Debt Instrument, Amortization Payment Term

No definition available.

Name:	inn_DebtInstrumentAmortizationPaymentTerm
Namespace Prefix:	inn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Principal Amount Defeased

+ References

No definition available.

+ Details

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

- Definition

Debt Transaction Costs

+ References

No definition available.

+ Details

Name:	inn_DebtTransactionCosts
Namespace Prefix:	inn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the number of real estate properties owned as of the balance sheet date encumbered by mortgages.

+ References

No definition available.

+ Details

Name:	inn_MortgageLoansOnRealEstateNumberOfRealEstatePropertiesEncumbered
Namespace Prefix:	inn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number Of Promissory Notes

+ References

No definition available.

+ Details

Name:	inn_NumberOfPromissoryNotes
Namespace Prefix:	inn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of Unencumbered Hotel Properties

+ References

No definition available.

+ Details

Name:	inn_NumberOfUnencumberedHotelProperties
Namespace Prefix:	inn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of mortgage loans within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Footnote 3
-Subsection 29

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Footnote 3))
-URI http://asc.fasb.org/extlink&oid=120402547&loc=d3e617274-123014

+ Details

Name:	srt_MortgageLoansOnRealEstateNumberOfLoans
Namespace Prefix:	srt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

The cash inflow from amounts received from issuance of long-term debt that is wholly or partially secured by collateral. Excludes proceeds from tax exempt secured debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfSecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_A75MillionTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_A125MillionRevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_SeniorCreditFacilitySixHundredMillionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_RevolvingCreditFacilityFourHundredMillionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_TermLoanTwoHundredMillionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_JointVentureCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_KeybankNationalAssociationTermLoanDueNovember252022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_KeybankNationalAssociationTermLoanDueFebruary142025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_A2017TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_MortgagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_MortgageLoanWithKeyBankNationalAssociation4.46PercentDue1February2023Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_MortgageLoanWithKeyBankNationalAssociation4.52PercentDue1April2023Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_MortgageLoanWithKeyBankNationalAssociation4.3PercentDue1April2023Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_MortgageLoanWithKeyBankNationalAssociation4.95PercentDue1August2023Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_MortgageLoanWithMetaBankDueJuly12027Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_MortgageLoanWithBankOfCascadesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_MortgageLoanWithBankOfCascadesDueDecember192024NoteAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=inn_MortgageLoanWithBankOfCascadesDueDecember192024NoteBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

