STOCK-BASED COMPENSATION (Tables)

6 Months Ended

Jun. 30, 2014

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Share Based Compensation Expense

The table below sets forth the total amount of stock-based compensation expense for the six months and quarters ended June 30, 2014 and 2013.

	Quarter Ended June 30,				Six Months Ended June 30,
	2014		2013		2014		2013
	(Thousands of dollars)
Stock-based compensation expense:
Time-based restricted units	$	322	$	113	$	450	$	222
Performance-based restricted units		720		486		1,281		777
Total stock-based compensation expense	$	1,042	$	599	$	1,731	$	999