CREDIT QUALITY ASSESSMENT (Credit Quality of Loan Portfolio) (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	$ 31,928	$ 27,235
Non-accrual loans	37,323	33,583
Loans aquired with deteriorated credit quality	19,562
Current loans	6,481,177	6,484,869
Total loans	6,569,990	6,571,634
Commercial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	4,099	2,786
Non-accrual loans	8,013	7,086
Loans aquired with deteriorated credit quality	7,355	8,155
Current loans	750,193	778,237
Total loans	769,660	796,264
Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	3,435	5,567
Non-accrual loans	4,081	4,107
Loans aquired with deteriorated credit quality	1,224	1,272
Current loans	496,703	506,893
Total loans	505,443	517,839
Commercial Real Estate Portfolio Segment \| Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	277	474
Non-accrual loans	3,306	3,306
Loans aquired with deteriorated credit quality	0	0
Current loans	685,356	677,421
Total loans	688,939	681,201
Commercial Real Estate Portfolio Segment \| Commercial Investor Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	5,484	3,830
Non-accrual loans	6,071	5,355
Loans aquired with deteriorated credit quality	10,973	14,328
Current loans	1,940,351	1,934,882
Total loans	1,962,879	1,958,395
Commercial Real Estate Portfolio Segment \| Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,596	433
Non-accrual loans	5,992	4,234
Loans aquired with deteriorated credit quality	0	2,182
Current loans	1,209,125	1,196,054
Total loans	1,216,713	1,202,903
Residential Real Estate Portfolio Segment \| Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	15,341	10,919
Non-accrual loans	9,704	9,336
Loans aquired with deteriorated credit quality	10	10
Current loans	1,224,913	1,207,982
Total loans	1,249,968	1,228,247
Residential Real Estate Portfolio Segment \| Residential Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,696	3,226
Non-accrual loans	156	159
Loans aquired with deteriorated credit quality	0	0
Current loans	174,536	183,400
Total loans	176,388	186,785
31-60 days
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	22,459	21,963
31-60 days \| Commercial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,417	2,737
31-60 days \| Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,863	3,871
31-60 days \| Commercial Real Estate Portfolio Segment \| Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	277	474
31-60 days \| Commercial Real Estate Portfolio Segment \| Commercial Investor Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	3,669	3,041
31-60 days \| Commercial Real Estate Portfolio Segment \| Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,506	433
31-60 days \| Residential Real Estate Portfolio Segment \| Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	12,508	8,181
31-60 days \| Residential Real Estate Portfolio Segment \| Residential Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,219	3,226
61-90 days
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	9,158	4,783
61-90 days \| Commercial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	2,682	0
61-90 days \| Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,572	1,477
61-90 days \| Commercial Real Estate Portfolio Segment \| Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
61-90 days \| Commercial Real Estate Portfolio Segment \| Commercial Investor Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,815	789
61-90 days \| Commercial Real Estate Portfolio Segment \| Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
61-90 days \| Residential Real Estate Portfolio Segment \| Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	2,612	2,517
61-90 days \| Residential Real Estate Portfolio Segment \| Residential Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	477	0
> 90 days
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	311	489
> 90 days \| Commercial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	49
> 90 days \| Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	219
> 90 days \| Commercial Real Estate Portfolio Segment \| Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
> 90 days \| Commercial Real Estate Portfolio Segment \| Commercial Investor Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
> 90 days \| Commercial Real Estate Portfolio Segment \| Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	90	0
> 90 days \| Residential Real Estate Portfolio Segment \| Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	221	221
> 90 days \| Residential Real Estate Portfolio Segment \| Residential Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	$ 0	$ 0

Loans And Leases Receivable, Current

No definition available.

Name:	sasr_LoansAndLeasesReceivableCurrent
Namespace Prefix:	sasr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loan, owed to the investor at the reporting date, whether or not currently due and whether or not any such amounts have been written or charged off by the investor. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82894507&loc=d3e13503-111538

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

+ Details

Name:	us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesOutstandingBalance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5111-111524

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Recorded Investment in financing receivables that are past due at the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953401-111524

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentPastDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_FinancingReceivableRecordedInvestmentPastDueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524

+ Details

Name:	us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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

- Details

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

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
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:

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables30To59DaysPastDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables60To89DaysPastDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: