The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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GOODWILL AND OTHER INTANGIBLE ASSETS, NET - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 44.6	$ 36.2	$ 27.1
Expected amortization expense in 2022	53.8
Expected amortization expense in 2023	53.8
Expected amortization expense in 2024	50.4
Expected amortization expense in 2025	49.6
Expected amortization expense in 2026	48.4
Silgan Specialty Packaging And Unicep Packaging \| Customer Relationships
Goodwill [Line Items]
Customer relationship intangible asset	246.1
Silgan Specialty Packaging And Unicep Packaging \| Technology-Based Intangible Assets
Goodwill [Line Items]
Customer relationship intangible asset	8.6
Silgan Specialty Packaging And Unicep Packaging \| Trade names
Goodwill [Line Items]
Customer relationship intangible asset	$ 4.8