Derivative Financial Instruments - Balance Sheet Offsetting, Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivative Assets
Gross Amounts of Recognized Assets	$ 133,460	$ 108,901
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	133,460	108,901
Financial Instruments (Collateral)	(69,657)	(47,242)
Cash Collateral Received	(24,252)	(11,998)
Net Amount	39,551	49,661
Reverse repurchase, securities borrowing, and similar arrangements
Gross Amounts of Recognized Assets	291,678	123,611
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	291,678	123,611
Financial Instruments (Collateral)	(291,678)	(123,611)
Cash Collateral Received	0	0
Net Amount	0	0
Total
Gross Amounts of Recognized Assets	425,138	232,512
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	425,138	232,512
Financial Instruments (Collateral)	(361,335)	(170,853)
Cash Collateral Received	(24,252)	(11,998)
Net Amount	39,551	49,661
Interest rate swaps
Derivative Assets
Gross Amounts of Recognized Assets	19,558
Gross Amounts offset in the Statement of Financial Position	0
Net Amounts of Assets Presented in the Statement of Financial Position	19,558
Financial Instruments (Collateral)	(19,558)
Cash Collateral Received	0
Net Amount	0
Foreign exchange forwards
Derivative Assets
Gross Amounts of Recognized Assets	93,704	98,643
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	93,704	98,643
Financial Instruments (Collateral)	(30,435)	(38,213)
Cash Collateral Received	(24,171)	(11,825)
Net Amount	39,098	48,605
Client foreign currency options
Derivative Assets
Gross Amounts of Recognized Assets	758	1,759
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	758	1,759
Financial Instruments (Collateral)	(246)	(613)
Cash Collateral Received	(59)	(90)
Net Amount	453	1,056
Client interest rate derivatives
Derivative Assets
Gross Amounts of Recognized Assets	19,440	8,499
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	19,440	8,499
Financial Instruments (Collateral)	(19,418)	(8,416)
Cash Collateral Received	(22)	(83)
Net Amount	$ 0	$ 0