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Commitments, Contingencies and Guarantees (Narrative) (Details)	9 Months Ended
	Sep. 30, 2019 USD ($)
Commitments, Contingencies And Guarantees [Abstract]
Aggregate loss on securities	$ 42,000,000
Maximum aggregate loss, if securities' price falls to zero and no debts collected	51,000,000
Guarantees, Fair Value Disclosure	$ 0

X

- Definition

Maximum Aggregate Loss, If Securities' Price Falls To Zero And No Debts Collected

+ References

No definition available.

+ Details

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- References

No definition available.

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- Definition

Fair value portion of guarantee, including, but not limited to, financial standby letter of credit, fair value guarantee, guarantee of collection of scheduled contractual cash flows from financial assets, and contracts that contingently require the guarantor to make payments or perform services.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12201-110248

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- Definition

Amount of unrealized and realized gain (loss) on investment in marketable security, including other-than-temporary impairment (OTTI).

+ References

No definition available.

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