Segment Information - Revenue from External Customers by Products and Services (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue from External Customer [Line Items]
Total revenues	$ 163.2	$ 166.2
Medical | Medical
Revenue from External Customer [Line Items]
Total revenues	60.1	51.5
Reactor Safety and Control Systems | Industrial
Revenue from External Customer [Line Items]
Total revenues	30.8	36.9
Radiological Search, Measurement, and Analysis Systems | Industrial
Revenue from External Customer [Line Items]
Total revenues	$ 72.3	$ 77.8