Derivative Financial Instruments - Total Notional or Contractual Amounts, Fair Value, Collateral and Net Exposure of Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Derivative Assets	$ 319,815	$ 167,341
Derivative Liabilities	227,424	137,984
Derivative Assets, Total	472,525	332,814
Derivative Liabilities, Total	227,424	137,984
Reduction in derivative liabilities due to rules of clearing houses	55,700	17,400
Interest rate swaps
Derivative [Line Items]
Derivative Assets	0	22,676
Derivative Liabilities	0	25,623
Foreign exchange forwards
Derivative [Line Items]
Derivative Assets	232,549	114,546
Derivative Liabilities	189,168	96,899
Client foreign currency options
Derivative [Line Items]
Derivative Assets	6,723	1,308
Derivative Liabilities	6,723	1,308
Client interest rate derivatives
Derivative [Line Items]
Derivative Assets	80,543	28,811
Derivative Liabilities	31,533	14,154
Derivatives designated as hedging instruments | Interest rate swaps | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	0	1,915,000
Derivative Assets	0	22,676
Derivatives designated as hedging instruments | Interest rate swaps | Other liabilities
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	0	3,085,000
Derivative Liabilities	0	25,623
Derivatives not designated as hedging instruments
Derivative [Line Items]
Derivative Assets	472,525	310,138
Derivative Liabilities	227,424	112,361
Derivatives not designated as hedging instruments | Foreign exchange forwards | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	330,045	0
Derivative Assets	5,928	0
Derivatives not designated as hedging instruments | Foreign exchange forwards | Other liabilities
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	158,592	300,250
Derivative Liabilities	2,751	2,154
Derivatives not designated as hedging instruments | Equity warrant assets | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	235,074	225,893
Derivative Assets	152,710	165,473
Derivatives not designated as hedging instruments | Client foreign exchange forwards | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	6,914,487	4,661,517
Derivative Assets	226,621	114,546
Derivatives not designated as hedging instruments | Client foreign exchange forwards | Other liabilities
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	5,720,213	4,326,059
Derivative Liabilities	186,417	94,745
Derivatives not designated as hedging instruments | Client foreign currency options | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	237,349	154,985
Derivative Assets	6,723	1,308
Derivatives not designated as hedging instruments | Client foreign currency options | Other liabilities
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	237,349	154,985
Derivative Liabilities	6,723	1,308
Derivatives not designated as hedging instruments | Client interest rate derivatives | Other assets
Derivative [Line Items]
Derivative Asset, Notional or Contractual Amount	747,228	1,275,190
Derivative Assets	80,543	28,811
Derivatives not designated as hedging instruments | Client interest rate derivatives | Other liabilities
Derivative [Line Items]
Derivative Liabilities, Notional or Contractual Amount	829,528	1,372,914
Derivative Liabilities	$ 31,533	$ 14,154