Summary of Significant Accounting Policies (Details)	Sep. 30, 2015
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