Restructuring and Related Activities - Restructuring Charges by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Restructuring Cost and Reserve
Restructuring charges	$ 3.9	$ 1.8
Restructuring and Related Cost, Incurred Cost	4.1
Severance Pay and Contract Termination and Other Costs
Restructuring Cost and Reserve
Restructuring charges	5.3	2.3
Severance Pay and Benefits
Restructuring Cost and Reserve
Restructuring and Related Cost, Incurred Cost	4.0
Contract Termination and Other Costs
Restructuring Cost and Reserve
Restructuring and Related Cost, Incurred Cost	0.1
Operating Segments | Audio | Severance Pay and Contract Termination and Other Costs
Restructuring Cost and Reserve
Restructuring charges	4.1	1.8
Operating Segments | Precision Devices | Severance Pay and Contract Termination and Other Costs
Restructuring Cost and Reserve
Restructuring charges	0.0	0.3
Corporate | Severance Pay and Contract Termination and Other Costs
Restructuring Cost and Reserve
Restructuring charges	1.2	0.2
Cost of Goods Sold, Restructuring Charges | Severance Pay and Contract Termination and Other Costs
Restructuring Cost and Reserve
Restructuring charges	1.4	0.5
Operating Expense | Severance Pay and Contract Termination and Other Costs
Restructuring Cost and Reserve
Restructuring charges	$ 3.9
Restructuring Charges | Severance Pay and Contract Termination and Other Costs
Restructuring Cost and Reserve
Restructuring charges		$ 1.8