v3.19.3.a.u2
ACCRUED LIABILITIES (Tables)
12 Months Ended
Dec. 31, 2019
Accrued Liabilities, Current [Abstract]  
Schedule of Accrued Liabilities [Table Text Block]
Accrued liabilities consisted of the following:
 
December 31,
 
2019
 
2018
 
(Thousands of Dollars)
Employee wages and benefit costs
$
36,704

 
$
29,518

Revenue contract liabilities
21,083

 
21,579

Interest rate swaps
19,169

 

Operating lease liabilities
10,416

 

Other
16,913

 
23,321

Accrued liabilities
$
104,285

 
$
74,418