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	Jun. 30, 2013		Dec. 31, 2012
Derivative [Line Items]
Fair Value	$ 90,491		$ 84,829
Net Exposure	85,091	[1]	78,719	[1]
Collateral	5,400	[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	7,224		9,005
Net Exposure	1,824	[1]	2,895	[1]
Collateral	5,400	[2]	6,110	[2]
Derivatives not designated as hedging instruments | Currency exchange risks
Derivative [Line Items]
Fair Value	1,859		(1,240)
Net Exposure	1,859	[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	105,162		51,010
Fair Value	1,899		488
Net Exposure	1,899	[1]	488	[1]
Derivatives not designated as hedging instruments | Currency exchange risks | Foreign exchange forwards | Other liability
Derivative [Line Items]
Notional or Contractual Amount	47,834		102,956
Fair Value	(40)		(1,728)
Net Exposure	(40)	[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	173,299		164,332
Fair Value	76,584		74,272
Net Exposure	76,584	[1]	74,272	[1]
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives
Derivative [Line Items]
Fair Value	4,824		2,792
Net Exposure	4,824	[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	449,340		385,470
Fair Value	14,281		11,864
Net Exposure	14,281	[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	399,527		356,026
Fair Value	(11,043)		(9,930)
Net Exposure	(11,043)	[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	85,200		132,237
Fair Value	215		1,189
Net Exposure	215	[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	85,200		132,237
Fair Value	(215)		(1,189)
Net Exposure	(215)	[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	9,430		9,782
Fair Value	1,595		890
Net Exposure	1,595	[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	151,022		144,950
Fair Value	136		558
Net Exposure	136	[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	151,022		144,950
Fair Value	(145)		(590)
Net Exposure	$ (145)	[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 June 30, 2013 remain at investment grade or higher and there were no material changes in their credit ratings during the three and six months ended June 30, 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.