XML 131 R66.htm IDEA: XBRL DOCUMENT v3.24.0.1
Intangible assets and goodwill - Summary Changes in Goodwill (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]      
Goodwill, beginning balance $ 218.2 $ 224.9  
Goodwill impairment (218.2) (6.7) $ (41.7)
Goodwill, ending balance 0.0 218.2 224.9
Commercial Products      
Goodwill and Intangible Assets Disclosure [Abstract]      
Goodwill, beginning balance 0.0 0.0  
Goodwill impairment 0.0 0.0  
Goodwill, ending balance 0.0 0.0 0.0
Goodwill [Roll Forward]      
Goodwill, gross 41.7 41.7 41.7
Goodwill, accumulated Impairment loss 41.7 41.7 41.7
MCM Products      
Goodwill and Intangible Assets Disclosure [Abstract]      
Goodwill, beginning balance 218.2 218.2  
Goodwill impairment (218.2) 0.0  
Goodwill, ending balance 0.0 218.2 218.2
Goodwill [Roll Forward]      
Goodwill, gross 218.2 218.2 218.2
Goodwill, accumulated Impairment loss 218.2    
Services      
Goodwill and Intangible Assets Disclosure [Abstract]      
Goodwill, beginning balance 0.0 6.7  
Goodwill impairment 0.0 (6.7)  
Goodwill, ending balance 0.0 0.0 6.7
Goodwill [Roll Forward]      
Goodwill, gross 6.7 6.7 $ 6.7
Goodwill, accumulated Impairment loss $ 6.7 $ 6.7