Derivative Financial Instruments - Total Notional or Contractual Amounts, Fair Value, Collateral and Net Exposure of Derivative Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Maximum length of time over which forecasted transactions are hedged	5 years
Derivative [Line Items]
Fair Value, Derivative Assets	$ 105,532	$ 108,901
Fair Value, Derivative Liabilities	91,612	98,050
Derivative Assets, Total	267,747	258,139
Derivative Liabilities, Total	91,612	98,050
Interest rate swaps
Derivative [Line Items]
Fair Value, Derivative Assets	1,408
Fair Value, Derivative Liabilities	303
Foreign exchange forwards
Derivative [Line Items]
Fair Value, Derivative Assets	91,028	98,643
Fair Value, Derivative Liabilities	81,132	86,800
Client foreign currency options
Derivative [Line Items]
Fair Value, Derivative Assets	1,333	1,759
Fair Value, Derivative Liabilities	1,336	1,759
Client interest rate derivatives
Derivative [Line Items]
Fair Value, Derivative Assets	11,763	8,499
Fair Value, Derivative Liabilities	8,841	9,491
Derivatives designated as hedging instruments | Interest rate swaps | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	165,000	0
Fair Value, Derivative Assets	1,408	0
Derivatives designated as hedging instruments | Interest rate swaps | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	200,000	0
Fair Value, Derivative Liabilities	303	0
Derivatives not designated as hedging instruments
Derivative [Line Items]
Fair Value, Derivative Assets	266,339	258,139
Fair Value, Derivative Liabilities	91,309	98,050
Derivatives not designated as hedging instruments | Foreign exchange forwards | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	180,055	263,733
Fair Value, Derivative Assets	3,312	4,767
Derivatives not designated as hedging instruments | Foreign exchange forwards | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	184,353	178,310
Fair Value, Derivative Liabilities	2,845	1,094
Derivatives not designated as hedging instruments | Equity warrant assets | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	226,734	223,532
Fair Value, Derivative Assets	162,215	149,238
Derivatives not designated as hedging instruments | Client foreign exchange forwards | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	2,907,771	2,759,878
Fair Value, Derivative Assets	87,716	93,876
Derivatives not designated as hedging instruments | Client foreign exchange forwards | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	2,779,090	2,568,085
Fair Value, Derivative Liabilities	78,287	85,706
Derivatives not designated as hedging instruments | Client foreign currency options | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	91,808	93,556
Fair Value, Derivative Assets	1,333	1,759
Derivatives not designated as hedging instruments | Client foreign currency options | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	91,908	93,579
Fair Value, Derivative Liabilities	1,336	1,759
Derivatives not designated as hedging instruments | Client interest rate derivatives | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	1,198,257	1,020,416
Fair Value, Derivative Assets	11,763	8,499
Reduction in derivative assets due to rules of clearing houses		(400)
Derivatives not designated as hedging instruments | Client interest rate derivatives | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	1,274,564	1,337,328
Fair Value, Derivative Liabilities	8,841	$ 9,491
Reduction in derivative liabilities due to rules of clearing houses	$ (3,900)