Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Stockholders' Equity [Abstract]
Minimum pension and post retirement benefit plan adjustments, net of taxes	$ 41	$ 36	$ 449

Other Comprehensive Income Minimum Pension Liability Net Adjustment Tax 1

No definition available.

Name:	rock_OtherComprehensiveIncomeMinimumPensionLiabilityNetAdjustmentTax1
Namespace Prefix:	rock_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration