The amount paid on deferred purchase price obligations during the period.

No definition available.

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

- Definition

Purchase price for properties acquired.

+ References

No definition available.

+ Details

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

- Definition

Related Party Transaction, Commitment to Extend Credit, Deferred Purchase Price

+ References

No definition available.

+ Details

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

- Definition

Related Party Transaction, Commitment to Extend Credit, Leasehold Improvement Allowance

+ References

No definition available.

+ Details

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

- Definition

Related Party Transaction, Commitment to Extend Credit, Amount Funded

+ References

No definition available.

+ Details

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

- Definition

Related Party Transaction, Loan, Consideration Received

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=123351718&loc=d3e2443-110228

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount, before valuation allowance, of financing receivable classified as held-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124265262&loc=d3e48678-111004

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Period Type:

Loans Receivable and Other Lending Investments, net (Loan Receivable Held for Sale) (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended	6 Months Ended		7 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Sep. 30, 2021	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Income from sales of real estate			$ 96	$ 492	$ 708
Purchase price for properties acquired			42,000		42,000
Loan receivable held for sale							$ 43,215
Safehold Inc.
Debt Securities, Available-for-sale [Line Items]
Amount of loan funded		$ 16,100
Deferred purchase price		11,900
Leasehold improvement allowance		$ 52,000
Payment of deferred purchase price						$ 6,000
Consideration received	$ 22,100
Income from sales of real estate	$ 0
Loans Receivable Held-for-sale
Debt Securities, Available-for-sale [Line Items]
Loan receivable held for sale			$ 42,000		$ 42,000