Environmental Environmental (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Environmental remediation expense	$ 1,000	$ 300	$ 1,600
Accrued environmental expense liability	5,700		5,700	$ 5,500
Accrued environmental expense, noncurrent liability	3,500		3,500
Affiliated Entity
Loss Contingencies [Line Items]
Accrued environmental expense liability	$ 400	$ 500	$ 400