Represents the number of options to extend the lease term under lessee's leasing arrangement.

No definition available.

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

- Definition

The number of real estate properties for which land is leased under the agreement.

+ References

No definition available.

+ Details

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

- Definition

Number of Prepaid Land Lease

+ References

No definition available.

+ Details

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

- Definition

Amount of asset related to consideration paid for rent in advance of when the economic benefit of the cost will be realized, and which will be expensed in future periods with the passage of time or when a triggering event occurs.

+ References

No definition available.

+ Details

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

- Definition

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

No definition available.

+ Details

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

- Definition

Term of the lessee's leasing arrangement renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LesseeLeasingArrangementsOperatingLeasesRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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

- Details

Name:	us-gaap_OtherCommitmentsAxis=inn_OperatingGroundLeaseAgreementsMember
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_StatementGeographicalAxis=inn_PortlandOregonMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

COMMITMENTS AND CONTINGENCIES - Ground Leases (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) contract Property option	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Commitments and contingencies
Total rent expense \| $	$ 0.4	$ 0.4	$ 1.3	$ 1.2
Ground Leases \| Duluth, GA
Commitments and contingencies
Number of hotel properties for which land is leased			1
Ground Leases \| Portland, OR
Commitments and contingencies
Number of hotel properties for which land is leased			2
Number of Prepaid Land Lease \| contract			2
Remaining prepaid balance of land lease \| $	$ 3.2		$ 3.2		$ 3.3
Number of options to extend lease \| option			1
Lease renewal period			14 years
Ground Leases \| Houston (Galleria Area), TX
Commitments and contingencies
Number of hotel properties for which land is leased			1
Number of options to extend lease \| option			1
Lease renewal period			10 years
Ground Leases \| Austin, TX
Commitments and contingencies
Number of hotel properties for which land is leased			1
Ground Leases \| Baltimore, MD
Commitments and contingencies
Number of hotel properties for which land is leased			1
Number of options to extend lease \| option			12
Lease renewal period			5 years
Ground Leases \| Long Island (Garden City), NY
Commitments and contingencies
Number of hotel properties for which land is leased			1