Supplemental Cash Flow Information (Details) - USD ($) shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Supplemental Cash Flow Elements [Abstract]
Interest, net of capitalized interest	$ 41,880	$ 51,556
Income taxes	(1,057)	(204)
Change in accounts payable related to capital expenditures	21,216	(31,403)
Asset Retirement Obligation, Period Increase (Decrease)	$ (1,538)	$ 44,339
Noncash or Part Noncash Acquisition, Noncash Financial or Equity Instrument Consideration, Shares Issued	0	1,009,015
Operating Lease, Payments	$ 5,848	$ 6,714
Operating Cash Flow from Financing Leases	77	155
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	1,189	4,217
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 2,055	$ 703