Loan Securitization/Sale Activities - Loans (Details) - Commercial Loans - Commercial Loans - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Loan Transfer Activities
Face Amount	$ 268,016	$ 211,700
Proceeds	$ 278,731	$ 218,596

Represents the fair value of loans held-for-sale, sold during the period.

No definition available.

Name:	stwd_LoansHeldForSaleSoldFairValue
Namespace Prefix:	stwd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration