Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Income tax expense	$ 18.3	$ 23.0	$ 12.9	$ 44.0
Income before income taxes and equity income of unconsolidated entity	$ 84.7	$ 108.9	$ 59.4	$ 207.8
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward					$ 32.0