Aggregate limited partnership units issued for acquisition purposes

No definition available.

Name:	ck0001412502_AggregateUnitsOfLimitedPartnershipIssuedForAcquisitionUnits
Namespace Prefix:	ck0001412502_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate value of limited partnership units issued for acquisition

+ References

No definition available.

+ Details

Name:	ck0001412502_AggregateUnitsOfLimitedPartnershipIssuedForAcquisitionValue
Namespace Prefix:	ck0001412502_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The purchase price of the acquisition, net of adjustments, if any, for properties in which the percentage acquired was less than one hundred percent.

+ References

No definition available.

+ Details

Name:	ck0001412502_BusinessAcquisitionProrataAcquisitionPrice
Namespace Prefix:	ck0001412502_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount per share or per unit of equity securities issued. Represents the first price.

+ References

No definition available.

+ Details

Name:	ck0001412502_SharesIssuedPricePerShareOne
Namespace Prefix:	ck0001412502_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Units In Property Acquired

+ References

No definition available.

+ Details

Name:	ck0001412502_UnitsInPropertyAcquired
Namespace Prefix:	ck0001412502_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- 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

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

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477

+ Details

Name:	us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585

+ Details

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

- Details

Name:	ck0001412502_RealEstatePropertyAcquisitionsAxis=ck0001412502_SargentApartmentsFargoNDMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ck0001412502_RealEstatePropertyAcquisitionsAxis=ck0001412502_ArrowheadGrandForksNDMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ck0001412502_RealEstatePropertyAcquisitionsAxis=ck0001412502_WestOakFargoNDMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ck0001412502_RealEstatePropertyAcquisitionsAxis=ck0001412502_CarrFargoNDMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Business Combinations and Acquisitions - Purchases, Prior Year (Details) $ / shares in Units, $ in Thousands				3 Months Ended
	Jan. 17, 2017 USD ($) item	Jan. 11, 2017 USD ($) item	Jan. 10, 2017 USD ($) item	Mar. 31, 2018 USD ($) $ / shares shares	Mar. 31, 2017 USD ($) $ / shares shares
BUSINESS COMBINATIONS AND ACQUISITIONS
Acquisition price					$ 8,809
Prorata Acquisition Price					$ 8,809
Aggregate number of limited partnership units issued for acquisition \| shares				84,000	423,000
Price per limited partnership unit issued for acquisition, price one \| $ / shares				$ 18.50	$ 16.00
Aggregate value of limited partnership units issued for acquisition				$ 1,546	$ 6,760
Consideration in cash to pay for acquisitions					$ 2,049
Sargent Apartments, Fargo ND
BUSINESS COMBINATIONS AND ACQUISITIONS
Units acquired \| item			36
Acquisition price			$ 1,710
Prorata Acquisition Price			$ 1,710
Arrowhead, Grand Forks, ND
BUSINESS COMBINATIONS AND ACQUISITIONS
Units acquired \| item		82
Acquisition price		$ 5,494
Prorata Acquisition Price		$ 5,494
West Oak Apartments, Fargo, ND
BUSINESS COMBINATIONS AND ACQUISITIONS
Units acquired \| item	18
Acquisition price	$ 777
Prorata Acquisition Price	$ 777
Carr, Fargo, ND
BUSINESS COMBINATIONS AND ACQUISITIONS
Units acquired \| item	18
Acquisition price	$ 828
Prorata Acquisition Price	$ 828