Other Financial Information (Tables)

6 Months Ended

Jun. 30, 2021

Other Financial Information [Abstract]

Noncash Operating Working Capital (Increase) Decrease

Additional disclosures regarding cash flow activities are provided below.

	Six Months Ended June 30,
(Thousands of dollars)	2021		2020
Net (increase) decrease in operating working capital, excluding cash and cash equivalents:
(Increase) decrease in accounts receivable ¹	$	(104,775)	227,710
Decrease in inventories	8,938		13,968
(Increase) in prepaid expenses	(1,945)		(20,712)
Increase (decrease) in accounts payable and accrued liabilities ¹	124,699		(219,228)
(Decrease) in income taxes payable	(352)		(403)
Net decrease in noncash operating working capital	$	26,565	1,335
Supplementary disclosures:
Cash income taxes paid, net of refunds	$	1,474	(7)
Interest paid, net of amounts capitalized of $7.4 million in 2021 and $4.9 million in 2020	80,546		100,745
Non-cash investing activities:
Asset retirement costs capitalized ²	$	6,669	6,342
Decrease in capital expenditure accrual	20,614		58,602

1 Excludes receivable/payable balances relating to mark-to-market of crude contracts and contingent consideration relating to acquisitions.

2 Excludes non-cash capitalized cost offset by impairment of $74.4 million related to Terra Nova in 2021.