CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Other comprehensive income (loss), net of tax
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 279.5	$ 52.7
Pension Plan and Restoration of Retirement Income Plan:
Amortization of prior service cost, net of tax of $0.0 and $0.0, respectively	0.1	0.0
Amortization of deferred net loss, net of tax of $0.1 and $0.2, respectively	0.3	0.6
Settlement cost, net of tax of $2.2 and $1.0, respectively	7.4	3.1
Postretirement Benefit Plans:
Amortization of prior service credit, net of tax of $0.0 and ($0.1), respectively	0.0	(0.3)
Other comprehensive gain from unconsolidated affiliates, net of tax of $0.0 and $0.0, respectively	0.0	(0.1)
Other comprehensive income, net of tax	7.8	3.5
Comprehensive income	$ 287.3	$ 56.2