Derivatives (Notional and Fair Values) (Details) MMBTU in Thousands, Boe in Thousands, $ in Thousands	Sep. 30, 2018 USD ($) Boe MMBTU warrant	Dec. 31, 2017 USD ($) warrant
Derivative Instruments
Derivative assets - Fair value	$ 99,103	$ 66,146
Derivative liabilities - Fair value	133,702	74,935
Foreign exchange contracts
Derivative Instruments
Notional amount		95,200
Derivatives designated as hedging instruments
Derivative Instruments
Notional amount	120,647	35,811
Derivative assets - Fair value	61	0
Derivative liabilities - Fair value	7,696	6,799
Derivatives designated as hedging instruments \| Interest rate contracts
Derivative Instruments
Notional amount	31,026	35,811
Derivative assets - Fair value	0	0
Derivative liabilities - Fair value	7,696	6,799
Derivatives designated as hedging instruments \| Foreign exchange contracts
Derivative Instruments
Notional amount	89,621	0
Derivative assets - Fair value	61	0
Derivative liabilities - Fair value	0	0
Derivatives not designated as hedging instruments
Derivative Instruments
Notional amount	13,254,731	10,153,108
Derivative assets - Fair value	99,042	66,146
Derivative liabilities - Fair value	126,006	68,136
Derivatives not designated as hedging instruments \| Interest rate contracts
Derivative Instruments
Notional amount	11,729,334	9,333,860
Derivative assets - Fair value	72,618	58,633
Derivative liabilities - Fair value	106,962	57,958
Derivatives not designated as hedging instruments \| Foreign exchange contracts
Derivative Instruments
Notional amount	1,405,339	770,215
Derivative assets - Fair value	11,034	5,840
Derivative liabilities - Fair value	11,075	10,170
Derivatives not designated as hedging instruments \| Credit contracts
Derivative Instruments
Notional amount	120,058	49,033
Derivative assets - Fair value	1	1
Derivative liabilities - Fair value	57	8
Derivatives not designated as hedging instruments \| Equity contracts
Derivative Instruments
Notional amount	0	0
Derivative assets - Fair value	2,409	1,672
Derivative liabilities - Fair value	$ 0	$ 0
Derivatives not designated as hedging instruments \| Warrant, Public Companies
Derivative Instruments
Number of companies that issued the warrants (issuers portion only) \| warrant	4	4
Derivatives not designated as hedging instruments \| Warrant, Private Companies
Derivative Instruments
Number of companies that issued the warrants (issuers portion only) \| warrant	17	11
Derivatives not designated as hedging instruments \| Commodity contracts
Derivative Instruments
Notional amount	$ 0	$ 0
Derivative assets - Fair value	12,980	0
Derivative liabilities - Fair value	$ 7,912	$ 0
Oil
Derivative Instruments
Derivative, nonmonetary notional amount \| Boe	2,667
Natural gas
Derivative Instruments
Derivative, nonmonetary notional amount \| MMBTU	9,860

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

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- Definition

Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and elected not to be offset.

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