Estimated Fair Value Of Financial Instruments (Financial Instruments) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Estimated Fair Value Of Financial Instruments [Line Items]
Cash and due from banks	$ 141,563		$ 156,131
Federal funds sold and other short-term investments	315,378		205,610
Loans held for sale	35,342		32,049
Securities available-for-sale	1,625,649		1,783,465
Securities held-to-maturity	693,277		490,143
Securities held-to-maturity	706,748		493,230
Non-marketable equity investments	47,702		43,604
Loans, net of allowance for loan losses and unearned fees	9,261,933		8,816,967
Covered assets, net of allowance for covered loan losses	223,049		280,868
Accrued interest receivable	37,089		35,732
Investment in BOLI	51,751		50,966
Capital markets derivative assets	102,613	[1]	101,676	[1]
Deposits	10,734,530		10,392,854
Short-term borrowings	335,000		156,000
Long-term debt	374,793		379,793
Accrued interest payable	5,855		5,567
Capital markets derivative liabilities	105,773	[1]	104,140	[1]
Estimate of Fair Value, Fair Value Disclosure [Member]
Estimated Fair Value Of Financial Instruments [Line Items]
Cash and due from banks	141,563		156,131
Federal funds sold and other short-term investments	315,378		205,610
Loans held for sale	35,342		32,049
Securities available-for-sale	1,625,649		1,783,465
Securities held-to-maturity	706,748		493,230
Non-marketable equity investments	47,702		43,604
Loans, net of allowance for loan losses and unearned fees	9,119,121		8,465,358
Covered assets, net of allowance for covered loan losses	243,600		306,976
Accrued interest receivable	37,089		35,732
Investment in BOLI	51,751		50,966
Capital markets derivative assets	102,613		101,676
Deposits	10,745,791		10,405,158
Short-term borrowings	335,212		156,047
Long-term debt	353,783		343,121
Accrued interest payable	5,855		5,567
Capital markets derivative liabilities	105,773		104,140
Fair Value, Inputs, Level 1 [Member]
Estimated Fair Value Of Financial Instruments [Line Items]
Cash and due from banks	141,563		156,131
Federal funds sold and other short-term investments
Loans held for sale
Securities available-for-sale	88,252		61,521
Securities held-to-maturity
Non-marketable equity investments
Loans, net of allowance for loan losses and unearned fees
Covered assets, net of allowance for covered loan losses
Accrued interest receivable
Investment in BOLI
Capital markets derivative assets
Deposits
Short-term borrowings
Long-term debt	150,660
Accrued interest payable
Capital markets derivative liabilities
Fair Value, Inputs, Level 2 [Member]
Estimated Fair Value Of Financial Instruments [Line Items]
Cash and due from banks
Federal funds sold and other short-term investments	315,378		205,610
Loans held for sale	35,342		32,049
Securities available-for-sale	1,537,397		1,721,944
Securities held-to-maturity	706,748		493,230
Non-marketable equity investments	43,467		40,695
Loans, net of allowance for loan losses and unearned fees
Covered assets, net of allowance for covered loan losses
Accrued interest receivable
Investment in BOLI
Capital markets derivative assets	101,486		100,849
Deposits	7,852,083		8,217,765
Short-term borrowings	335,212		156,047
Long-term debt	11,532		16,893
Accrued interest payable
Capital markets derivative liabilities	105,729		104,108
Fair Value, Inputs, Level 3 [Member]
Estimated Fair Value Of Financial Instruments [Line Items]
Cash and due from banks
Federal funds sold and other short-term investments
Loans held for sale
Securities available-for-sale
Securities held-to-maturity
Non-marketable equity investments	4,235		2,909
Loans, net of allowance for loan losses and unearned fees	9,119,121		8,465,358
Covered assets, net of allowance for covered loan losses	243,600		306,976
Accrued interest receivable	37,089		35,732
Investment in BOLI	51,751		50,966
Capital markets derivative assets	1,127		827
Deposits	2,893,708		2,187,393
Short-term borrowings
Long-term debt	191,591		326,228
Accrued interest payable	5,855		5,567
Capital markets derivative liabilities	44		32
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Estimated Fair Value Of Financial Instruments [Line Items]
Cash and due from banks	141,563		156,131
Federal funds sold and other short-term investments	315,378		205,610
Loans held for sale	35,342		32,049
Securities available-for-sale	1,625,649		1,783,465
Securities held-to-maturity	693,277		490,143
Non-marketable equity investments	47,702		43,604
Loans, net of allowance for loan losses and unearned fees	9,261,933		8,816,967
Covered assets, net of allowance for covered loan losses	223,049		280,868
Accrued interest receivable	37,089		35,732
Investment in BOLI	51,751		50,966
Capital markets derivative assets	102,613		101,676
Deposits	10,734,530		10,392,854
Short-term borrowings	335,000		156,000
Long-term debt	374,793		379,793
Accrued interest payable	5,855		5,567
Capital markets derivative liabilities	$ 105,773		$ 104,140

[1] Capital market derivative assets and derivative liabilities include client-related derivatives.