Other Accrued Expense (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Schedule of Other Accrued Expense [Line Items]
Asset Retirement Obligation, Current	$ 30,348
Other accrued expenses	81,892	$ 70,462
Current Liabilities
Schedule of Other Accrued Expense [Line Items]
Accrued Employee Benefits, Current	19,833	21,611
Asset Retirement Obligation, Current	30,348	32,200
Accrued Environmental Loss Contingencies, Current	11,988	2,256
Operating and Finance Lease Liability, Current	8,809	5,926
Other Accrued Liabilities	10,914	8,469
Other accrued expenses	$ 81,892	$ 70,462