Fair-Value Measurements (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest Rate Swap
Derivative [Line Items]
Interest income (expense), net		$ 5.4	$ (0.6)	$ 0.5
Interest Rate Swap Buyouts
Derivative [Line Items]
Interest income (expense), net		$ 1.4	$ 0.5	$ 0.6
Interest Rate Swap Buyouts | Subsequent Event
Derivative [Line Items]
Interest income (expense), net	$ 0.4