DESCRIPTION OF BUSINESS (Details)	Sep. 30, 2018 hotel Room State	Sep. 30, 2017 Room
Properties
Number of hotels \| hotel	77
Number of guestrooms \| Room	150	1,790
Number of states in which hotel properties are located \| State	26
Hotels
Properties
Number of hotels \| hotel	77
Number of guestrooms \| Room	11,659
TRS Lessees \| Operating partnership
Properties
Ownership interest in joint venture	100.00%

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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 states the entity operates in as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfStatesInWhichEntityOperates
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

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

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=us-gaap_HotelMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_OwnershipAxis=inn_TRSLesseesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=inn_SummitHotelOPLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: