Benefit Plans, Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Change in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income [Abstract]
Total recognized in other comprehensive income	$ (5.6)	$ (35.3)	$ (45.2)
Pension Benefits [Member]
Change in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income [Abstract]
Current year actuarial gain (loss)	3.8	31.2
Amortization of actuarial (gain) loss	2.2	4.0
Total recognized in other comprehensive income	6.0	35.2
Post-Retirement Benefits [Member]
Change in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income [Abstract]
Current year actuarial gain (loss)	(0.1)	0.4
Amortization of actuarial (gain) loss	(0.3)	(0.3)
Total recognized in other comprehensive income	$ (0.4)	$ 0.1