FAIR VALUE MEASUREMENTS (Tables)

The following assets and liabilities are measured at fair value on a recurring basis:



	March 31, 2018
	Level 1			Level 2			Level 3		Total
	(Thousands of Dollars)
Assets:
Other current assets:
Interest rate swaps	$	—		$	5,547		$	—	$	5,547
Other long-term assets, net:
Interest rate swaps	—			2,307			—		2,307
Total	$	—		$	7,854		$	—	$	7,854
Liabilities:
Accrued liabilities:
Commodity derivatives	$	(257	)	$	—		$	—	$	(257	)
Interest rate swaps	—			(114		)	—		(114		)
Other long-term liabilities:
Interest rate swaps	—			(307		)	—		(307		)
Total	$	(257	)	$	(421	)	$	—	$	(678	)



	December 31, 2017
	Level 1			Level 2			Level 3		Total
	(Thousands of Dollars)
Assets:
Other current assets:
Product imbalances	$	3,890		$	—		$	—	$	3,890
Liabilities:
Accrued liabilities:
Product imbalances	$	(1,534	)	$	—		$	—	$	(1,534	)
Commodity derivatives	(878		)	—			—		(878		)
Interest rate swaps	—			(5,394		)	—		(5,394		)
Other long-term liabilities:
Interest rate swaps	—			(4,594		)	—		(4,594		)
Total	$	(2,412	)	$	(9,988	)	$	—	$	(12,400	)

The estimated fair values and carrying amounts of long-term debt, including the current portion, were as follows:



	March 31, 2018		December 31, 2017
	(Thousands of Dollars)
Fair value	$	3,665,335	$	3,677,622
Carrying amount	$	3,656,066	$	3,613,059

- Definition

Tabular disclosure of financial instruments measured at fair value, including those classified in shareholders' equity measured on a recurring or nonrecurring basis. Disclosures include, but are not limited to, fair value measurements recorded and the reasons for the measurements, level within the fair value hierarchy in which the fair value measurements are categorized and transfers between levels 1 and 2. Nonrecurring fair value measurements are those that are required or permitted in the statement of financial position in particular circumstances.

+ References + Details