FAIR VALUE MEASUREMENTS (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Fair Value, Measurement Inputs, Disclosure [Text Block]

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



	December 31, 2015
	Level 1				Level 2				Level 3				Total
	(Thousands of Dollars)
Assets:
Other current assets:
Product imbalances	$	179			$	—			$	—			$	179
Commodity derivatives	11,325				77				—				11,402
Other long-term assets, net:
Interest rate swaps	—				2,755				—				2,755
Total	$	11,504			$	2,832			$	—			$	14,336
Liabilities:
Accrued liabilities:
Product imbalances	$	(419	)		$	—			$	—			$	(419	)
Commodity derivatives	—				(120		)		—				(120		)
Other long-term liabilities:
Guarantee liability	—				—				(1,697		)		(1,697		)
Interest rate swaps	—				(1,452		)		—				(1,452		)
Total	$	(419	)		$	(1,572	)		$	(1,697	)		$	(3,688	)



	December 31, 2014
	Level 1				Level 2				Level 3				Total
	(Thousands of Dollars)
Assets:
Other current assets:
Product imbalances	$	117			$	—			$	—			$	117
Commodity derivatives	11,009				5,353				—				16,362
Total	$	11,126			$	5,353			$	—			$	16,479
Liabilities:
Accrued liabilities:
Product imbalances	$	(1,388	)		$	—			$	—			$	(1,388	)
Commodity derivatives	—				(4,623		)		—				(4,623		)
Other long-term liabilities:
Guarantee liability	—				—				(580		)		(580		)
Total	$	(1,388	)		$	(4,623	)		$	(580	)		$	(6,591	)

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

The following table summarizes the activity in our Level 3 liabilities:



	Year Ended December 31, 2015
	(Thousands of Dollars)
Beginning balance	$	580
Adjustment to guarantee liability	1,117
Ending balance	$	1,697

Fair Value and Carrying Value of Debt and Note Receivable [Text Block]

The estimated fair values and carrying amounts of the long-term debt and the Axeon Term Loan were as follows:



	December 31, 2015								December 31, 2014
	Fair Value				Carrying Amount				Fair Value				Carrying Amount
	(Thousands of Dollars)
Long-term debt	$	2,929,438			$	3,079,349			$	2,764,242			$	2,749,452
Axeon Term Loan	$	172,123			$	170,352			$	164,386			$	169,235