Loans Receivable and Other Lending Investments, net (Troubled Debt Restructurings) (Details)	Jun. 30, 2015 USD ($)
Receivables [Abstract]
Unfunded commitments, troubled debt restructurings	$ 0

Represents the amount of the outstanding unfunded commitment related to financing receivables that has been modified by troubled debt restructurings.

No definition available.

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