	161,272		168,796		162,330
Performing Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	115,602		122,898		158,736
Performing Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Office [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	581,120		565,515		552,174
Performing Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	588,388		575,848		589,039
Performing Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Retail Site [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	578,886		561,104		520,681
Performing Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Multi Family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	510,697		394,105		321,230
Performing Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Mixed Use And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,303,887		1,332,512		1,112,167
Performing Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Purchased Non-Covered Commercial Real-Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	54,817	[2]	56,076	[2]	52,322	[2]
Performing Financing Receivable [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	744,327		774,951		827,483
Performing Financing Receivable [Member] | Residential Real-Estate [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	350,213		354,629		355,341
Performing Financing Receivable [Member] | Residential Real-Estate [Member] | Purchased Non Covered Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	833	[2]	856	[2]	657	[2]
Performing Financing Receivable [Member] | Premium Finance Receivable [Member] | Commercial Insurance Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,977,415		1,968,546		1,500,361
Performing Financing Receivable [Member] | Premium Finance Receivable [Member] | Life Insurance Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,251,505		1,210,682		1,133,359
Performing Financing Receivable [Member] | Premium Finance Receivable [Member] | Purchased Life Insurance Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	499,731	[2]	514,459	[2]	560,404	[2]
Performing Financing Receivable [Member] | Indirect Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	69,005		77,089		67,036
Performing Financing Receivable [Member] | Consumer And Other [Member] | Consumer Other Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	93,032		99,610		111,344
Performing Financing Receivable [Member] | Consumer And Other [Member] | Purchased Non Covered Consumer And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	2,638	[2]	2,832	[2]	174	[2]
Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	128,633		118,083		113,621
Nonperforming Financing Receivable [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	18,373		21,737		19,835
Nonperforming Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	17,717		19,409		17,392
Nonperforming Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Franchise [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	125		1,792		1,792
Nonperforming Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Warehouse Agreement Borrowings [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0		0		0
Nonperforming Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Community Advantage - Homeowners Association [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0		0		0
Nonperforming Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Aircraft [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0		0		260
Nonperforming Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Asset-Based Lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	531		536		391
Nonperforming Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Municipal Receivables [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0		0		0
Nonperforming Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0		0		0
Nonperforming Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Other Receivables [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0		0		0
Nonperforming Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Purchased Non-Covered Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0	[2]	0	[2]	0	[2]
Nonperforming Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	61,807		49,973		62,777
Nonperforming Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	3,094		3,110		1,807
Nonperforming Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,086		2,159		2,389
Nonperforming Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	17,976		11,299		25,306
Nonperforming Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Office [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	3,564		4,196		8,534
Nonperforming Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	7,137		2,089		1,864
Nonperforming Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Retail Site [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	7,915		7,792		7,396
Nonperforming Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Multi Family [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	2,088		2,586		3,708
Nonperforming Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Mixed Use And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	18,947		16,742		11,773
Nonperforming Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Purchased Non-Covered Commercial Real-Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0	[2]	0	[2]	0	[2]
Nonperforming Financing Receivable [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	14,891		13,523		12,881
Nonperforming Financing Receivable [Member] | Residential Real-Estate [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	9,606		11,728		5,329
Nonperforming Financing Receivable [Member] | Residential Real-Estate [Member] | Purchased Non Covered Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0	[2]	0	[2]	0	[2]
Nonperforming Financing Receivable [Member] | Premium Finance Receivable [Member] | Commercial Insurance Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	19,745		19,310		12,269
Nonperforming Financing Receivable [Member] | Premium Finance Receivable [Member] | Life Insurance Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	2,276		25
Nonperforming Financing Receivable [Member] | Premium Finance Receivable [Member] | Purchased Life Insurance Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	0	[2]	0	[2]	0	[2]
Nonperforming Financing Receivable [Member] | Indirect Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	240		244		409
Nonperforming Financing Receivable [Member] | Consumer And Other [Member] | Consumer Other Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	1,695		1,543		121
Nonperforming Financing Receivable [Member] | Consumer And Other [Member] | Purchased Non Covered Consumer And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of unearned income, excluding covered loans	$ 0	[2]	$ 0	[2]	$ 0	[2]

[1] Purchased 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.

[2] Purchased 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.