Development in Process, Expected Costs

No definition available.

Name:	inn_DevelopmentinProcessExpectedCosts
Namespace Prefix:	inn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Development in Process, Expected Costs, Incurred to Date

+ References

No definition available.

+ Details

Name:	inn_DevelopmentinProcessExpectedCostsIncurredtoDate
Namespace Prefix:	inn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Financing Receivable, Portion Applied Toward Sale of Hotel Properties Transaction by Borrower

+ References

No definition available.

+ Details

Name:	inn_FinancingReceivablePortionAppliedTowardSaleofHotelPropertiesTransactionbyBorrower
Namespace Prefix:	inn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the number of agreements pertaining to the transaction.

+ References

No definition available.

+ Details

Name:	inn_NumberOfAgreements
Namespace Prefix:	inn_
Data Type:	xbrli:integerItemType
Balance Type:	na
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

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

- Definition

Amount of gain on the sale of property that does not qualify for gain recognition as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredGainOnSaleOfProperty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The current amount of expenditures for a real estate project that has not yet been completed.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.10)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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

- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

No definition available.

+ Details

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

- Definition

Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2443-110228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84176398&loc=d3e2941-110230

+ Details

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

- Definition

A deposit made by a purchaser of real estate to evidence good faith. It is customary for a buyer to give the seller earnest money at the time a sales contract is signed. The earnest money generally is credited to the down payment at closing, which is applied at closing as a component of payment against the purchase price.

+ References

No definition available.

+ Details

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

- Definition

Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(3))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Definition

The number of real estate properties owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfRealEstateProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of units in a real estate property owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfUnitsInRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow from the repayment of a long-term debt instrument issued, secured by a first mortgage deed of trust, containing a pledge of real property. The lender has the highest claim on the property in case of default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

+ Details

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

- Details

Name:	us-gaap_MajorPropertyClassAxis=us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=inn_HyattHouseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=inn_OrlandoFLMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=inn_HolidayInnExpressAndSuitesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=inn_SandyUTMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=inn_HamptonInnMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=inn_ProvoUtahMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=inn_HolidayInnMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=inn_DuluthGeorgiaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=inn_HiltonGardenInnMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=inn_PortfolioOfHotelsToHITMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=inn_PortfolioOfHotelsToHITTrancheTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=inn_PortfolioOfHotelsToHITTrancheThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=inn_HyattPlaceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=inn_AtlantaGAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

INVESTMENT IN HOTEL PROPERTIES, NET - Narrative (Details) $ in Thousands		3 Months Ended	34 Months Ended
	Mar. 30, 2017 USD ($)	Mar. 31, 2018 USD ($) hotel Room	Mar. 31, 2018 USD ($) hotel Room	Mar. 01, 2018 USD ($) contract	Feb. 22, 2018 USD ($) contract	Dec. 31, 2017 USD ($)	Apr. 30, 2017 USD ($) hotel Room	Feb. 29, 2016 USD ($) hotel	Jun. 08, 2015 USD ($) hotel
Business Acquisition [Line Items]
Investment in hotel properties under development		$ 28,267	$ 28,267			$ 23,793
Number of hotels \| hotel		83	83
Assets held-for-sale
Business Acquisition [Line Items]
Number of hotels \| hotel		4	4
Hyatt House \| Orlando, FL
Business Acquisition [Line Items]
Number of guestrooms \| Room		168	168
Development in process, expected costs		$ 32,000	$ 32,000
Development in process, expected costs incurred to date		25,500	25,500
Investment in hotel properties under development		2,800	2,800
Holiday Inn Express & Suites \| Sandy, UT
Business Acquisition [Line Items]
Aggregate sales price					$ 9,000
Hampton Inn \| Provo, Utah
Business Acquisition [Line Items]
Aggregate sales price					$ 10,000
Holiday Inn \| Duluth, GA
Business Acquisition [Line Items]
Aggregate sales price				$ 8,300
Hilton Garden Inn \| Duluth, GA
Business Acquisition [Line Items]
Aggregate sales price				$ 16,000
Disposed of by Sale
Business Acquisition [Line Items]
Number of guestrooms \| Room							2,448
Number of sales agreements \| contract				2	2
Aggregate sales price		$ 325,100	$ 325,100				$ 325,100
Number of hotels \| hotel		23	23				23
Disposed of by Sale \| Portfolio of Hotels to HIT
Business Acquisition [Line Items]
Note receivable									$ 27,500
Net gain on sale of properties			$ 15,000
Disposed of by Sale \| Portfolio of Hotels to HIT, Tranche Two
Business Acquisition [Line Items]
Aggregate sales price								$ 108,300	108,300
Receivable portion applied toward sale of hotel properties transaction by borrower									$ 20,000
Number of hotels \| hotel								6	6
Deferred gain on sale of property								$ 20,000
Disposed of by Sale \| Portfolio of Hotels to HIT, Tranche Three
Business Acquisition [Line Items]
Aggregate sales price							$ 66,800
Number of hotels \| hotel							7
Earnest money deposits									$ 7,500
Disposed of by Sale \| Hyatt Place \| Atlanta, GA
Business Acquisition [Line Items]
Aggregate sales price	$ 14,500
Net gain on sale of properties		$ 4,800
Repayment of mortgage loan	$ 6,500