Derivative Financial Instruments - Total Notional or Contractual Amounts, Fair Value, Collateral and Net Exposure of Derivative Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Derivative [Line Items]
Fair Value	$ 84,569		$ 84,829
Net Exposure	77,109	[1]	78,719	[1]
Collateral	7,460	[2]	6,110	[2]
Derivatives designated as hedging instruments | Interest rate risks | Interest rate swaps | Other assets
Derivative [Line Items]
Notional or Contractual Amount	45,964		45,964
Fair Value	8,506		9,005
Net Exposure	1,046	[1]	2,895	[1]
Collateral	7,460	[2]	6,110	[2]
Derivatives not designated as hedging instruments | Currency exchange risks
Derivative [Line Items]
Fair Value	(372)		(1,240)
Net Exposure	(372)	[1]	(1,240)	[1]
Derivatives not designated as hedging instruments | Currency exchange risks | Foreign exchange forwards | Other assets
Derivative [Line Items]
Notional or Contractual Amount	46,088		51,010
Fair Value	1,051		488
Net Exposure	1,051	[1]	488	[1]
Derivatives not designated as hedging instruments | Currency exchange risks | Foreign exchange forwards | Other liability
Derivative [Line Items]
Notional or Contractual Amount	90,536		102,956
Fair Value	(1,423)		(1,728)
Net Exposure	(1,423)	[1]	(1,728)	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Equity warrant assets | Other assets
Derivative [Line Items]
Notional or Contractual Amount	169,303		164,332
Fair Value	72,333		74,272
Net Exposure	72,333	[1]	74,272	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives
Derivative [Line Items]
Fair Value	4,102		2,792
Net Exposure	4,102	[1]	2,792	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign exchange forwards | Other assets
Derivative [Line Items]
Notional or Contractual Amount	425,503		385,470
Fair Value	12,216		11,864
Net Exposure	12,216	[1]	11,864	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign exchange forwards | Other liability
Derivative [Line Items]
Notional or Contractual Amount	363,247		356,026
Fair Value	(9,605)		(9,930)
Net Exposure	(9,605)	[1]	(9,930)	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client foreign currency options | Other assets
Derivative [Line Items]
Notional or Contractual Amount	91,765		132,237
Fair Value	485		1,189
Net Exposure	485	[1]	1,189	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client foreign currency options | Other liability
Derivative [Line Items]
Notional or Contractual Amount	91,765		132,237
Fair Value	(485)		(1,189)
Net Exposure	(485)	[1]	(1,189)	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Loan conversion options | Other assets
Derivative [Line Items]
Notional or Contractual Amount	9,789		9,782
Fair Value	1,529		890
Net Exposure	1,529	[1]	890	[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	153,074		144,950
Fair Value	653		558
Net Exposure	653	[1]	558	[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	153,074		144,950
Fair Value	(691)		(590)
Net Exposure	$ (691)	[1]	$ (590)	[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 March 31, 2013 remain at investment grade or higher and there were no material changes in their credit ratings for the quarter ended March 31, 2013.

[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.