Financial Instruments and Risk Management (Tables)

9 Months Ended

Sep. 30, 2016

Financial Instruments and Risk Management [Abstract]

WTI Open Contracts

	Volumes
At September 30, 2016	(barrels per day)	Swap Prices
October – December 2016	25,000	$50.67	per barrel
January – December 2017	16,000	$50.34	per barrel
At September 30, 2015
October – December 2015	15,000	$63.30	per barrel

Fair Value of Derivative Instruments Not Designated as Hedging Instruments

	September 30, 2016			December 31, 2015
(Thousands of dollars)	Asset (Liability) Derivatives			Asset (Liability) Derivatives
Type of Derivative Contract	Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
Commodity	Accounts receivable	$	192	Accounts receivable	$	89,358
Foreign exchange	Accounts receivable		142	Accounts payable		(29)

Recognized Gains and Losses for Derivative Instruments Not Designated as Hedging Instruments

			Gain (Loss)
		Three Months Ended			Nine Months Ended
(Thousands of dollars)		September 30,			September 30,
Type of Derivative Contract	Statement of Operations Location		2016	2015	2016	2015
Commodity	Sales and other operating revenues	$	11,871	39,392	(22,678)	46,811
Foreign exchange	Interest and other income		143	33	26,929	47
		$	12,014	39,425	4,251	46,858

Carrying Value of Assets and Liabilities Recorded at Fair Value on Recurring Basis

	September 30, 2016					December 31, 2015
(Thousands of dollars)	Level 1		Level 2	Level 3	Total	Level 1	Level 2	Level 3	Total
Assets:
Foreign currency exchange         derivative contracts	$	–	142	–	142	–	–	–	–
Commodity derivative         contracts		–	192	–	192	–	89,358	–	89,358
	$	–	334	–	334	–	89,358	–	89,358
Liabilities:
Nonqualified employee         savings plans	$	13,637	–	–	13,637	12,971	–	–	12,971
Foreign currency exchange         derivative contracts		–	–	–	–	–	29	–	29
	$	13,637	–	–	13,637	12,971	29	–	13,000

Nonrecurring Fair Value Measurements

	September 30, 2016
						Total
					Net Book	Pretax
					Value	(Noncash)
	Fair Value				Prior to	Impairment
		Level 1	Level 2	Level 3	Impairment	Loss
(Thousands of dollars)
Assets:
Impaired proved properties
Canada	$	–	–	71,967	167,055	95,088

	September 30, 2015
						Total
					Net Book	Pretax
					Value	(Noncash)
	Fair Value				Prior to	Impairment
		Level 1	Level 2	Level 3	Impairment	Loss
(Thousands of dollars)
Assets:
Impaired proved properties
Gulf of Mexico	$	–	–	216,602	361,402	144,800
Western Canada		–	–	23,526	707,100	683,574
Malaysia		–	–	1,208,900	2,681,500	1,472,600
	$	–	–	1,449,028	3,750,002	2,300,974