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	Sep. 30, 2014		Dec. 31, 2013
Derivative [Line Items]
Fair Value	$ 101,182		$ 113,101
Net Exposure	94,552	[1]	108,021
Collateral	6,630	[2]	5,080
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	4,965		6,492
Net Exposure	1,055	[1]	1,412
Collateral	3,910	[2]	5,080
Derivatives not designated as hedging instruments | Currency exchange risks
Derivative [Line Items]
Fair Value	645		789
Net Exposure	(1,290)	[1]	789
Collateral	1,935	[2]	0
Derivatives not designated as hedging instruments | Currency exchange risks | Foreign exchange forwards | Other assets
Derivative [Line Items]
Notional or Contractual Amount	33,840		140,760
Fair Value	1,032		1,423
Net Exposure	(903)	[1]	1,423
Collateral	1,935	[2]	0
Derivatives not designated as hedging instruments | Currency exchange risks | Foreign exchange forwards | Other liability
Derivative [Line Items]
Notional or Contractual Amount	30,306		62,649
Fair Value	(387)		(634)
Net Exposure	(387)	[1]	(634)
Collateral	0	[2]	0
Derivatives not designated as hedging instruments | Other derivative instruments | Equity warrant assets | Other assets
Derivative [Line Items]
Notional or Contractual Amount	186,853		179,934
Fair Value	94,960		103,513
Net Exposure	94,960	[1]	103,513
Collateral	0	[2]	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives
Derivative [Line Items]
Fair Value	612		2,307
Net Exposure	(173)	[1]	2,307
Collateral	785	[2]	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign exchange forwards | Other assets
Derivative [Line Items]
Notional or Contractual Amount	526,329		424,983
Fair Value	16,111		13,673
Net Exposure	15,326	[1]	13,673
Collateral	785	[2]	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Foreign exchange forwards | Other liability
Derivative [Line Items]
Notional or Contractual Amount	483,262		367,079
Fair Value	(15,355)		(11,549)
Net Exposure	(15,355)	[1]	(11,549)
Collateral	0	[2]	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client foreign currency options | Other assets
Derivative [Line Items]
Notional or Contractual Amount	6,500		91,854
Fair Value	91		434
Net Exposure	91	[1]	434
Collateral	0	[2]	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client foreign currency options | Other liability
Derivative [Line Items]
Notional or Contractual Amount	6,500		91,854
Fair Value	(91)		(434)
Net Exposure	(91)	[1]	(434)
Collateral	0	[2]	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Loan conversion options | Other assets
Derivative [Line Items]
Notional or Contractual Amount	1,442		3,455
Fair Value	0		314
Net Exposure	0	[1]	314
Collateral	0	[2]	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client interest rate derivatives | Other assets
Derivative [Line Items]
Notional or Contractual Amount	359,074		216,773
Fair Value	2,173		1,265
Net Exposure	2,173	[1]	1,265
Collateral	0	[2]	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivatives | Client interest rate derivatives | Other liability
Derivative [Line Items]
Notional or Contractual Amount	359,074		216,773
Fair Value	(2,317)		(1,396)
Net Exposure	(2,317)	[1]	(1,396)
Collateral	$ 0	[2]	$ 0

[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, 2014 remain at investment grade or higher and there were no material changes in their credit ratings during the three and nine months ended September 30, 2014.

[2] Cash collateral received from our counterparties in relation to market value exposures of derivative contracts in our favor is recorded as a component of “short-term borrowings” on our consolidated balance sheets.