Exit Activity Costs and Asset Impairments (Narrative) (Details) - facility	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021
Restructuring and Related Activities [Abstract]
Number of facilities closed	1	2

Restructuring and Related Cost, Number of Facilities to be Closed

No definition available.

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Namespace Prefix:	rock_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration