Loans and Allowance for Credit Losses - Weighted Average Interest Rate on Loans Receivable (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Loans and Allowance for Credit Losses
Loans Receivable weighted average interest rate	5.54%	4.26%
Commercial loan participations sold to other financial institutions	$ 422.3	$ 249.5
Residential mortgage loans sold	117.9	136.3
Unpaid principal balances
Loans and Allowance for Credit Losses
Loans serviced for others	540.2	385.8
Unused lines of Credit
Loans and Allowance for Credit Losses
Loans serviced for others	$ 104.1	$ 130.9

- Definition

Represents the monetary amount of Commercial loan participations sold to other financial institutions, during the indicated time period.

+ References

No definition available.

+ Details

Name:	gsbc_CommercialLoanParticipationsSoldToOtherFinancialInstitutions
Namespace Prefix:	gsbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the Loans Receivable weighted average interest rate, as of the indicated date.

+ References

No definition available.

+ Details

Name:	gsbc_LoansReceivableWeightedAverageInterestRate
Namespace Prefix:	gsbc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the monetary amount of Loans serviced for others, during the indicated time period.

+ References

No definition available.

+ Details

Name:	gsbc_LoansServicedForOthers
Namespace Prefix:	gsbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the monetary amount of Residential mortgage loans sold, during the indicated time period.

+ References

No definition available.

+ Details

Name:	gsbc_ResidentialMortgageLoansSold
Namespace Prefix:	gsbc_
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_FinancingReceivableAllowanceForCreditLossesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_FinancialInstrumentAxis=gsbc_UnpaidPrincipalBalancesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_UnusedLinesOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: