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Derivatives (Net Gains (Losses) on Derivatives Not Designated as Hedging Instruments) (Details) - Derivative instruments not designated as hedging instruments - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Net gains (losses) recognized for derivative not designated as hedging instruments | $ 20,808 | $ 17,409 | $ 21,969
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 | (2,126) | 280 | (1,772)
Foreign exchange contracts | Foreign exchange income |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Net gains (losses) recognized for derivative not designated as hedging instruments | 22,264 | 16,784 | 22,076
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 | 59 | (156) | (7)
Equity warrants | Lending fees |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Net gains (losses) recognized for derivative not designated as hedging instruments | 678 | 512 | 1,672
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 | $ (67) | $ (11) | $ 0

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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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