Summary of Significant Accounting Policies - Summary of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive income (loss)	$ (11.9)	$ (24.8)
Other comprehensive income (loss) before reclassifications	2.5	(2.1)
Amounts reclassified from accumulated other comprehensive income (loss)	1.0	1.4
Settlement cost	1.2	13.6	$ 6.0
Net current period other comprehensive income (loss)	4.7	12.9	7.3
Accumulated other comprehensive income (loss)	(7.2)	(11.9)	(24.8)
Accumulated other comprehensive loss, net of tax	(7.2)	(11.9)
Net current period other comprehensive income (loss)	4.7	12.9	7.3
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net current period other comprehensive income (loss)	0.0
Defined Benefit Plans Income Loss [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive income (loss)	(17.5)	(24.9)
Other comprehensive income (loss) before reclassifications	3.3	(7.6)
Amounts reclassified from accumulated other comprehensive income (loss)	0.9	1.4
Net current period other comprehensive income (loss)	5.4	7.4
Accumulated other comprehensive income (loss)	(12.1)	(17.5)	(24.9)
Defined Benefit Plans Income Loss [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive income (loss)	6.6	1.1
Other comprehensive income (loss) before reclassifications	(0.8)	5.5
Amounts reclassified from accumulated other comprehensive income (loss)	(0.1)	0.0
Net current period other comprehensive income (loss)	(0.9)	5.5
Accumulated other comprehensive income (loss)	5.7	6.6	1.1
Defined Benefit Plan Prior Service Cost [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive income (loss)	(1.0)	(1.2)
Other comprehensive income (loss) before reclassifications	0.0	0.0
Amounts reclassified from accumulated other comprehensive income (loss)	0.2	0.2
Net current period other comprehensive income (loss)	0.2	0.2
Accumulated other comprehensive income (loss)	(0.8)	(1.0)	(1.2)
Defined Benefit Plan Prior Service Cost [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive income (loss)	0.0	0.2
Other comprehensive income (loss) before reclassifications	0.0	0.0
Amounts reclassified from accumulated other comprehensive income (loss)	0.0	(0.2)
Net current period other comprehensive income (loss)		(0.2)
Accumulated other comprehensive income (loss)	0.0	0.0	$ 0.2
Settlement Cost [Member] | Defined Benefit Plans Income Loss [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost	1.2	13.6
Settlement Cost [Member] | Defined Benefit Plan Prior Service Cost [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost	0.0	0.0
Settlement Cost [Member] | Defined Benefit Plan Prior Service Cost [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost	$ 0.0	$ 0.0