Derivative Financial Instruments - Balance Sheet Offsetting, Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Derivative Assets
Gross Amounts of Recognized Assets	$ 188,864	$ 108,901
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	188,864	108,901
Financial Instruments (Collateral)	(96,267)	(47,242)
Cash Collateral Received	(18,898)	(11,998)
Net Amount	73,699	49,661
Reverse repurchase, securities borrowing, and similar arrangements
Gross Amounts of Recognized Assets	387,119	123,611
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	387,119	123,611
Financial Instruments (Collateral)	(387,119)	(123,611)
Cash Collateral Received	0	0
Net Amount	0	0
Total
Gross Amounts of Recognized Assets	575,983	232,512
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	575,983	232,512
Financial Instruments (Collateral)	(483,386)	(170,853)
Cash Collateral Received	(18,898)	(11,998)
Net Amount	73,699	49,661
Interest rate swaps
Derivative Assets
Gross Amounts of Recognized Assets	40,976
Gross Amounts offset in the Statement of Financial Position	0
Net Amounts of Assets Presented in the Statement of Financial Position	40,976
Financial Instruments (Collateral)	(9,286)
Cash Collateral Received	(13)
Net Amount	31,677
Foreign exchange forwards
Derivative Assets
Gross Amounts of Recognized Assets	120,795	98,643
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	120,795	98,643
Financial Instruments (Collateral)	(60,525)	(38,213)
Cash Collateral Received	(18,586)	(11,825)
Net Amount	41,684	48,605
Client foreign currency options
Derivative Assets
Gross Amounts of Recognized Assets	1,485	1,759
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	1,485	1,759
Financial Instruments (Collateral)	(848)	(613)
Cash Collateral Received	(299)	(90)
Net Amount	338	1,056
Client interest rate derivatives
Derivative Assets
Gross Amounts of Recognized Assets	25,608	8,499
Gross Amounts offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	25,608	8,499
Financial Instruments (Collateral)	(25,608)	(8,416)
Cash Collateral Received	0	(83)
Net Amount	$ 0	$ 0