Derivative Financial Instruments - Total Notional or Contractual Amounts, Fair Value, Collateral and Net Exposure of Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Fair Value, Net Total	$ 137,922	$ 144,346
Collateral	3,219	1,900
Net Exposure, Net	134,703	142,446
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	1,918	2,768
Collateral	0	0
Net Exposure, Assets	1,918	2,768
Derivatives not designated as hedging instruments | Currency exchange risks
Derivative [Line Items]
Fair Value, Net exposure	518	140
Collateral	1,230	0
Net Exposure, Net	(712)	140
Derivatives not designated as hedging instruments | Currency exchange risks | Other assets | Foreign exchange forwards
Derivative [Line Items]
Notional or Contractual Amount	41,845	49,287
Fair value, Assets	1,546	809
Collateral	1,230	0
Net Exposure, Assets	316	809
Derivatives not designated as hedging instruments | Currency exchange risks | Other liability | Foreign exchange forwards
Derivative [Line Items]
Notional or Contractual Amount	111,614	6,586
Fair value, Liabilities	(1,028)	(669)
Collateral	0	0
Net Exposure, Liabilities	(1,028)	(669)
Derivatives not designated as hedging instruments | Other derivative instruments | Other derivative contracts
Derivative [Line Items]
Fair Value, Net exposure	5,686	4,333
Collateral	1,989	1,900
Net Exposure, Net	3,697	2,433
Derivatives not designated as hedging instruments | Other derivative instruments | Other assets | Equity warrant assets
Derivative [Line Items]
Notional or Contractual Amount	208,551	210,102
Fair value, Assets	129,800	137,105
Collateral	0	0
Net Exposure, Assets	129,800	137,105
Derivatives not designated as hedging instruments | Other derivative instruments | Other assets | Other derivative contracts | Foreign exchange forwards
Derivative [Line Items]
Notional or Contractual Amount	1,468,046	935,514
Fair value, Assets	49,685	29,722
Collateral	1,989	1,900
Net Exposure, Assets	47,696	27,822
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	102,017	46,625
Fair value, Assets	1,614	706
Collateral	0	0
Net Exposure, Assets	1,614	706
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	349,123	422,741
Fair value, Assets	8,554	3,973
Collateral	0	0
Net Exposure, Assets	8,554	3,973
Derivatives not designated as hedging instruments | Other derivative instruments | Other liability | Other derivative contracts | Foreign exchange forwards
Derivative [Line Items]
Notional or Contractual Amount	1,151,920	841,182
Fair value, Liabilities	(42,898)	(24,978)
Collateral	0	0
Net Exposure, Liabilities	(42,898)	(24,978)
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	102,017	46,625
Fair value, Liabilities	(1,614)	(706)
Collateral	0	0
Net Exposure, Liabilities	(1,614)	(706)
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	389,079	422,741
Fair value, Liabilities	(9,655)	(4,384)
Collateral	0	0
Net Exposure, Liabilities	$ (9,655)	$ (4,384)