Derivatives (Narrative) (Details) MMBTU in Thousands, Boe in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($) MMBTU Boe warrant	Dec. 31, 2017 USD ($) warrant
Derivative [Line Items]
Derivative liabilities - Fair Value	$ 118,305	$ 75,838
Derivative assets - Fair value	107,816	67,077
Foreign exchange contracts
Derivative [Line Items]
Notional amount		95,200
Derivative liability		7,200
Credit-Risk-Related Contingent Features
Derivative [Line Items]
Derivative asset	2,800	159
Derivative liability	14,200	7,800
Collateral Already Posted, Aggregate Fair Value	9,400	7,300
Aggregate fair value of derivative instruments in net liability position	11,400	7,600
Derivative instruments designated as hedging instruments
Derivative [Line Items]
Notional amount	126,056	35,811
Derivative liabilities - Fair Value	6,477	6,770
Derivative assets - Fair value	0	0
Derivative instruments designated as hedging instruments \| Foreign exchange contracts
Derivative [Line Items]
Notional amount	90,245	0
Derivative liabilities - Fair Value	611	0
Derivative assets - Fair value	0	0
Derivative instruments designated as hedging instruments \| Interest rate contracts
Derivative [Line Items]
Notional amount	35,811	35,811
Derivative liabilities - Fair Value	5,866	6,770
Derivative assets - Fair value	0	0
Derivative instruments not designated as hedging instruments
Derivative [Line Items]
Notional amount	15,222,341	10,153,108
Derivative liabilities - Fair Value	111,828	69,068
Derivative assets - Fair value	107,816	67,077
Derivative instruments not designated as hedging instruments \| Foreign exchange contracts
Derivative [Line Items]
Notional amount	3,407,522	770,215
Derivative liabilities - Fair Value	19,329	10,170
Derivative assets - Fair value	21,624	5,840
Derivative instruments not designated as hedging instruments \| Interest rate contracts
Derivative [Line Items]
Notional amount	11,695,499	9,333,860
Derivative liabilities - Fair Value	69,267	58,890
Derivative assets - Fair value	69,818	59,564
Derivative instruments not designated as hedging instruments \| Credit contracts
Derivative [Line Items]
Notional amount	119,320	49,033
Derivative liabilities - Fair Value	$ 164	$ 8
Weighted average remaining maturity	6 years 7 months 6 days	6 years
Derivative assets - Fair value	$ 1	$ 1
Derivative instruments not designated as hedging instruments \| Credit contracts \| RPAs - protection sold
Derivative [Line Items]
Maximum exposure of RPAs with protection sold	$ 125	$ 419
Derivative instruments not designated as hedging instruments \| Equity, Private Companies
Derivative [Line Items]
Number of companies that Issued the equity contracts (Issuers Portion Only) \| warrant	18	12
Derivative instruments not designated as hedging instruments \| Equity, Public Companies
Derivative [Line Items]
Number of companies that Issued the equity contracts (Issuers Portion Only) \| warrant	4	4
Derivative instruments not designated as hedging instruments \| Equity contracts
Derivative [Line Items]
Notional amount	$ 0	$ 0
Derivative liabilities - Fair Value	0	0
Derivative assets - Fair value	1,951	1,672
Derivative instruments not designated as hedging instruments \| Commodity contracts
Derivative [Line Items]
Notional amount	0	0
Derivative liabilities - Fair Value	23,068	0
Derivative assets - Fair value	14,422	0
Fair Value, Measurements, Recurring
Derivative [Line Items]
Derivative liabilities - Fair Value	118,305	75,838
Derivative assets - Fair value	107,816	67,077
Fair Value, Measurements, Recurring \| Foreign exchange contracts
Derivative [Line Items]
Derivative liabilities - Fair Value	19,940	10,170
Derivative assets - Fair value	21,624	5,840
Fair Value, Measurements, Recurring \| Interest rate contracts
Derivative [Line Items]
Derivative liabilities - Fair Value	75,133	65,660
Derivative assets - Fair value	69,818	59,564
Fair Value, Measurements, Recurring \| Credit contracts
Derivative [Line Items]
Derivative liabilities - Fair Value	164	8
Derivative assets - Fair value	1	1
Fair Value, Measurements, Recurring \| Equity contracts
Derivative [Line Items]
Derivative assets - Fair value	1,951	$ 1,672
Fair Value, Measurements, Recurring \| Commodity contracts
Derivative [Line Items]
Derivative liabilities - Fair Value	23,068
Derivative assets - Fair value	14,422
London Clearing House (LCH) \| Derivative instruments not designated as hedging instruments \| Interest rate contracts
Derivative [Line Items]
Notional amount	1,660,000
Derivative asset	16,400
Derivative liability	16,000
Financial Counterparty \| Derivative instruments not designated as hedging instruments \| Interest rate contracts
Derivative [Line Items]
Notional amount	5,850,000
Chicago Mercantile Exchange (CME) \| Derivative instruments not designated as hedging instruments \| Commodity contracts
Derivative [Line Items]
Derivative asset	10,400
Derivative liability	582
Derivative assets (liabilities), at fair value	$ 622
Oil \| Chicago Mercantile Exchange (CME) \| Derivative instruments not designated as hedging instruments \| Commodity contracts
Derivative [Line Items]
Derivative, nonmonetary notional amount, energy measure \| Boe	778
Natural Gas \| Chicago Mercantile Exchange (CME) \| Derivative instruments not designated as hedging instruments \| Commodity contracts
Derivative [Line Items]
Derivative, nonmonetary notional amount, energy measure \| MMBTU	6,290

Number of Companies that Issued the Warrants (Issuers Portion Only)

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Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

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-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

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Maximum potential amount of future undiscounted payments that could be required under the credit derivative, before reduction for potential recoveries under recourse or collateralization provisions.

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Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

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Average remaining period until maturity of the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

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Nominal energy measure used to calculate payments on a derivative instrument.

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