XML 67 R57.htm IDEA: XBRL DOCUMENT
v3.22.1

Fair Value Of Financial Instruments (Fair Value Of Assets And Liabilities Measured On Recurring Basis) (Details) - USD ($) $ in Thousands | Mar. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | $ 1,279,636 |  | $ 1,157,004 |
Available-for-sale securities |  | 1,926,144 | [1] | 2,113,893 |
Investments |  | 113,302 |  | 117,804 |
Cash equivalents measured at NAV |  | 3,383 |  | 3,004 |
Derivative contracts, Assets | [2] |  |  | 52,129 |
Total Assets |  | 3,397,111 |  | 3,443,834 |
Financial instruments sold, but not yet purchased, at fair value |  | 941,415 |  | 756,150 |
Derivative contracts, Liabilities |  | 74,658 | [3] | 52,147 | [4]
Total, Liabilities |  | 1,016,073 |  | 808,297 |
U.S. Government Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 60,821 |  | 10,774 |
Financial instruments sold, but not yet purchased, at fair value |  | 481,889 |  | 377,023 |
U.S. Government Agency Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 210,855 |  | 143,793 |
Available-for-sale securities |  | 2,922 | [1] | 1,808 |
Financial instruments sold, but not yet purchased, at fair value |  | 69,181 |  | 37,395 |
Asset-Backed Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 72,990 |  | 132,087 |
Available-for-sale securities |  | 265,680 |  | 291,054 |
Investments |  | 27,269 |  |  |
Corporate Fixed Income Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 258,717 |  | 255,999 |
Available-for-sale securities |  | 730,874 | [1] | 791,893 |
Financial instruments sold, but not yet purchased, at fair value |  | 198,815 |  | 153,852 |
Corporate Equity Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 73,050 |  | 75,056 |
Investments |  |  |  | 21,308 |
Financial instruments sold, but not yet purchased, at fair value |  | 22,485 |  | 28,482 |
State And Municipal Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 202,737 |  | 162,335 |
Available-for-sale securities |  | 2,366 | [1] | 2,399 |
Auction Rate Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments |  | 13,743 |  | 13,032 |
Other Investment [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments |  | 48,707 |  | 60,406 |
Investments in Funds and Partnerships Measured at NAV [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments |  | 23,583 |  | 23,058 |
Derivative contracts, Assets | [5] | 74,646 |  |  |
Agency Mortgage-Backed Securities [Member] | Agency Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 348,695 |  | 335,050 |
Available-for-sale securities |  | 853,946 | [1] | 952,186 |
Financial instruments sold, but not yet purchased, at fair value |  | 164,838 |  | 156,628 |
Agency Mortgage-Backed Securities [Member] | Commercial [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Available-for-sale securities |  | 69,852 | [1] | 73,985 |
Agency Mortgage-Backed Securities [Member] | Non-Agency [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Available-for-sale securities |  | 504 | [1] | 568 |
Sovereign Debt [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 1,279,636 |  |  |
Financial instruments sold, but not yet purchased, at fair value |  |  |  | 2,770 |
Other [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 51,771 | [6] | 41,910 | [7]
Financial instruments sold, but not yet purchased, at fair value | [8] | 4,207 |  |  |
Level 1 [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 133,240 |  | 84,450 |
Investments |  | 13,857 |  | 24,110 |
Total Assets |  | 147,097 |  | 108,560 |
Financial instruments sold, but not yet purchased, at fair value |  | 504,870 |  | 405,505 |
Total, Liabilities |  | 504,870 |  | 405,505 |
Level 1 [Member] | U.S. Government Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 60,821 |  | 10,774 |
Financial instruments sold, but not yet purchased, at fair value |  | 481,889 |  | 377,023 |
Level 1 [Member] | Corporate Fixed Income Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 1,529 |  | 183 |
Financial instruments sold, but not yet purchased, at fair value |  | 496 |  |  |
Level 1 [Member] | Corporate Equity Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 70,890 |  | 73,493 |
Investments |  | 13,730 |  | 13,893 |
Financial instruments sold, but not yet purchased, at fair value |  | 22,485 |  | 28,482 |
Level 1 [Member] | Auction Rate Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments |  |  |  | 0 |
Level 1 [Member] | Other Investment [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments |  |  |  | 10,217 |
Level 1 [Member] | Other [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments |  | 127 |  |  |
Level 2 [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 1,057,007 |  | 980,766 |
Available-for-sale securities |  | 1,926,144 |  | 2,113,893 |
Investments |  | 15,516 |  | 16,013 |
Derivative contracts, Assets |  | 74,646 | [5] | 52,129 | [2]
Total Assets |  | 3,073,313 |  | 3,162,801 |
Financial instruments sold, but not yet purchased, at fair value |  | 436,545 |  | 350,645 |
Derivative contracts, Liabilities |  | 74,658 | [3] | 52,147 | [4]
Total, Liabilities |  | 511,203 |  | 402,792 |
Level 2 [Member] | U.S. Government Agency Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 210,855 |  | 143,793 |
Available-for-sale securities |  | 2,922 |  | 1,808 |
Financial instruments sold, but not yet purchased, at fair value |  | 69,181 |  | 37,395 |
Level 2 [Member] | Asset-Backed Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 19,574 |  | 67,381 |
Available-for-sale securities |  |  |  | 291,054 |
