Consolidated Statement of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021
Statement of Stockholders' Equity [Abstract]
Adjustment to pension benefit liability, taxes	$ 0	$ 10	$ 10	$ 10

Other Comprehensive Income Minimum Post Retirement Benefit Plan, Net Adjustment Tax 1

No definition available.

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