Represents loans as a percentage of consolidated VIE assets.

No definition available.

Name:	stwd_LoansAsPercentOfConsolidatedVieAssets
Namespace Prefix:	stwd_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Noncontrolling Interest, Sale Of Investment Interest, Percentage

+ References

No definition available.

+ Details

Name:	stwd_NoncontrollingInterestSaleOfInvestmentInterestPercentage
Namespace Prefix:	stwd_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of properties in the portfolio investment.

+ References

No definition available.

+ Details

Name:	stwd_NumberOfPropertiesInPortfolioInvestment
Namespace Prefix:	stwd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of units in the portfolio investment.

+ References

No definition available.

+ Details

Name:	stwd_NumberOfUnitsInPortfolioInvestment
Namespace Prefix:	stwd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the permitted reinvestment amount in the Variable Interest Entities (VIE) in which the entity has invested and the investment is static.

+ References

No definition available.

+ Details

Name:	stwd_PermittedReinvestmentUnderStaticInvestmentInVariableInterestEntity
Namespace Prefix:	stwd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents REO as a percentage of consolidated VIE assets.

+ References

No definition available.

+ Details

Name:	stwd_ReoAssetsAsPercentOfConsolidatedVieAssets
Namespace Prefix:	stwd_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Subscription Fund, Term

+ References

No definition available.

+ Details

Name:	stwd_SubscriptionFundTerm
Namespace Prefix:	stwd_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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

- Definition

Amount of cash inflow from a noncontrolling interest. Includes, but is not limited to, purchase of additional shares or other increase in noncontrolling interest ownership.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromMinorityShareholders
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=stwd_WoodstarFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Summary of Significant Accounting Policies (Details)			3 Months Ended
Summary of Significant Accounting Policies (Details)	Nov. 06, 2021 USD ($)	Nov. 05, 2021 USD ($) unit property	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
REO assets as a percent of consolidated VIE assets			1.00%
Loans as a percent of consolidated VIE assets			99.00%
Permitted reinvestment under static investment in VIEs			$ 0
Number of properties in portfolio investment \| property		59
Number of units in portfolio investment \| unit		15,057
Contributions from non-controlling interests			$ 0	$ 4,690,000
Woodstar Fund
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Percentage of interest sold		20.60%
Contributions from non-controlling interests	$ 214,200,000	$ 216,000,000
Fund term		8 years