FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Mar. 31, 2016

Fair Value Disclosures [Abstract]

Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]

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



	March 31, 2016
	Level 1				Level 2				Level 3				Total
	(Thousands of Dollars)
Assets:
Other current assets:
Product imbalances	$	4,321			$	—			$	—			$	4,321
Commodity derivatives	1,671				69				—				1,740
Total	$	5,992			$	69			$	—			$	6,061
Liabilities:
Accrued liabilities:
Product imbalances	$	(433	)		$	—			$	—			$	(433	)
Commodity derivatives	(751		)		(133		)		—				(884		)
Other long-term liabilities:
Guarantee liability	—				—				(1,400		)		(1,400		)
Interest rate swaps	—				(28,675		)		—				(28,675		)
Total	$	(1,184	)		$	(28,808	)		$	(1,400	)		$	(31,392	)



	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	)

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

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



	Three Months Ended March 31, 2016
	(Thousands of Dollars)
Beginning balance	$	1,697
Adjustments to guarantee liability	(297		)
Ending balance	$	1,400

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

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



	March 31, 2016								December 31, 2015
	Fair Value				Carrying Amount				Fair Value				Carrying Amount
	(Thousands of Dollars)
Long-term debt	$	2,980,166			$	3,125,650			$	2,929,438			$	3,055,612
Axeon Term Loan	$	173,197			$	170,055			$	172,123			$	170,352