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Derivatives (Derivatives Not Designated as Hedging Instruments - Foreign Exchange Contracts) (Details) - USD ($) $ in Thousands | Jun. 30, 2019 | Dec. 31, 2018
--- | --- | ---
Derivative [Line Items] |  |
Derivative assets - Fair value | $ 242,876 | $ 107,816
Derivative liabilities - Fair value | 172,923 | 118,305
Derivatives not designated as hedging instruments |  |
Derivative [Line Items] |  |
Notional amount | 16,986,784 | 15,222,341
Derivative assets - Fair value | 242,824 | 107,816
Derivative liabilities - Fair value | 169,904 | 111,828
Derivatives not designated as hedging instruments | Foreign exchange contracts |  |
Derivative [Line Items] |  |
Notional amount | 3,425,107 | 3,407,522
Derivative assets - Fair value | 27,797 | 21,624
Derivative liabilities - Fair value | 22,528 | 19,329
Foreign exchange contracts | Customer Counterparty | Derivatives not designated as hedging instruments | Forwards and spot |  |
Derivative [Line Items] |  |
Notional amount | 2,036,792 | 2,023,425
Derivative assets - Fair value | 18,941 | 11,719
Derivative liabilities - Fair value | 16,358 | 13,079
Foreign exchange contracts | Customer Counterparty | Derivatives not designated as hedging instruments | Swaps |  |
Derivative [Line Items] |  |
Notional amount | 17,348 | 21,108
Derivative assets - Fair value | 374 | 348
Derivative liabilities - Fair value | 101 | 243
Foreign exchange contracts | Customer Counterparty | Derivatives not designated as hedging instruments | Written options |  |
Derivative [Line Items] |  |
Notional amount | 88,758 | 537
Derivative assets - Fair value | 422 | 16
Derivative liabilities - Fair value | 0 | 0
Foreign exchange contracts | Customer Counterparty | Derivatives not designated as hedging instruments | Collars |  |
Derivative [Line Items] |  |
Notional amount | 88,863 | 83,864
Derivative assets - Fair value | 288 | 0
Derivative liabilities - Fair value | 425 | 370
Foreign exchange contracts | Customer Counterparty | Derivatives not designated as hedging instruments | Foreign exchange contracts |  |
Derivative [Line Items] |  |
Notional amount | 2,231,761 | 2,128,934
Derivative assets - Fair value | 20,025 | 12,083
Derivative liabilities - Fair value | 16,884 | 13,692
Foreign exchange contracts | Financial Counterparty | Derivatives not designated as hedging instruments | Forwards and spot |  |
Derivative [Line Items] |  |
Notional amount | 246,962 | 506,342
Derivative assets - Fair value | 2,671 | 3,407
Derivative liabilities - Fair value | 454 | 2,285
Foreign exchange contracts | Financial Counterparty | Derivatives not designated as hedging instruments | Swaps |  |
Derivative [Line Items] |  |
Notional amount | 768,763 | 687,845
Derivative assets - Fair value | 4,676 | 5,764
Derivative liabilities - Fair value | 4,480 | 3,336
Foreign exchange contracts | Financial Counterparty | Derivatives not designated as hedging instruments | Purchased options |  |
Derivative [Line Items] |  |
Notional amount | 88,758 | 537
Derivative assets - Fair value | 0 | 0
Derivative liabilities - Fair value | 422 | 16
Foreign exchange contracts | Financial Counterparty | Derivatives not designated as hedging instruments | Collars |  |
Derivative [Line Items] |  |
Notional amount | 88,863 | 83,864
Derivative assets - Fair value | 425 | 370
Derivative liabilities - Fair value | 288 | 0
Foreign exchange contracts | Financial Counterparty | Derivatives not designated as hedging instruments | Foreign exchange contracts |  |
Derivative [Line Items] |  |
Notional amount | 1,193,346 | 1,278,588
Derivative assets - Fair value | 7,772 | 9,541
Derivative liabilities - Fair value | $ 5,644 | $ 5,637

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