Total Notional or Contractual Amounts, Fair Value, Collateral and Net Exposure of Derivative Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Derivative [Line Items]
Fair value	$ 90,524		$ 80,825
Collateral	5,880	[1]
Net Exposure	84,644	[2]	80,825	[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	9,331		11,441
Collateral	5,880	[1]
Net Exposure	3,451	[2]	11,441	[2]
Derivatives not designated as hedging instruments | Currency exchange risks
Derivative [Line Items]
Fair value	392		315
Net Exposure	392	[2]	315	[2]
Derivatives not designated as hedging instruments | Currency exchange risks | Foreign exchange forwards | Other assets
Derivative [Line Items]
Notional or Contractual Amount	53,158		68,518
Fair value	1,518		514
Net Exposure	1,518	[2]	514	[2]
Derivatives not designated as hedging instruments | Currency exchange risks | Foreign exchange forwards | Other liability
Derivative [Line Items]
Notional or Contractual Amount	45,505		6,822
Fair value	(1,126)		(199)
Net Exposure	(1,126)	[2]	(199)	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Equity Warrant Asset | Other assets
Derivative [Line Items]
Notional or Contractual Amount	156,784		144,586
Fair value	74,405		66,953
Net Exposure	74,405	[2]	66,953	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives
Derivative [Line Items]
Fair value	6,396		2,116
Net Exposure	6,396	[2]	2,116	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign exchange forwards | Other assets
Derivative [Line Items]
Notional or Contractual Amount	530,889		387,714
Fair value	18,317		17,541
Net Exposure	18,317	[2]	17,541	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign exchange forwards | Other liability
Derivative [Line Items]
Notional or Contractual Amount	388,394		366,835
Fair value	(13,488)		(16,346)
Net Exposure	(13,488)	[2]	(16,346)	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign currency options | Other assets
Derivative [Line Items]
Notional or Contractual Amount	97,943		75,600
Fair value	747		271
Net Exposure	747	[2]	271	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign currency options | Other liability
Derivative [Line Items]
Notional or Contractual Amount	97,943		75,600
Fair value	(747)		(271)
Net Exposure	(747)	[2]	(271)	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Loan conversion options | Other assets
Derivative [Line Items]
Notional or Contractual Amount	10,254		14,063
Fair value	1,569		923
Net Exposure	1,569	[2]	923	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client interest rate derivatives | Other assets
Derivative [Line Items]
Notional or Contractual Amount	38,588		39,713
Fair value	57		50
Net Exposure	57	[2]	50	[2]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client interest rate derivatives | Other liability
Derivative [Line Items]
Notional or Contractual Amount	38,588		39,713
Fair value	(59)		(52)
Net Exposure	$ (59)	[2]	$ (52)	[2]

[1] 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.

[2] 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 June 30, 2012 remain at investment grade or higher and there were no material changes in their credit ratings for the three and six months ended June 30, 2012.