Segment Information - Revenue from External Customers by Products and Services (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue from External Customer [Line Items]
Total revenues	$ 175.8	$ 180.0	$ 339.0	$ 346.2
Medical | Medical
Revenue from External Customer [Line Items]
Total revenues	66.8	52.1	126.9	103.6
Reactor Safety and Control Systems | Industrial
Revenue from External Customer [Line Items]
Total revenues	34.7	42.7	65.5	79.6
Radiological Search, Measurement, and Analysis Systems | Industrial
Revenue from External Customer [Line Items]
Total revenues	$ 74.3	$ 85.2	$ 146.6	$ 163.0