Debt Instrument, Amortization Payment Term

No definition available.

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

- Definition

Debt Instrument, Amortization Period After Interest Only Payments Period

+ References

No definition available.

+ Details

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

- Definition

Debt Instrument, Interest Only Payments Term

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
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

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

- 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=6589523&loc=d3e617274-123014

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount of liabilities incurred by the acquirer as part of consideration transferred in a business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109124213&loc=d3e6578-128477

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6405-128476

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=109124213&loc=d3e6613-128477

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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=109500613&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=6879938&loc=d3e572229-122910

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-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=6877327&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=6876686&loc=d3e534808-122878

+ Details

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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
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-SubTopic 30
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-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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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=6877327&loc=d3e13212-122682

+ Details

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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

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Balance Type:	na
Period Type:	duration

- 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=109500613&loc=SL6031897-161870

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-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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Balance Type:	na
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=109223946&loc=d3e3255-108585

+ Details

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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=6877327&loc=d3e13212-122682

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Balance Type:	debit
Period Type:	instant

DEBT - Summary of outstanding indebtedness (Details)				12 Months Ended
DEBT - Summary of outstanding indebtedness (Details)	Dec. 19, 2014 USD ($) contract	May 06, 2014 USD ($)	Jan. 10, 2014 USD ($) Room	Dec. 31, 2018 USD ($) Property	Dec. 06, 2018 USD ($)	Dec. 31, 2017 USD ($) Room	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				$ 965,011,000		$ 873,109,000
Unamortized debt issuance costs				(6,299,000)		(4,873,000)
Debt, net of issuance costs				958,712,000		$ 868,236,000
Number of guestrooms \| Room						2,442
Unsecured debt \| Senior unsecured credit facility $600 Million
Debt Instrument [Line Items]
Debt outstanding				315,000,000		$ 0
Unsecured debt \| $200 Million Term Loan
Debt Instrument [Line Items]
Debt outstanding				$ 200,000,000		0
Stated interest rate				4.10%
Debt instrument, face amount					$ 200,000,000.0
Unsecured debt \| Senior unsecured credit facility $450 Million
Debt Instrument [Line Items]
Debt outstanding				$ 0		165,000,000
Unsecured debt \| $150 Million Term Loan
Debt Instrument [Line Items]
Debt outstanding				0		150,000,000
Debt instrument, face amount						150,000,000.0
Unsecured debt \| KeyBank National Association Term Loan due April 7, 2022
Debt Instrument [Line Items]
Debt outstanding				0		140,000,000
Unsecured debt \| Keybank National Association Term Loan due November 25, 2022
Debt Instrument [Line Items]
Debt outstanding				$ 225,000,000		225,000,000
Stated interest rate				4.10%
Unsecured debt \| Keybank National Association Term Loan due February 14, 2025
Debt Instrument [Line Items]
Debt outstanding				$ 225,000,000		0
Stated interest rate				4.40%
Unsecured debt \| Revolving credit facility
Debt Instrument [Line Items]
Debt outstanding				$ 115,000,000		0
Unsecured debt \| Revolving credit facility \| $400 Million Revolver
Debt Instrument [Line Items]
Stated interest rate				4.15%
Unsecured debt \| Revolving credit facility \| $300 Million Revolver
Debt Instrument [Line Items]
Debt outstanding				$ 0		15,000,000
Mortgage loans
Debt Instrument [Line Items]
Debt outstanding				$ 200,011,000		343,109,000
Number of properties encumbered \| Property				21
