Other Financial Information (Tables)

12 Months Ended

Dec. 31, 2016

Other Financial Information [Abstract]

Noncash Operating Working Capital (Increase) Decrease

(Thousands of dollars)	2016		2015	2014
Accounts receivable	$	119,671	297,625	175,820
Inventories		(5,171)	(15,340)	25,697
Prepaid expenses		149,946	(144,845)	6,575
Deferred income tax assets		-	3,924	6,884
Accounts payable and accrued liabilities		(328,078)	(36,887)	(54,785)
Current income tax liabilities		24,943	(69,413)	(163,920)
Net (increase) decrease in noncash operating working capital	$	(38,689)	35,064	(3,729)
Supplementary disclosures (including discontinued operations):
Cash income taxes paid, net of refunds	$	6,707	118,667	573,799
Interest paid, net of amounts capitalized		127,798	110,386	114,232
Noncash investing activities, related to continuing operations:
Asset retirement costs capitalized	$	13,690	76,775	70,568
Decrease in capital expenditure accrual		158,885	462,474	93,080