Derivative Financial Instruments - Balance Sheet Offsetting, Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivative Liabilities
Gross Amounts of Recognized Liabilities	$ 112,651	$ 98,050
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	112,651	98,050
Financial Instruments (Collateral)	(17,962)	(25,832)
Cash Collateral Pledged	(54,875)	(29,939)
Net Amount	39,814	42,279
Repurchase, securities lending, and similar arrangements
Securities Sold under Agreements to Repurchase, Gross	0	319,414
Securities Sold under Agreements to Repurchase, Asset	0	0
Securities Sold under Agreements to Repurchase	0	319,414
Financial Instruments (Collateral)	0	0
Cash Collateral Pledged	0	0
Net Amount	0	319,414
Total
Gross Amounts of Recognized Liabilities	112,651	417,464
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	112,651	417,464
Financial Instruments (Collateral)	(17,962)	(25,832)
Cash Collateral Pledged	(54,875)	(29,939)
Net Amount	39,814	361,693
Interest rate swaps
Derivative Liabilities
Gross Amounts of Recognized Liabilities	391
Gross Amounts offset in the Statement of Financial Position	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	391
Financial Instruments (Collateral)	(391)
Cash Collateral Pledged	0
Net Amount	0
Foreign exchange forwards
Derivative Liabilities
Gross Amounts of Recognized Liabilities	85,699	86,800
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	85,699	86,800
Financial Instruments (Collateral)	(17,096)	(24,778)
Cash Collateral Pledged	(29,296)	(20,732)
Net Amount	39,307	41,290
Client foreign currency options
Derivative Liabilities
Gross Amounts of Recognized Liabilities	758	1,759
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	758	1,759
Financial Instruments (Collateral)	(475)	(1,054)
Cash Collateral Pledged	0	0
Net Amount	283	705
Client interest rate derivatives
Derivative Liabilities
Gross Amounts of Recognized Liabilities	25,803	9,491
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	25,803	9,491
Financial Instruments (Collateral)	0	0
Cash Collateral Pledged	(25,579)	(9,207)
Net Amount	$ 224	$ 284