Organization and Principal Business (Details) $ in Millions	May 14, 2021 USD ($)
Minimum [Member]
Investment Owned, Balance [Abstract]
Threshold value for small and medium-sized businesses, annual revenues	$ 15
Maximum [Member]
Investment Owned, Balance [Abstract]
Threshold value for small and medium-sized businesses, EBITDA value	$ 50

Maximum value of earnings before interest, taxes, depreciation and amortization ("EBITDA") for small and medium-sized businesses.

No definition available.

Name:	star_ThresholdValueForSmallAndMediumSizedBusinessesEarningsBeforeInterestTaxesDepreciationAndAmortization
Namespace Prefix:	star_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration