Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ (287.8)	$ 36.8	$ (125.5)	$ 66.9
Derivative financial instruments:
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(1.7)	(8.0)	(27.3)	(13.5)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	0.5	2.4	8.2	4.1
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	4.9	1.0	5.9	1.9
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	1.2	0.0	1.7	0.4
Defined benefit plans:
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), after Tax	0.2	0.0	0.4	0.0
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax	0.1	0.0	0.2	0.0
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax	1.2	0.8	2.4	1.6
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax	0.3	0.3	0.6	0.6
Other Comprehensive Income (Loss), Net of Tax, Total	4.6	(6.2)	(18.6)	(10.0)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest, Total	(283.2)	30.6	(144.1)	56.9
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	(80.6)	0.7	(79.7)	0.5
Comprehensive Income (Loss), Net of Tax, Attributable to Parent, Total	$ (202.6)	$ 29.9	$ (64.4)	$ 56.4