Debt Instrument, Basis Spread On Variable Rate, Decrease

No definition available.

Name:	stwd_DebtInstrumentBasisSpreadOnVariableRateDecrease
Namespace Prefix:	stwd_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance purchased by third part investors.

+ References

No definition available.

+ Details

Name:	stwd_DebtInstrumentFaceAmountPurchasedByThirdPartyInvestors
Namespace Prefix:	stwd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the minimum interest rate applicable to various debt instruments.

+ References

No definition available.

+ Details

Name:	stwd_DebtInstrumentFloorInterestRate
Namespace Prefix:	stwd_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of Credit Facility, Additional Borrowing Capacity

+ References

No definition available.

+ Details

Name:	stwd_LineOfCreditFacilityAdditionalBorrowingCapacity
Namespace Prefix:	stwd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line Of Credit Facility, Extension Term

+ References

No definition available.

+ Details

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

- Definition

Line Of Credit Facility, Number Of Extension Options

+ References

No definition available.

+ Details

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

- Definition

Number Of Hotels

+ References

No definition available.

+ Details

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

- Definition

The cash outflow associated with the purchase of additional interest in collateralized loan obligations during the period.

+ References

No definition available.

+ Details

Name:	stwd_PaymentsToAcquireAdditionalInterestInCollateralizedLoanObligations
Namespace Prefix:	stwd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the percentage of repurchase agreements containing margin call provisions for general capital market activity.

+ References

No definition available.

+ Details

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

- Definition

Represents the percentage of repurchase agreements containing margin call provisions that pertain to loans held-for-sale.

+ References

No definition available.

+ Details

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

- Definition

Represents the percentage of repurchase agreements which do not permit valuation adjustments based on capital markets activity. Margin calls on these facilities are limited to collateral-specific credit marks.

+ References

No definition available.

+ Details

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

- Definition

Securitizations Of Loans Held For Sale Face Amount

+ References

No definition available.

+ Details

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

- Definition

Amount of amortization expense attributable to debt issuance costs.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(8))
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1F
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495355-112611

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28555-108399

+ Details

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

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=123466204&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 4: 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(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69C
-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69B
-URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612

+ Details

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

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1D
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28555-108399

+ Details

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

- Definition

Cap rate on an interest rate derivative such as an interest rate cap or collar. If market rates exceed the cap rate, a payment or receipt is triggered on the contract.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeCapInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

+ Details

Name:	us-gaap_PaymentsOfDebtIssuanceCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Value of the difference between preference in liquidation and the par or stated values of the preferred shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(d))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=123467817&loc=SL123496158-112644

+ Details

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

- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585

+ Details

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

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount at risk under repurchase agreements is defined as the excess of carrying amount (or market value, if higher than the carrying amount or if there is no carrying amount) of the securities or other assets sold under agreement to repurchase, including accrued interest plus any cash or other assets on deposit to secure the repurchase obligation, over the amount of the repurchase liability (adjusted for accrued interest).

+ References

+ Details

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

- Definition

Weighted average maturity (weighted by amount of the agreement) of repurchase agreements with the counterparty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_RepurchaseAgreementCounterpartyWeightedAverageMaturityOfAgreements1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_CounterpartyNameAxis=stwd_JPMorganChaseBankNAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=stwd_MorganStanleyBankNAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=stwd_RepurchaseAgreementsDebtObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=stwd_WoodstarPortfolioMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=stwd_WoodstarIPortfolioMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=stwd_WoodstarTwoPortfolioMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=stwd_TermLoanFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_CollateralizedLoanObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=stwd_CollateralizedLoanObligationsSTWD2021FL2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=stwd_CollateralizedLoanObligationsSTWD2019FL1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=stwd_CollateralizedLoanObligationsSTWD2021SIF1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Secured Borrowings - Narrative (Details) $ in Thousands	1 Months Ended		12 Months Ended
Secured Borrowings - Narrative (Details) $ in Thousands	Sep. 30, 2021 USD ($)	Jul. 31, 2021 USD ($) hotel	Dec. 31, 2021 USD ($) extension	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	May 31, 2021 USD ($)	Apr. 30, 2021 USD ($)	Aug. 31, 2019 USD ($)
Secured Borrowings
Payment of debt			$ 11,929,179	$ 6,137,778	$ 8,671,085
Principal amount of notes purchased by third-party investors		$ 210,100
JPMorgan Chase Bank N.A.
Secured Borrowings
Amount at risk			$ 667,200
Weighted average extended maturities			3 years 8 months 12 days
Morgan Stanley Bank, N.A.
Secured Borrowings
Amount at risk			$ 660,400
Weighted average extended maturities			3 years 9 months 18 days
Revolving credit facility
Secured Borrowings
Maximum borrowing capacity	$ 150,000		$ 150,000
Increase in borrowing capacity	$ 30,000
RMBS
Secured Borrowings
Securitizations of loans		$ 230,000
Number of hotels \| hotel		41
LIBOR \| Revolving credit facility
Secured Borrowings
Decrease in basis spread	0.50%
SOFR \| Revolving credit facility
Secured Borrowings
Pricing margin	2.50%
Secured Borrowings
Secured Borrowings
Amortization of deferred financing costs			35,600	36,400	34,300
Long term debt, gross			$ 12,654,420	10,233,589
Repurchase Agreements
Secured Borrowings
Percentage of repurchase agreements for which margin calls are limited to collateral specific credit marks			66.00%
Percentage of repurchase agreements containing margin call provisions for general capital market activity			34.00%
Percentage of repurchase agreements containing margin call provisions that pertain to loans held-for-sale			7.00%
Woodstar Portfolio
Secured Borrowings
Proceeds from debt			$ 462,900
Woodstar I Portfolio
Secured Borrowings
Payment of debt			222,000
Maximum borrowing capacity			$ 380,000
Maturity period			2 years
Number of extension options \| extension			3
Extension term			1 year
Interest rate cap strike percentage			1.00%
Woodstar I Portfolio \| LIBOR
Secured Borrowings
Pricing margin			2.11%
Woodstar II Portfolio
Secured Borrowings
Maximum borrowing capacity			$ 82,900
Maturity period			7 years
Woodstar II Portfolio \| LIBOR
Secured Borrowings
Pricing margin			4.36%
Term Loan Facility
Secured Borrowings
Maximum borrowing capacity			$ 788,800
Floor interest rate (as a percent)	0.75%		0.75%
Increase in borrowing capacity	$ 150,000
Term Loan Facility \| LIBOR
Secured Borrowings
Pricing margin	3.25%
Decrease in basis spread	0.25%
CLOs and SASB
Secured Borrowings
Amortization of deferred financing costs			$ 5,700	2,500	900
Incurred debt issuance costs			26,900
Deferred financing costs, net of amortization			17,700	5,800
STWD 2021-FL2
Secured Borrowings
Principal amount of notes purchased by third-party investors						$ 1,100,000
Amount issued						1,300,000
Long term debt, gross						70,100
Liquidation preference						$ 127,500
Additional contribution to CLO			58,600
STWD 2019-FL1
Secured Borrowings
Principal amount of notes purchased by third-party investors								$ 936,400
Amount issued								1,100,000
Long term debt, gross								86,600
Liquidation preference								$ 77,000
Additional contribution to CLO			261,900	$ 134,700	$ 88,100
STWD 2021-SIF1
Secured Borrowings
Principal amount of notes purchased by third-party investors							$ 410,000
Amount issued							500,000
Liquidation preference							$ 90,000
Additional contribution to CLO			$ 45,900