Unusual Items - Schedule of Unusual Items Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Unusual or Infrequent Item [Line Items]
Merger costs	$ (7.7)
Legal matter	0.4
Total unusual items	8.1	$ 0.3	$ 0.2
Aerospace and Defense
Unusual or Infrequent Item [Line Items]
Merger costs	0.2	0.0	0.0
Legal matter	0.4	0.0	0.0
Acquisition costs	0.0	0.3	0.0
Total unusual items	0.6	0.3	0.0
Corporate
Unusual or Infrequent Item [Line Items]
Merger costs	(7.5)	0.0	0.0
Loss on bank amendment	0.0	0.0	0.2
Total unusual items	$ 7.5	$ 0.0	$ 0.2