Other Financial Information - Noncash Operating Working Capital (Increase) Decrease) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Net (increase) decrease in operating working capital, excluding cash and cash equivalents:
(Increase) decrease in accounts receivable	$ 47,151	$ (137,228)	$ 8,056
(Increase) decrease in inventories	329	(1,534)	12,809
(Increase) decrease in prepaid expenses	(1,293)	(3,413)	2,003
Increase (decrease) in accounts payable and accrued liabilities	(140,011)	69,854	95,166
Increase (decrease) in income taxes payable	(5,537)	6,593	423
Net (increase) decrease in noncash operating working capital	(99,361)	(65,728)	118,457
Supplementary disclosures:
Cash income taxes paid, net of refunds	12,356	24,853	2,138
Interest paid, net of amounts capitalized of $14.5 million in 2023, $16.3 million in 2022 and $16.1 million in 2021	108,912	149,957	165,699
Capitalized interest paid	14,500	16,300	16,100
Non-cash investing activities:
Asset retirement costs capitalized	32,975	(21,147)	54,439
(Increase) decrease in capital expenditure accrual	$ 17,517	$ (31,397)	$ 9,788