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Acquisitions - Preliminary Intangible Assets Acquired (Details) - USD ($) $ in Thousands		12 Months Ended
	Jul. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisitions (Note 2)		$ 8,180	$ 0	$ 139,257
Sotera Health LLC's Nordion Medical Isotope Business | Technical support agreement
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisitions (Note 2)	$ 67,500
Acquired finite-lived intangible assets, weighted average useful life	23 years
Sotera Health LLC's Nordion Medical Isotope Business | Unpatented technology
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisitions (Note 2)	$ 33,000
Acquired finite-lived intangible assets, weighted average useful life	23 years
Sotera Health LLC's Nordion Medical Isotope Business | Favorable operating lease
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisitions (Note 2)	$ 28,157
Sotera Health LLC's Nordion Medical Isotope Business | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Acquisitions (Note 2)	$ 10,600
Acquired finite-lived intangible assets, weighted average useful life	23 years
Minimum | Sotera Health LLC's Nordion Medical Isotope Business | Unpatented technology
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets, weighted average useful life	13 years
Maximum | Sotera Health LLC's Nordion Medical Isotope Business | Unpatented technology
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets, weighted average useful life	30 years

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Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
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Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, from an acquisition.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
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