XML 74 R63.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Financial Instruments Owned And Financial Instruments Sold, But Not Yet Purchased (Narrative) (Details) - USD ($) $ in Millions | Jun. 30, 2018 | Dec. 31, 2017
--- | --- | ---
Schedule Of Trading Securities And Other Trading Assets [Line Items] |  |
Financial instruments pledged as collateral | $ 2,100.0 | $ 2,200.0
Securities Owned |  |
Schedule Of Trading Securities And Other Trading Assets [Line Items] |  |
Financial instruments pledged as collateral | $ 838.6 | $ 810.3

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of financial instrument held by the entity for its own account (proprietary securities) for trading or investment purposes that are carried at fair value and pledged to counterparties as collateral for financing transactions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 30 -Section 50 -Paragraph 1A -Subparagraph (b)(1)(i) -URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -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 + Details
Name: | us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=sf_SecuritiesOwnedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |