Concentration of Risk Other accrued expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Schedule of Other Accrued Expense [Line Items]
Accrued Employee Benefits, Current	$ 21,611	$ 25,811
Asset Retirement Obligation, Current	32,200	25,598
Accrued Environmental Loss Contingencies, Current	2,256	3,038
Operating and Finance Lease Liability, Current	5,926	1,779
Other Accrued Liabilities	8,469	18,907
Other accrued expenses	$ 70,462	$ 75,133