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Basis of Presentation and Significant Accounting Policies - Additional Information (Details) $ in Thousands			3 Months Ended		6 Months Ended
	Apr. 17, 2018 center personnel	Mar. 02, 2016 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) component segment	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of reportable segments | segment					3
Number of components supplied to worldwide (more than) | component					1,300
Accumulated other comprehensive income			$ (1,248)		$ (1,248)		$ (9,454)
Total inventories			11,700		11,700		8,600
Restricted cash and cash equivalents			$ 8,500		$ 8,500
Effective tax rate			23.30%	30.60%	22.60%	30.60%
Effective income tax rate reconciliation, share-based compensation cost (benefit) amount			$ (200)	$ (2,600)	$ (2,400)	$ (4,900)
Gross unrecognized tax benefits			800		800
Increase in cash and cash equivalents and restricted cash and cash equivalents			326,141	$ 157,930	326,141	$ 157,930	213,144	$ 134,600
Accounting Standards Update 2016-01
Basis Of Presentation And Significant Accounting Policies [Line Items]
Accumulated other comprehensive income							$ 2,200
Cash Held for Future Decommissioning of Facilities
Basis Of Presentation And Significant Accounting Policies [Line Items]
Restricted cash and cash equivalents			2,600		2,600
Cash Held to Meet Reinsurance Reserve Requirements
Basis Of Presentation And Significant Accounting Policies [Line Items]
Restricted cash and cash equivalents			$ 5,900		$ 5,900
Unsuccessful Outcome of Framework Agreement
Basis Of Presentation And Significant Accounting Policies [Line Items]
Loss contingency as a result of the Framework Agreement		$ 30,000
Canada Revenue Agency
Basis Of Presentation And Significant Accounting Policies [Line Items]
Statutory tax rate for Canada operations					25.00%
Sotera Health LLC's Nordion Medical Isotope Business
Basis Of Presentation And Significant Accounting Policies [Line Items]
Number of personnel acquired | personnel	150
Number of businesses acquired | center	2

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