CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Postretirement plans:
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest	$ 0.0	$ 0.3	$ (0.2)
Pension Plans [Member]
Pension Plan and Restoration of Retirement Income Plan:
Amortization of prior service cost, net of tax of $0.1, $0.0 and $0.0, respectively	0.1	0.0	0.0
Amortization of deferred net loss, net of tax of $0.2, $0.9 and $1.2, respectively	0.2	0.9	1.2
Net gain (loss) arising during the period, net of tax of ($2.4), $0.0 and ($1.7), respectively	(2.4)	0.0	(1.7)
Prior service cost arising during the period, net of tax of $0.0, ($0.3) and $0.0, respectively	0.0	(0.3)	0.0
Settlement cost, net of tax of $4.3, $2.7 and $0.7, respectively	4.3	2.7	0.7
Other Postretirement Benefits Plan [Member]
Postretirement plans:
Amortization of prior service credit, net of tax of ($0.1), ($0.4) and ($0.6), respectively	(0.1)	(0.4)	(0.6)
Amortization of deferred net (gain) loss, net of tax of $0.0, $0.0 and $0.0, respectively	0.0	0.0	0.0
Net gain (loss) arising during the period, net of tax of $1.7, ($0.2) and ($0.8), respectively	1.7	(0.2)	(0.8)
Curtailment cost, net of tax of $0.0, $0.0 and ($0.1), respectively	$ 0.0	$ 0.0	$ (0.1)