Summary of Significant Accounting Policies - VIE & Fair Value (Details)	Mar. 31, 2016
Variable Interest Entities
REO assets as a percent of consolidated VIE assets	4.00%
Loans as a percent of consolidated VIE assets	96.00%

Represents REO as a percentage of consolidated VIE assets.

No definition available.

Name:	stwd_ReoAssetsAsPercentOfConsolidatedVieAssets
Namespace Prefix:	stwd_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant