Commitments and Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Environmental liabilities	$ 1,100		$ 1,100
Dutch income tax liability	6,600	$ 6,300
Dutch income tax liability, net settlement	6,300
Nashville, TN
Loss Contingencies [Line Items]
Environmental liabilities	1,100
Nashville, TN | Minimum
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	900
Nashville, TN | Maximum
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies	$ 1,300