Level 2 [Member] | Corporate Fixed Income Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 257,188 |  | 255,816 |
Available-for-sale securities |  | 730,874 |  | 791,893 |
Financial instruments sold, but not yet purchased, at fair value |  | 198,319 |  | 153,852 |
Level 2 [Member] | Corporate Equity Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 1,147 |  | 1,338 |
Investments |  | 1,661 |  | 1,661 |
Level 2 [Member] | State And Municipal Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 202,737 |  | 162,335 |
Available-for-sale securities |  | 2,366 |  | 2,399 |
Level 2 [Member] | Other Investment [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments |  |  |  | 0 |
Level 2 [Member] | Agency Mortgage-Backed Securities [Member] | Agency Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 348,695 |  | 335,050 |
Available-for-sale securities |  | 853,946 |  | 952,186 |
Financial instruments sold, but not yet purchased, at fair value |  | 164,838 |  | 156,628 |
Level 2 [Member] | Agency Mortgage-Backed Securities [Member] | Commercial [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Available-for-sale securities |  | 69,852 |  | 73,985 |
Level 2 [Member] | Agency Mortgage-Backed Securities [Member] | Non-Agency [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Available-for-sale securities |  | 504 |  | 568 |
Level 2 [Member] | Sovereign Debt [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments sold, but not yet purchased, at fair value |  |  |  | 2,770 |
Level 2 [Member] | Other [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 16,811 | [6] | 15,053 | [7]
Investments |  | 13,855 |  | 14,352 |
Financial instruments sold, but not yet purchased, at fair value | [8] | 4,207 |  |  |
Level 3 [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 89,389 |  | 91,788 |
Investments |  | 60,346 |  | 54,623 |
Total Assets |  | 149,735 |  | 146,411 |
Level 3 [Member] | Asset-Backed Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 53,416 |  | 64,706 |
Level 3 [Member] | Corporate Fixed Income Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 0 |  |  |
Level 3 [Member] | Corporate Equity Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | 1,013 |  | 225 |
Investments |  | 11,878 |  | 5,754 |
Level 3 [Member] | Auction Rate Securities [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments |  | 13,743 |  | 13,032 |
Level 3 [Member] | Other Investment [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Investments |  | 34,725 |  |  |
Level 3 [Member] | Other [Member] |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |
Financial instruments owned |  | $ 34,960 | [6] | 26,857 | [7]
Investments |  |  |  | $ 35,837 |
[1] | Due to the immaterial amount of income recognized on tax-exempt securities, yields were not calculated on a tax-equivalent basis.
[2] | Included in other assets in the consolidated statements of financial condition.
[3] | Included in accounts payable and accrued expenses in the consolidated statements of financial condition.
[4] | Included in accounts payable and accrued expenses in the consolidated statements of financial condition.
[5] | Included in other assets in the consolidated statements of financial condition.
[6] | Includes loans, non-agency mortgage-backed securities, and sovereign debt.
[7] | Includes loans, non-agency mortgage-backed securities, and sovereign debt.
[8] | Includes sovereign debt and state and municipal securities.

X
- Definition Cash equivalents measured at net asset value. + References No definition available. + Details
Name: | sf_CashEquivalentsMeasuredAtNetAssetValue
Namespace Prefix: | sf_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other 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 assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
Name: | us-gaap_DerivativeAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of obligations incurred from short sales. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 940 -SubTopic 320 -Section 35 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35711043&loc=d3e42429-110968 + Details
Name: | us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 + Details
Name: | us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 + Details
Name: | us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value of obligations not classified as financial liabilities. Includes, but is not limited to, accounts payable and accrued liabilities, commitments, obligations, and other liabilities. + References No definition available. + Details
Name: | us-gaap_NonfinancialLiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.4) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 + Details
Name: | us-gaap_TradingSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_SecurityOwnedAndSoldNotYetPurchasedAtFairValueAxis=us-gaap_USGovernmentDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_FixedIncomeSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=sf_CorporateEquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_AuctionRateSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=sf_OtherInvestmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=sf_InvestmentsInFundsAndPartnershipsMeasuredAtNetAssetValueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_AgencySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=sf_NonAgencyMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_UnderlyingAssetClassAxis=us-gaap_SovereignDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_UnderlyingAssetClassAxis=sf_OtherLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |