Number of Properties Transferred from Held for Sale to Held for Use

No definition available.

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- Definition

Number of Real Estate Properties Transferred to Held for Sale

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No definition available.

+ Details

Name:	star_NumberofRealEstatePropertiesTransferredtoHeldforSale
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Data Type:	xbrli:integerItemType
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- Definition

Property Transferred to Held for Sale, Aggregate, Carrying Value

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No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

Carrying amount as of the balance sheet date of investments in land and buildings held for sale, including real estate considered to be inventory of the entity.

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No definition available.

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Data Type:	xbrli:monetaryItemType
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- 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.

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No definition available.

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- Details

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Name:	us-gaap_RealEstatePropertiesAxis=star_ResidentialOperatingPropertiesMember
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Data Type:	na
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- Details

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Real Estate (Real Estate Available and Held for Sale) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($) property	Jun. 30, 2015 USD ($) property	Dec. 31, 2015 USD ($)
Real Estate Properties [Line Items]
Real estate available and held for sale	$ 126,070		$ 137,274
Net Lease
Real Estate Properties [Line Items]
Real estate available and held for sale	$ 0		0
Number of Real Estate Properties Transferred to Held for Sale \| property	1
Commercial Operating Properties
Real Estate Properties [Line Items]
Property transferred to held for sale, carrying value		$ 2,900
Number of Properties Transferred from Held for Sale to Held for Use \| property		1
Residential Operating Properties
Real Estate Properties [Line Items]
Real estate available and held for sale	$ 110,000		$ 137,300
Executed Contract with Third Party \| Net Lease
Real Estate Properties [Line Items]
Property transferred to held for sale, carrying value	$ 700	$ 8,200
Executed Contract with Third Party \| Commercial Operating Properties
Real Estate Properties [Line Items]
Number of Real Estate Properties Transferred to Held for Sale \| property	1
Property transferred to held for sale, carrying value	$ 16,100