Derivative Financial Instruments - Total Notional or Contractual Amounts, Fair Value, Collateral and Net Exposure of Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Fair Value, Net Total	$ 134,430	$ 144,346
Net Exposure, Net	134,430	142,446
Collateral	0	1,900
Derivatives designated as hedging instruments | Interest rate risks | Other assets | Interest rate swaps
Derivative [Line Items]
Notional or Contractual Amount	45,964	45,964
Fair Value, Assets	2,400	2,768
Net Exposure, Assets	2,400	2,768
Collateral	0	0
Derivatives not designated as hedging instruments | Currency exchange risks
Derivative [Line Items]
Fair Value, Net exposure	(2,626)	140
Net Exposure, Net	(2,626)	140
Collateral	0	0
Derivatives not designated as hedging instruments | Currency exchange risks | Other assets | Foreign exchange forwards
Derivative [Line Items]
Notional or Contractual Amount	17,808	49,287
Fair Value, Assets	306	809
Net Exposure, Assets	306	809
Collateral	0	0
Derivatives not designated as hedging instruments | Currency exchange risks | Other liability | Foreign exchange forwards
Derivative [Line Items]
Notional or Contractual Amount	78,440	6,586
Fair value, Liabilities	(2,932)	(669)
Net Exposure, Liabilities	(2,932)	(669)
Collateral	0	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivative contracts
Derivative [Line Items]
Fair Value, Net exposure	3,986	4,333
Net Exposure, Net	3,986	2,433
Collateral	0	1,900
Derivatives not designated as hedging instruments | Other derivative instruments | Other assets | Equity warrant assets
Derivative [Line Items]
Notional or Contractual Amount	207,504	210,102
Fair Value, Assets	130,670	137,105
Net Exposure, Assets	130,670	137,105
Collateral	0	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other assets | Other derivative contracts | Foreign exchange forwards
Derivative [Line Items]
Notional or Contractual Amount	1,369,777	935,514
Fair Value, Assets	46,713	29,722
Net Exposure, Assets	46,713	27,822
Collateral	0	1,900
Derivatives not designated as hedging instruments | Other derivative instruments | Other assets | Other derivative contracts | Client foreign currency options
Derivative [Line Items]
Notional or Contractual Amount	30,568	46,625
Fair Value, Assets	600	706
Net Exposure, Assets	600	706
Collateral	0	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other assets | Other derivative contracts | Client interest rate derivatives
Derivative [Line Items]
Notional or Contractual Amount	299,750	422,741
Fair Value, Assets	6,432	3,973
Net Exposure, Assets	6,432	3,973
Collateral	0	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other liability | Other derivative contracts | Foreign exchange forwards
Derivative [Line Items]
Notional or Contractual Amount	1,160,600	841,182
Fair value, Liabilities	(41,896)	(24,978)
Net Exposure, Liabilities	(41,896)	(24,978)
Collateral	0	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other liability | Other derivative contracts | Client foreign currency options
Derivative [Line Items]
Notional or Contractual Amount	30,568	46,625
Fair value, Liabilities	(600)	(706)
Net Exposure, Liabilities	(600)	(706)
Collateral	0	0
Derivatives not designated as hedging instruments | Other derivative instruments | Other liability | Other derivative contracts | Client interest rate derivatives
Derivative [Line Items]
Notional or Contractual Amount	339,685	422,741
Fair value, Liabilities	(7,263)	(4,384)
Net Exposure, Liabilities	(7,263)	(4,384)
Collateral	$ 0	$ 0