Revenue Recognition (Net Contract Assets (Liabilities)) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Revenue Recognition and Deferred Revenue [Abstract]
Contract assets	$ 2.0		$ 2.0		$ 2.2
Contract liabilities - current	(5.0)		(5.0)		(4.7)
Contract liabilities - noncurrent	(7.8)		(7.8)		(7.5)
Total	(10.8)		(10.8)		$ (10.0)
Contract with Customer, Liability, Revenue Recognized	$ 0.4	$ 1.2	$ 6.1	$ 4.2