v3.8.0.1
INTANGIBLE ASSETS (Tables)
 12 Months Ended
Dec. 31, 2017
Intangible Assets, Net (Excluding Goodwill) [Abstract]  
Schedule of Finite-Lived Intangible Assets by Major Class [Table Text Block]
Intangible assets consisted of the following:
 
 
 
December 31, 2017
 
December 31, 2016
 
Weighted-Average Amortization Period
 
Cost
 
Accumulated
Amortization
 
Cost
 
Accumulated
Amortization
 
(Years)
 
(Thousands of Dollars)
Customer contracts and relationships
18
 
$
863,950

 
$
(81,136
)
 
$
166,950

 
$
(41,582
)
Other
47
 
2,359

 
(694
)
 
2,359

 
(644
)
Total
 
 
$
866,309

 
$
(81,830
)
 
$
169,309

 
$
(42,226
)