DEBT - Summary of outstanding indebtedness (Details)			12 Months Ended
DEBT - Summary of outstanding indebtedness (Details)	Mar. 19, 2019 USD ($)	Dec. 19, 2014 USD ($) contract Instrument	Dec. 31, 2020 USD ($) Property hotel	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jan. 12, 2021 USD ($)	Oct. 08, 2019 USD ($)	Dec. 06, 2018 USD ($)	Sep. 26, 2017 USD ($)	Jul. 22, 2013 USD ($) Property	Mar. 08, 2013 USD ($) Property	Mar. 07, 2013 USD ($) Property	Jan. 25, 2013 USD ($) Property
Debt Instrument [Line Items]
Debt outstanding			$ 1,101,478,000	$ 1,022,726,000
Unamortized debt issuance costs			(6,733,000)	(6,563,000)
Debt, net of issuance costs			1,094,745,000	1,016,163,000
Debt transaction costs			365,000	1,892,000	$ 401,000
$75 Million Term Loan
Debt Instrument [Line Items]
Debt instrument, face amount							$ 75,000,000
Revolving credit facility \| $125 Million Revolver
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity							$ 125,000,000
Unsecured debt \| Senior credit facility $600 Million
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity			600,000,000					$ 600,000,000.0
Debt outstanding			$ 355,000,000	275,000,000
Number of unencumbered hotel properties \| hotel			52
Unsecured debt \| $400 Million Revolver
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity								400,000,000
Unsecured debt \| $400 Million Revolver \| Subsequent events
Debt Instrument [Line Items]
Debt, net of issuance costs						$ 160,000,000.0
Unsecured debt \| $200 Million Term Loan
Debt Instrument [Line Items]
Debt instrument, face amount								$ 200,000,000.0
Stated interest rate			2.35%
Debt outstanding			$ 200,000,000	200,000,000
Unsecured debt \| Joint Venture Credit Facility
Debt Instrument [Line Items]
Debt outstanding			$ 142,500,000	140,000,000
Unsecured debt \| $75 Million Term Loan
Debt Instrument [Line Items]
Stated interest rate			2.35%
Debt outstanding			$ 75,000,000	75,000,000
Unsecured debt \| Keybank National Association Term Loan due November 25, 2022
Debt Instrument [Line Items]
Debt outstanding			$ 225,000,000	225,000,000
Unsecured debt \| Keybank National Association Term Loan due February 14, 2025
Debt Instrument [Line Items]
Stated interest rate			2.15%
Debt outstanding			$ 225,000,000	225,000,000
Unsecured debt \| 2017 Term Loan
Debt Instrument [Line Items]
Debt instrument, face amount									$ 225,000,000.0
Unsecured debt \| 2017 Term Loan \| Subsequent events
Debt Instrument [Line Items]
Debt, net of issuance costs						$ 98,500,000
Unsecured debt \| Revolving credit facility \| $400 Million Revolver
Debt Instrument [Line Items]
Stated interest rate			2.40%
Debt outstanding			$ 155,000,000	75,000,000
Unsecured debt \| Revolving credit facility \| $125 Million Revolver
Debt Instrument [Line Items]
Stated interest rate			2.40%
Debt outstanding			$ 67,500,000	65,000,000
Unsecured debt \| Revolving credit facility \| Keybank National Association Term Loan due November 25, 2022
Debt Instrument [Line Items]
Stated interest rate			2.45%
Mortgage loans
Debt Instrument [Line Items]
Number of Properties Encumbered \| Property			15
Debt outstanding			$ 153,978,000	157,726,000
Mortgage loans \| KeyBank National Association 4.46% Fixed due February 1, 2023
Debt Instrument [Line Items]
Debt instrument, face amount													$ 29,400,000
Stated interest rate			4.46%										4.46%
Amortization Period (Years)			30 years
Number of Properties Encumbered \| Property			3										3
Debt outstanding			$ 19,039,000	19,510,000
Debt principal amount defeased	$ 6,300,000
Debt transaction costs	$ 600,000
Mortgage loans \| KeyBank National Association 4.52% Fixed due April 1, 2023
Debt Instrument [Line Items]
Debt instrument, face amount												$ 22,700,000
Stated interest rate			4.52%									4.52%
Amortization Period (Years)			30 years
Number of Properties Encumbered \| Property			3									3
Debt outstanding			$ 19,520,000	19,992,000
Mortgage loans \| KeyBank National Association 4.30% Fixed due April 1, 2023
Debt Instrument [Line Items]
Debt instrument, face amount											$ 22,000,000.0
Stated interest rate			4.30%								4.30%
Amortization Period (Years)			30 years
Number of Properties Encumbered \| Property			3								3
Debt outstanding			$ 18,852,000	19,323,000
Mortgage loans \| KeyBank National Association 4.95% Fixed due August 1, 2023
Debt Instrument [Line Items]
Debt instrument, face amount										$ 38,700,000
Stated interest rate			4.95%							4.95%
Amortization Period (Years)			30 years
Number of Properties Encumbered \| Property			2							2
Debt outstanding			$ 33,947,000	34,695,000
Mortgage loans \| Meta Bank 4.44% Fixed due July 1, 2027
Debt Instrument [Line Items]
Stated interest rate			4.44%
Amortization Period (Years)			25 years
Number of Properties Encumbered \| Property			3
Debt outstanding			$ 46,172,000	47,226,000
Mortgage loans \| Bank of Cascades loan(s)
Debt Instrument [Line Items]
Amortization Period (Years)		25 years
Loan increase		$ 7,900,000
Number of loans \| contract		2
Number of promissory notes \| Instrument		2
Mortgage loans \| Bank Of Cascades Variable due December 19, 2024, Note A
Debt Instrument [Line Items]
Stated interest rate			2.14%
Amortization Period (Years)			25 years
Number of Properties Encumbered \| Property			1
Debt outstanding			$ 8,224,000	8,490,000
Mortgage loans \| Bank Of Cascades 4.30% Fixed due December 19, 2024, Note B
Debt Instrument [Line Items]
Stated interest rate		4.30%	4.30%
Amortization Period (Years)			25 years
Number of Properties Encumbered \| Property			0
Debt outstanding			$ 8,224,000	$ 8,490,000
LIBOR \| Mortgage loans \| Bank Of Cascades Variable due December 19, 2024, Note A
Debt Instrument [Line Items]
Interest rate margin on variable rate basis		2.00%