Impairment and Other Charges (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Impairment and Other Charges
Long-lived asset impairments (1)	$ 204,765
Abandonment of assets (2)	5,976	$ 35,861
Pension settlement loss (3)	4,660
Severance costs	1,882	5,748
Assets held for sale write down (4)	192	14,326
Retirement of equipment		17,218
Inventory write-downs		9,077
Other	18	43
Total	$ 217,493	$ 82,273