Other Comprehensive Income (Tables)

6 Months Ended

Jun. 30, 2018

Stockholders' Equity Note [Abstract]

Changes in Accumulated Other Comprehensive Income (Loss), Net of Tax

Changes in accumulated other comprehensive loss, net of tax, for the three and six months ended June 30, 2018 and 2017 were as follows:

	Three Months Ended June 30, 2018
(Millions of Dollars)	Gains and Losses on Cash Flow Hedges			Defined Benefit Pension and Postretirement Items			Total
Accumulated other comprehensive loss at April 1	$	(58	)	$	(66	)	$	(124	)
Losses reclassified from net accumulated other comprehensive loss	1			1			2
Net current period other comprehensive income	1			1			2
Accumulated other comprehensive loss at June 30	$	(57	)	$	(65	)	$	(122	)

	Three Months Ended June 30, 2017
(Millions of Dollars)	Gains and Losses on Cash Flow Hedges			Defined Benefit Pension and Postretirement Items			Total
Accumulated other comprehensive loss at April 1	$	(51	)	$	(58	)	$	(109	)
Losses reclassified from net accumulated other comprehensive loss	1			1			2
Net current period other comprehensive income	1			1			2
Accumulated other comprehensive loss at June 30	$	(50	)	$	(57	)	$	(107	)

	Six Months Ended June 30, 2018
(Millions of Dollars)	Gains and Losses on Cash Flow Hedges			Defined Benefit Pension and Postretirement Items			Total
Accumulated other comprehensive loss at Jan. 1	$	(58	)	$	(67	)	$	(125	)
Losses reclassified from net accumulated other comprehensive loss	1			2			3
Net current period other comprehensive income	1			2			3
Accumulated other comprehensive loss at June 30	$	(57	)	$	(65	)	$	(122	)

	Six Months Ended June 30, 2017
(Millions of Dollars)	Gains and Losses on Cash Flow Hedges			Defined Benefit Pension and Postretirement Items			Total
Accumulated other comprehensive loss at Jan. 1	$	(51	)	$	(59	)	$	(110	)
Losses reclassified from net accumulated other comprehensive loss	1			2			3
Net current period other comprehensive income	1			2			3
Accumulated other comprehensive loss at June 30	$	(50	)	$	(57	)	$	(107	)

Reclassifications out of Accumulated Other Comprehensive Loss

Reclassifications from accumulated other comprehensive loss for the three and six months ended June 30, 2018 and 2017 were as follows:

	Amounts Reclassifiedfrom Accumulated Other ComprehensiveLoss
(Millions of Dollars)	Three Months Ended June 30, 2018				Three Months Ended June 30, 2017
Losses on cash flow hedges:
Interest rate derivatives	$	1		(a)	$	2		(a)
Total, pre-tax	1				2
Tax benefit	—				(1		)
Total, net of tax	1				1
Defined benefit pension and postretirement losses:
Amortization of net loss	2			(b)	2			(b)
Total, pre-tax	2				2
Tax benefit	(1		)		(1		)
Total, net of tax	1				1
Total amounts reclassified, net of tax	$	2			$	2

	Amounts Reclassifiedfrom Accumulated Other ComprehensiveLoss
(Millions of Dollars)	Six Months Ended June 30, 2018				Six Months Ended June 30, 2017
Losses on cash flow hedges:
Interest rate derivatives	$	1		(a)	$	2		(a)
Total, pre-tax	1				2
Tax benefit	—				(1		)
Total, net of tax	1				1
Defined benefit pension and postretirement losses:
Amortization of net loss	3			(b)	3			(b)
Total, pre-tax	3				3
Tax benefit	(1		)		(1		)
Total, net of tax	2				2
Total amounts reclassified, net of tax	$	3			$	3

^(a)  Included in interest charges

^(b)  Included in the computation of net periodic pension and postretirement benefit costs. See Note 12 to the consolidated financial statements for details regarding these benefit plans.