Environmental Environmental (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
Loss Contingencies [Line Items]
Environmental remediation expense	$ 0.5	$ 0.1	$ 0.7	$ 0.1
Accrued environmental expense	5.7		5.7		$ 5.5
Accrued environmental expense, noncurrent	3.5		3.5
Affiliated Entity
Loss Contingencies [Line Items]
Accrued environmental expense	$ 0.4	$ 0.5	$ 0.4	$ 0.5