Total Notional or Contractual Amounts, Fair Value, Collateral and Net Exposure of Derivative Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011
Derivative [Line Items]
Net Exposure Derivative Instruments	$ 75,685	[1]	$ 80,825	[1]
Fair value	81,855		80,825
Collateral	6,170	[2]	0	[2]
Derivatives designated as hedging instruments | Interest rate risks | Interest rate swaps | Other assets
Derivative [Line Items]
Notional or Contractual Amount	45,964		187,393
Fair value	9,508		11,441
Collateral	6,170	[2]	0	[2]
Net Exposure	3,338	[1]	11,441	[1]
Derivatives not designated as hedging instruments | Currency exchange risks
Derivative [Line Items]
Fair value	(825)		315
Net Exposure Derivative Instruments	(825)	[1]	315	[1]
Derivatives not designated as hedging instruments | Currency exchange risks | Foreign exchange forwards | Other assets
Derivative [Line Items]
Notional or Contractual Amount	23,441		68,518
Fair value	548		514
Net Exposure	548	[1]	514	[1]
Derivatives not designated as hedging instruments | Currency exchange risks | Foreign exchange forwards | Other liability
Derivative [Line Items]
Notional or Contractual Amount	38,593		6,822
Fair value	(1,373)		(199)
Net Exposure Derivative Instruments Liablities	(1,373)	[1]	(199)	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Equity Warrant Asset | Other assets
Derivative [Line Items]
Notional or Contractual Amount	162,471		144,586
Fair value	70,478		66,953
Net Exposure	70,478	[1]	66,953	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives
Derivative [Line Items]
Fair value	2,694		2,116
Net Exposure Derivative Instruments	2,694	[1]	2,116	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign exchange forwards | Other assets
Derivative [Line Items]
Notional or Contractual Amount	419,005		387,714
Fair value	11,581		17,541
Net Exposure	11,581	[1]	17,541	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign exchange forwards | Other liability
Derivative [Line Items]
Notional or Contractual Amount	393,426		366,835
Fair value	(10,116)		(16,346)
Net Exposure Derivative Instruments Liablities	(10,116)	[1]	(16,346)	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign currency options | Other assets
Derivative [Line Items]
Notional or Contractual Amount	127,379		75,600
Fair value	987		271
Net Exposure	(987)	[1]	271	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign currency options | Other liability
Derivative [Line Items]
Notional or Contractual Amount	127,379		75,600
Fair value	(987)		(271)
Net Exposure Derivative Instruments Liablities	(987)	[1]	(271)	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Loan conversion options | Other assets
Derivative [Line Items]
Notional or Contractual Amount	9,778		14,063
Fair value	1,240		923
Net Exposure	1,240	[1]	923	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client interest rate derivatives | Other assets
Derivative [Line Items]
Notional or Contractual Amount	62,120		39,713
Fair value	236		50
Net Exposure	236	[1]	50	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client interest rate derivatives | Other liability
Derivative [Line Items]
Notional or Contractual Amount	62,120		39,713
Fair value	(247)		(52)
Net Exposure Derivative Instruments Liablities	$ (247)	[1]	$ (52)	[1]

[1] Net exposure for contracts in a gain position reflects the replacement cost in the event of nonperformance by all such counterparties. The credit ratings of our institutional counterparties as of September 30, 2012 remain at investment grade or higher and there were no material changes in their credit ratings for the three and nine months ended September 30, 2012

[2] Cash collateral received from our counterparty for our interest rate swap agreement is recorded as a component of “short-term borrowings” on our consolidated balance sheets.