ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Notes)
 6 Months Ended
Jun. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]  
Comprehensive Income (Loss) Note [Text Block]
ACCUMULATED OTHER COMPREHENSIVE LOSS

The following table sets forth the effect of reclassifications from accumulated other comprehensive loss in our consolidated statements of income for the periods indicated:
 
 
Three Months Ended
 
Six Months Ended
 
Affected Line Item in the
Details About Accumulated Other
 
June 30,
 
June 30,
 
Consolidated Statements
Comprehensive Loss Components
 
2020
2019
 
2020
2019
 
of Income
 
 
(Thousands of dollars)
 
 
Pension and other postemployment benefit plan obligations (a)
 
 
 
 
 
 
 
 
Amortization of net loss
 
$
10,623

$
8,821

 
$
21,246

$
17,642

 
 
Amortization of unrecognized prior service credit
 
(29
)
(168
)
 
(58
)
(336
)
 
 
 
 
10,594

8,653

 
21,188

17,306

 
 
Reclassification of stranded tax effects (b)
 
—

—

 
—

(1,218
)
 
 
Regulatory adjustments (c)
 
(10,296
)
(8,440
)
 
(20,592
)
(15,662
)
 
 
 
 
298

213

 
596

426

 
Income before income taxes
 
 
(75
)
(53
)
 
(149
)
(106
)
 
Income tax expense
Total reclassifications for the period
 
$
223

$
160

 
$
447

$
320

 
Net income
(a) These components of accumulated other comprehensive loss are included in the computation of net periodic benefit cost. See Note 10 for additional detail of our net periodic benefit cost.
(b) Reflects the impact of the adoption of ASU 2018-02 in fiscal year 2019 related to stranded tax effects in accumulated other comprehensive income as a result of the Tax Cuts and Jobs Act of 2017. See Note 1 for additional information regarding our adoption of this standard.
(c) Regulatory adjustments represent pension and other postemployment benefit costs expected to be recovered through rates and are deferred as part of our regulatory assets. See Note 3 for additional disclosures of regulatory assets and liabilities.