XML 54 R44.htm IDEA: XBRL DOCUMENT v3.19.1

Business and Organization - Narrative (Details) $ in Billions	Mar. 31, 2019 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Investment across a range of real estate sectors over the past two decades (more than)	$ 40

X

- Definition

Real Estate Investment

+ References

No definition available.

+ Details

Name:	star_RealEstateInvestment
Namespace Prefix:	star_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- References

No definition available.

+ Details

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