Derivative Financial Instruments - Balance Sheet Offsetting, Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Derivative Assets
Gross Amounts of Recognized Assets	$ 105,532	$ 108,901
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	105,532	108,901
Financial Instruments (Collateral)	(45,992)	(47,242)
Cash Collateral Received	(14,455)	(11,998)
Net Amount	45,085	49,661
Reverse repurchase, securities borrowing, and similar arrangements
Gross Amounts of Recognized Assets	298,755	123,611
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	298,755	123,611
Financial Instruments (Collateral)	(298,755)	(123,611)
Cash Collateral Received	0	0
Net Amount	0	0
Total
Gross Amounts of Recognized Assets	404,287	232,512
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	404,287	232,512
Financial Instruments (Collateral)	(344,747)	(170,853)
Cash Collateral Received	(14,455)	(11,998)
Net Amount	45,085	49,661
Interest rate swaps
Derivative Assets
Gross Amounts of Recognized Assets	1,408
Gross Amounts offset in the Statement of Financial Position	0
Net Amounts of Assets Presented in the Statement of Financial Position	1,408
Financial Instruments (Collateral)	(1,408)
Cash Collateral Received	0
Net Amount	0
Foreign exchange forwards
Derivative Assets
Gross Amounts of Recognized Assets	91,028	98,643
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	91,028	98,643
Financial Instruments (Collateral)	(32,638)	(38,213)
Cash Collateral Received	(13,991)	(11,825)
Net Amount	44,399	48,605
Client foreign currency options
Derivative Assets
Gross Amounts of Recognized Assets	1,333	1,759
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	1,333	1,759
Financial Instruments (Collateral)	(222)	(613)
Cash Collateral Received	(425)	(90)
Net Amount	686	1,056
Client interest rate derivatives
Derivative Assets
Gross Amounts of Recognized Assets	11,763	8,499
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	11,763	8,499
Financial Instruments (Collateral)	(11,724)	(8,416)
Cash Collateral Received	(39)	(83)
Net Amount	$ 0	$ 0