LOANS AND ALLOWANCE FOR CREDIT LOSSES - Weighted Average Interest Rate on Loans Receivable (Details)	Mar. 31, 2021	Dec. 31, 2020
LOANS AND ALLOWANCE FOR CREDIT LOSSES
Loans Receivable, Weighted Average Interest Rate	4.30%	4.29%

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

No definition available.

Name:	gsbc_LoansReceivableWeightedAverageInterestRate
Namespace Prefix:	gsbc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant