CREDIT QUALITY ASSESSMENT (Troubled Debt Restructured Loans for Specific Segments of the Loan Portfolio) (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2019	Dec. 31, 2018
Financing Receivable Modifications [Line Items]
Restructured accruing	$ 945	$ 0
Restructured non-accruing	1,050	1,622
Balance	1,995	1,622
Specific allowance	457	563
Restructured and subsequently defaulted	0	0
Commercial
Financing Receivable Modifications [Line Items]
Restructured accruing	170	0
Restructured non-accruing	261	1,464
Balance	431	1,464
Specific allowance	243	563
Restructured and subsequently defaulted	0	0
All Other
Financing Receivable Modifications [Line Items]
Restructured accruing	0	0
Restructured non-accruing	0	0
Balance	0	0
Specific allowance	0	0
Restructured and subsequently defaulted	0	0
Commercial Portfolio Segment \| Commercial Acquisition, Development and Construction
Financing Receivable Modifications [Line Items]
Restructured accruing	0	0
Restructured non-accruing	0	0
Balance	0	0
Specific allowance	0	0
Restructured and subsequently defaulted	0	0
Commercial Portfolio Segment \| Commercial Investor Real Estate
Financing Receivable Modifications [Line Items]
Restructured accruing	775	0
Restructured non-accruing	789	0
Balance	1,564	0
Specific allowance	214	0
Restructured and subsequently defaulted	0	0
Commercial Portfolio Segment \| Commercial Owner Occupied Real Estate
Financing Receivable Modifications [Line Items]
Restructured accruing	0	0
Restructured non-accruing	0	158
Balance	0	158
Specific allowance	0	0
Restructured and subsequently defaulted	$ 0	$ 0

- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

No definition available.

+ Details

Name:	sasr_FinancingReceivableModificationSubsequentDefaultRecordedInvestment
Namespace Prefix:	sasr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months.

+ References

No definition available.

+ Details

Name:	sasr_FinancingReceivableTroubledDebtRestructuringsBalancePrevious12Months
Namespace Prefix:	sasr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which restructured accruing.

+ References

No definition available.

+ Details

Name:	sasr_FinancingReceivableTroubledDebtRestructuringsRestructuredAccruingPrevious12Months
Namespace Prefix:	sasr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which restructured non accruing.

+ References

No definition available.

+ Details

Name:	sasr_FinancingReceivableTroubledDebtRestructuringsRestructuredNonAccruingPrevious12Months
Namespace Prefix:	sasr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings previous 12 months, for specific allowance.

+ References

No definition available.

+ Details

Name:	sasr_FinancingReceivableTroubledDebtRestructuringsSpecificAllowance
Namespace Prefix:	sasr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_FinancingReceivableModificationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=sasr_AllOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=sasr_AcquisitionDevelopmentAndConstructionMortgageLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_InvestorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=sasr_CommercialMortgageLoansOwnerOccupiedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: