Income Tax Matters - Income Tax (Provision) Benefit by Region (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Domestic	$ 0.1	$ (1.0)	$ (6.9)	$ 0.9
Foreign	(0.2)	(0.1)	(1.1)	(1.2)
Total	$ (0.1)	$ (1.1)	$ (8.0)	$ (0.3)