v3.5.0.2
EMPLOYEE BENEFIT PLANS (Tables)
 9 Months Ended
Sep. 30, 2016
Compensation and Retirement Disclosure [Abstract]  
Schedule of Defined Benefit Plans Disclosures [Table Text Block]
The reconciliation of funded status for the Pension Plans and other postretirement benefit plans as of December 31, 2015 was as follows:
 
Pension Plans
 
Other Postretirement
Benefits
 
(Thousands of Dollars)
Fair value of plan assets
$
87,706

 
$
—

Less: Benefit obligation
109,202

 
10,042

Funded status
$
(21,496
)
 
$
(10,042
)
Schedule of Net Benefit Costs [Table Text Block]
The following table summarizes the components of net periodic benefit costs for the Pension Plans and other postretirement benefits on a combined basis for periods prior to the Employee Transfer and after the Employee Transfer:
 
Pension Plans
 
Other Postretirement
Benefits
 
2016
 
2015
 
2016
 
2015
 
(Thousands of Dollars)
For the three months ended September 30:
 
 
 
 
 
 
 
Service cost
$
1,926

 
$
1,919

 
$
105

 
$
118

Interest cost
1,006

 
1,097

 
100

 
111

Expected return on assets
(1,353
)
 
(1,254
)
 
—

 
—

Amortization of prior service credit
(516
)
 
(516
)
 
(286
)
 
(285
)
Amortization of net loss
273

 
461

 
45

 
67

Net periodic benefit cost (income)
$
1,336

 
$
1,707

 
$
(36
)
 
$
11

 
 
 
 
 
 
 
 
For the nine months ended September 30:
 
 
 
 
 
 
 
Service cost
$
5,778

 
$
5,757

 
$
315

 
$
354

Interest cost
3,018

 
3,291

 
300

 
334

Expected return on assets
(4,056
)
 
(3,762
)
 
—

 
—

Amortization of prior service credit
(1,549
)
 
(1,547
)
 
(858
)
 
(857
)
Amortization of net loss
819

 
1,383

 
135

 
201

Net periodic benefit cost (income)
$
4,010

 
$
5,122

 
$
(108
)
 
$
32