Basis of Presentation and Principles of Consolidation (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013 investments
Consolidated VIEs
Total revenues and total expenses related to consolidated VIEs
Number of variable interest entities (in investments)	5
Carrying amount, assets	$ 213.8
Carrying amount, liabilities	27.6
Variable interest entity unfunded commitment	44.7
Unconsolidated VIEs
Total revenues and total expenses related to consolidated VIEs
Number of variable interest entities (in investments)	29
Carrying value of the investments	163.7
Variable interest entity unfunded commitment	$ 8.1

Represents the number of variable interest entities of the entity.

No definition available.

Name:	sfi_VariableInterestEntityNumber
Namespace Prefix:	sfi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of unfunded commitments that the entity has to the Variable Interest Entity.

+ References

No definition available.

+ Details

Name:	sfi_VariableInterestEntityUnfundedCommitment
Namespace Prefix:	sfi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (bb)

-URI http://asc.fasb.org/extlink&oid=7880789&loc=d3e5710-111685

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The carrying amount of the consolidated Variable Interest Entity's liabilities included in the reporting entity's statement of financial position.

+ References

+ Details

Name:	us-gaap_VariableInterestEntityConsolidatedCarryingAmountLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_VariableInterestEntityMeasureOfActivityAbstract
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Data Type:	xbrli:stringItemType
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Period Type:	duration

- Definition

Net carrying amount of the assets and liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), when the reporting entity is not the VIE's primary beneficiary.

+ References

No definition available.

+ Details

Name:	us-gaap_VariableInterestEntityNonconsolidatedCarryingAmountAssetsAndLiabilitiesNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant