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Derivatives (Net Gains (Losses) on Derivatives Not Designated as Hedging Instruments) (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
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Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Net gains (losses) recognized for derivative not designated as hedging instruments | $ 2,137 | $ 5,771 | $ 10,016 | $ 13,878
Interest rate contracts | Interest rate contracts and other derivative income |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Net gains (losses) recognized for derivative not designated as hedging instruments | (2,738) | 653 | (5,876) | 1,847
Foreign exchange contracts | Foreign exchange income |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Net gains (losses) recognized for derivative not designated as hedging instruments | 5,306 | 4,612 | 15,127 | 11,115
Credit contracts | Interest rate contracts and other derivative income |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Net gains (losses) recognized for derivative not designated as hedging instruments | (3) | 20 | 44 | (49)
Equity contracts | Lending fees |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Net gains (losses) recognized for derivative not designated as hedging instruments | (442) | 531 | 725 | 970
Commodity contracts | Interest rate contracts and other derivative income |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |
Net gains (losses) recognized for derivative not designated as hedging instruments | $ 14 | $ (45) | $ (4) | $ (5)

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- Definition Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4CC -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998890-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 + Details
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