Financial Instruments and Risk Management (Tables)

9 Months Ended

Sep. 30, 2019

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Fair Value of Derivative Instruments Not Designated as Hedging Instruments

At September 30, 2019 and December 31, 2018, the fair value of derivative instruments not designated as hedging instruments are presented in the following table.

	September 30, 2019			December 31, 2018
(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	$	104,358	Accounts receivable	$	3,837

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

For the three-month and nine-month periods ended September 30, 2019 and September 30, 2018, the gains and losses recognized in the Consolidated Statements of Operations for derivative instruments not designated as hedging instruments are presented in the following table.

		Gain (Loss)				Gain (Loss)
(Thousands of dollars)		Three Months Ended September 30,				Nine months ended September 30,
Type of Derivative Contract	Statement of Operations Location	2019		2018		2019	2018
Commodity	Gain (loss) on crude contracts	$	63,247	(2,223	)	121,163	(69,349	)

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

The carrying value of assets and liabilities recorded at fair value on a recurring basis at September 30, 2019 and December 31, 2018, are presented in the following table.

	September 30, 2019					December 31, 2018
(Thousands of dollars)	Level 1		Level 2	Level 3	Total	Level 1	Level 2	Level 3	Total
Assets:
Commodity derivative contracts	$	—	104,358	—	104,358	—	3,837	—	3,837
	$	—	104,358	—	104,358	—	3,837	—	3,837
Liabilities:
Nonqualified employee savings plans	$	15,499	—	—	15,499	13,845	—	—	13,845
Contingent consideration	—		—	137,688	137,688	—	—	47,730	47,730
	$	15,499	—	137,688	153,187	13,845	—	47,730	61,575