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Represents the percentage of the reference rate for the variable rate on available-for-sale securities as of the balance sheet date.

No definition available.

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The percentage points added to the reference rate to compute the variable rate on available-for-sale securities.

No definition available.

Name:	stwd_AvailableForSaleSecuritiesWeightedAverageBasisSpreadOnVariableRate
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Data Type:	num:percentItemType
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This relates to loans with deteriorating of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

No definition available.

Name:	stwd_CertainLoansAcquiredAccretableYield
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Represents the discount amount of all uncollected contractual principal past due and scheduled for the future, adjusted for the timing of prepayments, if considered, less any reduction by the investor at the acquisition date. This relates to loans accounted for as debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition that the investor will be unable to collect all contractually required payments receivable.

No definition available.

Name:	stwd_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAcquiredDuringPeriodContractuallyRequiredPaymentsReceivableAtAcquisitionDiscount
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Represents the total undiscounted amount of all uncollected contractual principal and contractual interest payments both past due and scheduled for the future, adjusted for the timing of prepayments, if considered, less any reduction by the investor at the acquisition date. This relates to loans accounted for as debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition that the investor will be unable to collect all contractually required payments receivable.

No definition available.

Name:	stwd_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesAcquiredDuringPeriodContractuallyRequiredPaymentsReceivableAtAcquisitionPrincipalAmount
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The amount of the loans contractually required payments receivable in excess of the amount of its cash flows expected to be collected for loans accounted for as debt securities, with the evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition that the investor will be unable to collect all contractually required payments receivable.

No definition available.

Name:	stwd_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesNonaccretableYield
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- References

No definition available.

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The amount of write-down of principal of a loan during the period resulting in a reduction in the excess amount of the loan's contractually required payments receivable in excess of the amount of its cash flows expected to be collected for loans. This relates to loans not accounted for as a debt security, with the evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition that the investor will be unable to collect all contractually required payments receivable.

No definition available.

Name:	stwd_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesNonaccretableYieldPrincipalWrittenDown
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Change in the estimate of cash flows expected to be collected, which results in a decrease in nonaccretable yield. This relates to a loan accounted for as an available-for-sale debt security, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

No definition available.

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Represents the balance of mortgage backed securities with deteriorated credit quality.

No definition available.

Name:	stwd_CertainLoansAcquiredWithDeterioratedCredit
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Represents the amount of investment securities bearing variable interest rates.

No definition available.

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Represents the percentage of investment securities bearing variable interest rates.

No definition available.

Name:	stwd_InvestmentSecuritiesVariableRatePercentage
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Balance Type:	na
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Represents the weighted average coupon interest rate on investment securities.

No definition available.

Name:	stwd_InvestmentSecuritiesWeightedAverageInterestRateStatedPercentage
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Represents the weighted average life of investment securities.

No definition available.

Name:	stwd_InvestmentSecuritiesWeightedAverageLife
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Data Type:	xbrli:durationItemType
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Period Type:	duration

Cash inflow from proceeds from principal collections on investment securities.

No definition available.

Name:	stwd_ProceedsFromPrincipalCollectionsOnInvestmentSecurities
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Period Type:	duration

Total debt and equity financial instruments purchased during the period.

No definition available.

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Total debt and equity financial instruments sold during the period.

No definition available.

Name:	stwd_SaleOfMarketableSecurities
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Accumulated other comprehensive loss related to portion of other than temporary impairment (OTTI) due to factors other than credit losses on debt securities categorized as available-for-sale that an entity does not intend to sell and which it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis of the debt security. The amount represented by this item is net of tax, as applicable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aaa)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 220
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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount before tax of unrealized gain (loss) in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

No definition available.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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The aggregate excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan for loans accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 310
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-Section 50
-Paragraph 2
-Subparagraph (a)(2)
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Current period recognition due to accretion of the excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan for loans accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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Change in the estimate of cash flows expected to be collected, after acquisition of a loan, which results in an increase in accretable yield (for example, if actual cash flows are significantly greater than previously expected). This relates to loans accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and other-than-temporary impairments), for loans accounted for as debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
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The amount of the loan's contractually required payments receivable in excess of the amount of its cash flows expected to be collected. This relates to loans with deteriorating of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

No definition available.

Name:	us-gaap_CertainLoansAcquiredInTransferNonaccretableDifference
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Total debt and equity financial instruments including: (1) securities held-to-maturity, (2) trading securities, and (3) securities available-for-sale.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-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=6876686&loc=d3e534808-122878

Name:	us-gaap_MarketableSecurities
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Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as available-for-sale.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Mortgage-Backed Securities
-URI http://asc.fasb.org/extlink&oid=6517959

Name:	us-gaap_MortgageBackedSecuritiesAvailableForSaleFairValueDisclosure
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The cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (a component of shareholders' equity).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27340-111563

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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.

No definition available.

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Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
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