Mortgage loans \| Voya (formerly known as ING Life Insurance and Annuity) due March 1, 2019 One
Debt Instrument [Line Items]
Debt outstanding				$ 0		40,015,000
Mortgage loans \| Voya (formerly known as ING Life Insurance and Annuity) due March 1, 2019 Two
Debt Instrument [Line Items]
Debt outstanding				0		35,865,000
Mortgage loans \| Voya (formerly known as ING Life Insurance and Annuity) due March 1, 2019 Three
Debt Instrument [Line Items]
Debt outstanding				0		23,130,000
Mortgage loans \| Voya (formerly known as ING Life Insurance and Annuity) due March 1, 2019 Four
Debt Instrument [Line Items]
Debt outstanding				0		16,431,000
Mortgage loans \| KeyBank National Association 4.46% Fixed due February 1, 2023
Debt Instrument [Line Items]
Debt outstanding				$ 26,357,000		26,928,000
Stated interest rate				4.46%						4.46%
Number of properties encumbered \| Property				4						4
Amortization Period (Years)				30 years
Debt instrument, face amount										$ 29,400,000
Mortgage loans \| KeyBank National Association 4.52% Fixed due April 1, 2023
Debt Instrument [Line Items]
Debt outstanding				$ 20,444,000		20,877,000
Stated interest rate				4.52%
Number of properties encumbered \| Property				3					3
Amortization Period (Years)				30 years
Debt instrument, face amount									$ 22,700,000
Mortgage loans \| KeyBank National Association 4.30% Fixed due April 1, 2023
Debt Instrument [Line Items]
Debt outstanding				$ 19,777,000		20,211,000
Stated interest rate				4.30%				4.30%
Number of properties encumbered \| Property				4				3
Amortization Period (Years)				30 years
Debt instrument, face amount								$ 22,000,000
Mortgage loans \| KeyBank National Association 4.95% Fixed due August 1, 2023
Debt Instrument [Line Items]
Debt outstanding				$ 35,411,000		36,093,000
Stated interest rate				4.95%			4.95%
Number of properties encumbered \| Property				2			2
Amortization Period (Years)				30 years
Debt instrument, face amount							$ 38,700,000
Mortgage loans \| West Alliance Bank due April 1, 2020 one
Debt Instrument [Line Items]
Debt outstanding				$ 0		8,701,000
Amortization Period (Years)				25 years
Mortgage loans \| West Alliance Bank due April 1, 2020 two
Debt Instrument [Line Items]
Debt outstanding				$ 0		4,685,000
Amortization Period (Years)				25 years
Mortgage loans \| Meta Bank 4.44% Fixed due July 1, 2027
Debt Instrument [Line Items]
Debt outstanding				$ 47,640,000		47,640,000
Stated interest rate				4.44%
Number of properties encumbered \| Property				3
Amortization Period (Years)				25 years
Mortgage loans \| Bank of Cascades loan(s)
Debt Instrument [Line Items]
Number of loans \| contract	2
Amortization Period (Years)	25 years
Loan increase	$ 7,900,000
Mortgage loans \| Bank Of Cascades Variable due December 19, 2024, Note A
Debt Instrument [Line Items]
Debt outstanding				$ 8,757,000		9,023,000
Stated interest rate				4.50%
Number of properties encumbered \| Property				1
Amortization Period (Years)				25 years
Mortgage loans \| Bank Of Cascades 4.30% Fixed due December 19, 2024, Note B
Debt Instrument [Line Items]
Debt outstanding				$ 8,757,000		9,023,000
Stated interest rate	4.30%			4.30%
Number of properties encumbered \| Property				0
Amortization Period (Years)				25 years
Mortgage loans \| Compass Bank Variable due May 6, 2020
Debt Instrument [Line Items]
Debt outstanding				$ 22,151,000		22,773,000
Stated interest rate				4.90%
Number of properties encumbered \| Property				3
Amortization Period (Years)		25 years		25 years
Debt instrument, face amount		$ 25,000,000
Mortgage loans \| West Alliance Bank due April 1, 2020, one
Debt Instrument [Line Items]
Debt outstanding				$ 0		5,769,000
Amortization Period (Years)				25 years
Mortgage loans \| West Alliance Bank due April 1, 2020, two
Debt Instrument [Line Items]
Debt outstanding				$ 0		4,926,000
Amortization Period (Years)				25 years
Mortgage loans \| U.S. Bank, NA 6.13% Fixed due November 11, 2021
Debt Instrument [Line Items]
Debt outstanding				$ 10,717,000		$ 11,019,000
Stated interest rate			6.133%	6.13%
Number of properties encumbered \| Property				1
Amortization Period (Years)			25 years	25 years
Secured debt \| Meta Bank 4.44% Fixed due July 1, 2027
Debt Instrument [Line Items]
Stated interest rate				4.44%
Debt interest only payments term				18 months
Loan amortization period after interest only payments period				25 years
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%
LIBOR \| Mortgage loans \| Compass Bank Variable due May 6, 2020
Debt Instrument [Line Items]
Interest rate margin on variable rate basis		2.40%
Hampton Inn \| Santa Barbara (Goleta), CA
Debt Instrument [Line Items]
Number of guestrooms \| Room			98
Hampton Inn \| Santa Barbara (Goleta), CA \| Mortgage loans \| U.S. Bank, NA 6.13% Fixed due November 11, 2021
Debt Instrument [Line Items]
Debt assumed			$ 12,000,000