v3.5.0.2
EMPLOYEE BENEFIT PLANS (Tables)
 6 Months Ended
Jun. 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 June 30:
 
 
 
 
 
 
 
Service cost
$
1,926

 
$
1,919

 
$
105

 
$
118

Interest cost
1,006

 
1,097

 
100

 
111

Expected return on assets
(1,351
)
 
(1,254
)
 
—

 
—

Amortization of prior service credit
(516
)
 
(515
)
 
(286
)
 
(286
)
Amortization of net loss
273

 
461

 
45

 
67

Net periodic benefit cost (income)
$
1,338

 
$
1,708

 
$
(36
)
 
$
10

 
 
 
 
 
 
 
 
For the six months ended June 30:
 
 
 
 
 
 
 
Service cost
$
3,852

 
$
3,838

 
$
210

 
$
236

Interest cost
2,012

 
2,194

 
200

 
223

Expected return on assets
(2,703
)
 
(2,508
)
 
—

 
—

Amortization of prior service credit
(1,033
)
 
(1,031
)
 
(572
)
 
(572
)
Amortization of net loss
546

 
922

 
90

 
134

Net periodic benefit cost (income)
$
2,674

 
$
3,415

 
$
(72
)
 
$
21