Other Financial Information

3 Months Ended

Mar. 31, 2018

Other Financial Information [Abstract]

Other Financial Information

Note G – Other Financial Information

Additional disclosures regarding cash flow activities are provided below.

	Three Months Ended March 31,
(Thousands of dollars)	2018		2017
Net (increase) decrease in operating working capital other than    cash and cash equivalents:
Decrease in accounts receivable	$	30,467	36,246
Decrease in inventories		12,189	4,497
Decrease (increase) in prepaid expenses		(5,031)	17,788
Decrease in accounts payable and accrued liabilities		(25,270)	(44,240)
Increase in income taxes payable		29,199	29,127
Net decrease in noncash operating working capital	$	41,554	43,418
Supplementary disclosures:
Cash income taxes paid, net of refunds	$	7,940	3,422
Interest paid, net of amounts capitalized of $1,139 in 2018 and $1,093 in 2017		35,666	17,720
Non-cash investing activities:
Asset retirement costs capitalized	$	727	565
Decrease (increase) in capital expenditure accrual		(10,757)	12,906