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Derivatives - Derivatives Associated with Fixed Income Trading Activities (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Customer Interest Rate Contracts |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional | $ 2,697,522 | $ 2,271,448
Assets | 65,768 | 18,744
Liabilities | 6,858 | 27,768
Offsetting Upstream Interest Rate Contracts |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional | 2,697,522 | 2,271,448
Assets | 2,583 | 4,014
Liabilities | 3,994 | 9,041
Option Contracts Purchased | Long |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional | 40,000 | 20,000
Assets | 131 | 25
Liabilities | 0 | 0
Forwards and Futures Purchased |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional | 9,217,350 | 4,684,177
Assets | 17,029 | 28,304
Liabilities | 3,187 | 181
Forwards and Futures Sold |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |
Notional | 9,403,112 | 4,967,454
Assets | 3,611 | 522
Liabilities | $ 16,620 | $ 30,055

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