EQUITY AWARDS - Schedule of Nonvested Stock Option Activity (Parenthetical) (Details)	9 Months Ended
Sep. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock dividend percentage	10.00%

Share based compensation arrangement by share based payment award nonvested options stock dividend percentage.

No definition available.

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Namespace Prefix:	gnty_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration