Other Comprehensive Income (Tables)

6 Months Ended

Jun. 30, 2017

Stockholders' Equity Note [Abstract]

Changes in Accumulated Other Comprehensive Loss, Net of Tax

Changes in accumulated other comprehensive loss, net of tax, for the three and six months ended June 30, 2017 and 2016 were as follows:

	Three Months Ended June 30, 2017
(Thousands of Dollars)	Gains and Losses on Cash Flow Hedges			Defined Benefit and Postretirement Items			Total
Accumulated other comprehensive loss at April 1	$	(669	)	$	(597	)	$	(1,266	)
Losses reclassified from net accumulated other comprehensive loss	10			15			25
Net current period other comprehensive income	10			15			25
Accumulated other comprehensive loss at June 30	$	(659	)	$	(582	)	$	(1,241	)

	Three Months Ended June 30, 2016
(Thousands of Dollars)	Gains and Losses on Cash Flow Hedges			Defined Benefit and Postretirement Items			Total
Accumulated other comprehensive loss at April 1	$	(775	)	$	(452	)	$	(1,227	)
Other comprehensive loss before reclassifications	—			11			11
Losses reclassified from net accumulated other comprehensive loss	43			—			43
Net current period other comprehensive income	43			11			54
Accumulated other comprehensive loss at June 30	$	(732	)	$	(441	)	$	(1,173	)

	Six Months Ended June 30, 2017
(Thousands of Dollars)	Gains and Losses on Cash Flow Hedges			Defined Benefit and Postretirement Items			Total
Accumulated other comprehensive loss at Jan. 1	$	(678	)	$	(612	)	$	(1,290	)
Losses reclassified from net accumulated other comprehensive loss	19			30			49
Net current period other comprehensive income	19			30			49
Accumulated other comprehensive loss at June 30	$	(659	)	$	(582	)	$	(1,241	)

	Six Months Ended June 30, 2016
(Thousands of Dollars)	Gains and Losses on Cash Flow Hedges			Defined Benefit and Postretirement Items			Total
Accumulated other comprehensive loss at Jan. 1	$	(817	)	$	(464	)	$	(1,281	)
Other comprehensive loss before reclassifications	—			23			23
Losses reclassified from net accumulated other comprehensive loss	85			—			85
Net current period other comprehensive income	85			23			108
Accumulated other comprehensive loss at June 30	$	(732	)	$	(441	)	$	(1,173	)

Reclassifications out of Accumulated Other Comprehensive Loss

Reclassifications from accumulated other comprehensive loss for the three and six months ended June 30, 2017 and 2016 were as follows:

	Amounts Reclassified from Accumulated Other Comprehensive Loss
(Thousands of Dollars)	Three Months Ended June 30, 2017				Three Months Ended June 30, 2016
Losses on cash flow hedges:
Interest rate derivatives	$	16		(a)	$	67		(a)
Total, pre-tax	16				67
Tax benefit	(6		)		(24		)
Total, net of tax	10				43
Defined benefit pension and postretirement losses:
Amortization of net loss	24			(b)	—			(b)
Total, pre-tax	24				—
Tax benefit	(9		)		—
Total, net of tax	15				—
Total amounts reclassified, net of tax	$	25			$	43

	Amounts Reclassified from Accumulated Other Comprehensive Loss
(Thousands of Dollars)	Six Months Ended June 30, 2017				Six Months Ended June 30, 2016
Losses on cash flow hedges:
Interest rate derivatives	$	31		(a)	$	134		(a)
Total, pre-tax	31				134
Tax benefit	(12		)		(49		)
Total, net of tax	19				85
Defined benefit pension and postretirement losses:
Amortization of net loss	48			(b)	—			(b)
Total, pre-tax	48				—
Tax benefit	(18		)		—
Total, net of tax	30				—
Total amounts reclassified, net of tax	$	49			$	85

^(a)  Included in interest charges.

^(b)  Included in the computation of net periodic pension and postretirement benefit costs. See Note 10 for details regarding these benefit plans.