Income Taxes - Income tax expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Components of income tax benefit (expense) from continuing operations
Income tax expense	$ 1.4	$ 3.2	$ 2.2	$ 6.2