DESCRIPTION OF BUSINESS (Details)	Sep. 30, 2019 hotel Room State	Sep. 30, 2018 Room
Properties
Number of hotels \| hotel	70
Number of guestrooms \| Room	88	150
Number of states in which hotel properties are located \| State	24
Hotels
Properties
Number of hotels \| hotel	70
Number of guestrooms \| Room	10,803
All hotels other than one acquired in 2019 through joint venture \| Hotels
Properties
Ownership percentage of equity interests	100.00%
One hotel acquired in 2019 through joint venture \| Hotels
Properties
Ownership percentage of equity interests	51.00%

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

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
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Period Type:	instant

- Definition

The number of states the entity operates in as of the balance sheet date.

+ References

No definition available.

+ Details

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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

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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

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	srt_OwnershipAxis=inn_AllHotelsOtherThanOneAcquiredIn2019ThroughJointVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=inn_OneHotelAcquiredIn2019ThroughJointVentureMember
Namespace Prefix:
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