COMMITMENTS AND CONTINGENCIES (Tables)

12 Months Ended

Dec. 31, 2017

COMMITMENTS AND CONTINGENCIES [Abstract]

Future Minimum Property and Equipment Lease Payments under the Non-cancelable Operating Leases

Future minimum property and equipment lease payments under the non-cancelable operating leases at December 31, 2017, are as follows:

Year Ending December 31,
	(thousands of dollars)
2018	$	3,393
2019		3,341
2020		3,250
2021		3,120
2022		1,498
Thereafter		3,177
Total	$	17,779