Restructuring (Textuals) (Details) - USD ($) $ in Millions	12 Months Ended			36 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2021
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 81.6	$ 50.2	$ 65.0
DN Now Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	81.6	50.2	58.9
DN Now Plan [Member] | Scenario, Forecast
Restructuring Cost and Reserve [Line Items]
Anticipated Annual Synergies				$ 500.0
DN2020 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			6.1
Severance
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 75.8	$ 50.1	$ 65.0