Other Financial Information - Noncash Operating Working Capital (Increase) Decrease) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net decrease (increase) in operating working capital, excluding cash and cash equivalents:
Decrease (increase) in accounts receivable	$ 8,056	$ 164,613	$ (232,037)
Decrease in inventories	12,809	5,953	10,258
Decrease in prepaid expenses	2,003	7,178	4,650
Increase (decrease) in accounts payable and accrued liabilities	95,166	(208,740)	196,773
Increase (decrease) in income taxes payable	423	(1,031)	3,469
Net decrease (increase) in noncash operating working capital	118,457	(32,027)	(16,887)
Supplementary disclosures:
Cash income taxes paid, net of refunds	2,138	(44,175)	(6,645)
Interest paid, net of amounts capitalized of $16.1 million in 2021, $8.0 million in 2020 and $1.8 million in 2019	165,699	191,561	179,722
Capitalized interest paid	16,100	8,000	1,800
Non-cash investing activities:
Asset retirement costs capitalized	54,439	14,736	33,874
(Increase) decrease in capital expenditure accrual	$ 9,788	$ 84,645	$ (73,426)