CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Other comprehensive income (loss), net of tax
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 52.7	$ (491.8)
Pension Plan and Restoration of Retirement Income Plan:
Amortization of deferred net loss, net of tax of $0.2 and $0.3, respectively	0.6	0.8
Settlement cost, net of tax of $1.0 and $0.0, respectively	3.1	0.0
Postretirement Benefit Plans:
Amortization of prior service credit, net of tax of ($0.1) and ($0.2), respectively	(0.3)	(0.4)
Other comprehensive gain (loss) from unconsolidated affiliates, net of tax of $0.0 and ($0.4), respectively	(0.1)	1.3
Other comprehensive income (loss), net of tax	3.5	(0.9)
Comprehensive income (loss)	$ 56.2	$ (492.7)