Annual report pursuant to Section 13 and 15(d)

Goodwill and Intangible Assets Goodwill and Intangible Assets - Phantom (Details)

v3.20.1
Goodwill and Intangible Assets Goodwill and Intangible Assets - Phantom (Details) - USD ($)
$ in Millions
12 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Amortizing Intangibles:    
Finite-Lived Intangible Assets, Amortization Expense, Year Two $ 4.5  
Finite-Lived Intangible Assets, Amortization Expense, Year Three 4.5  
Amortization expense, year four 4.5  
Finite-Lived Intangible Assets, Amortization Expense, Year Five 4.5  
Finite-Lived Intangible Assets, Amortization Expense, after Year Five 11.9  
Patents [Member]    
Amortizing Intangibles:    
Finite-Lived Intangible Assets, Amortization Expense, Year Two 1.4  
Finite-Lived Intangible Assets, Amortization Expense, Year Three 1.4  
Amortization expense, year four 1.4  
Finite-Lived Intangible Assets, Amortization Expense, Year Five 1.4  
Finite-Lived Intangible Assets, Amortization Expense, after Year Five $ 6.1  
Patents [Member] | Minimum    
Amortizing Intangibles:    
Useful life 10 years 10 years
Patents [Member] | Maximum [Member]    
Amortizing Intangibles:    
Useful life 18 years 18 years
Customer Relationships [Member]    
Amortizing Intangibles:    
Finite-Lived Intangible Assets, Amortization Expense, Year Two $ 3.1  
Finite-Lived Intangible Assets, Amortization Expense, Year Three 3.1  
Amortization expense, year four 3.1  
Finite-Lived Intangible Assets, Amortization Expense, Year Five 3.1  
Finite-Lived Intangible Assets, Amortization Expense, after Year Five $ 5.8  
Useful life 12 years 2 months 12 days 12 years 3 months 12 days
Customer Relationships [Member] | Minimum    
Amortizing Intangibles:    
Useful life 10 years 10 years
Customer Relationships [Member] | Maximum [Member]    
Amortizing Intangibles:    
Useful life 21 years 21 years