Collateralized Transactions (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Securities received as collateral:
Securities borrowed	$ 1,374,266	$ 1,881,005
Securities purchased under agreements to resell	22,866	142,922
Securities received as collateral	1,397,132	2,023,927
Financial instruments owned and pledged	746,539	696,956
Equities
Securities received as collateral:
Financial instruments owned and pledged	734,024	654,366
Exchange traded notes
Securities received as collateral:
Financial instruments owned and pledged	$ 12,515	$ 42,590

The total of collateralized agreements including securities purchased under agreements to resell (repos), borrowed securities, and secured demand notes.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(m)(2)(i)(A))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 10
-Section 05
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=109246787&loc=d3e93640-111703

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- Definition

The fair value of federal funds sold and securities purchased under agreements to resell that serve as collateral for borrowings.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729

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- Definition

The fair value as of the balance sheet date of financial instruments and other positions owned by the entity and pledged to counterparties as collateral, including: (1) mortgages, mortgage-backed and asset backed securities; (2) US government and agency obligations; (3) state and municipal government obligations; (4) other sovereign government debt; (5) corporate obligations; (6) corporate equities; (7) principal investments; (8) derivative contracts; and (9) physical commodities.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66007379&loc=d3e113888-111728

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-Publisher FASB
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-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (c)(2)
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Amount, after the effects of master netting arrangements, of securities borrowed from entities in exchange for collateral. Includes assets not subject to a master netting arrangement and not elected to be offset, at market value.

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