Derivative Financial Instruments - Total Notional or Contractual Amounts, Fair Value, Collateral and Net Exposure of Derivative Financial Instruments (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Maximum length of time over which forecasted transactions are hedged	6 years
Derivative [Line Items]
Fair Value, Derivative Assets	$ 133,460	$ 108,901
Fair Value, Derivative Liabilities	112,651	98,050
Derivative Assets, Total	291,508	258,139
Derivative Liabilities, Total	112,651	98,050
Interest rate swaps
Derivative [Line Items]
Fair Value, Derivative Assets	19,558
Fair Value, Derivative Liabilities	391
Foreign exchange forwards
Derivative [Line Items]
Fair Value, Derivative Assets	93,704	98,643
Fair Value, Derivative Liabilities	85,699	86,800
Client foreign currency options
Derivative [Line Items]
Fair Value, Derivative Assets	758	1,759
Fair Value, Derivative Liabilities	758	1,759
Client interest rate derivatives
Derivative [Line Items]
Fair Value, Derivative Assets	19,440	8,499
Fair Value, Derivative Liabilities	25,803	9,491
Derivatives designated as hedging instruments | Interest rate swaps | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	1,015,000	0
Fair Value, Derivative Assets	19,558	0
Derivatives designated as hedging instruments | Interest rate swaps | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	250,000	0
Fair Value, Derivative Liabilities	391	0
Derivatives not designated as hedging instruments
Derivative [Line Items]
Fair Value, Derivative Assets	271,950	258,139
Fair Value, Derivative Liabilities	112,260	98,050
Derivatives not designated as hedging instruments | Foreign exchange forwards | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	37,120	263,733
Fair Value, Derivative Assets	1,081	4,767
Derivatives not designated as hedging instruments | Foreign exchange forwards | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	275,704	178,310
Fair Value, Derivative Liabilities	4,210	1,094
Derivatives not designated as hedging instruments | Equity warrant assets | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	221,013	223,532
Fair Value, Derivative Assets	158,048	149,238
Derivatives not designated as hedging instruments | Client foreign exchange forwards | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	3,447,213	2,759,878
Fair Value, Derivative Assets	92,623	93,876
Derivatives not designated as hedging instruments | Client foreign exchange forwards | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	3,137,742	2,568,085
Fair Value, Derivative Liabilities	81,489	85,706
Derivatives not designated as hedging instruments | Client foreign currency options | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	87,439	93,556
Fair Value, Derivative Assets	758	1,759
Derivatives not designated as hedging instruments | Client foreign currency options | Other liability
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	87,538	93,579
Fair Value, Derivative Liabilities	758	1,759
Derivatives not designated as hedging instruments | Client interest rate derivatives | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	1,159,613	1,020,416
Fair Value, Derivative Assets	19,440	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	1,237,704	1,337,328
Fair Value, Derivative Liabilities	25,803	$ 9,491
Reduction in derivative liabilities due to rules of clearing houses	$ (4,200)