Other Comprehensive Income (Tables)

9 Months Ended

Sep. 30, 2021

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 nine months ended Sept. 30, 2021 and 2020:

	Three Months Ended Sept. 30, 2021						Three Months Ended Sept. 30, 2020
(Millions of Dollars)	Gains and Losses on Cash Flow Hedges		Defined Benefit Pension and Postretirement Items		Total		Gains and Losses on Cash Flow Hedges		Defined Benefit Pension and Postretirement Items		Total
Accumulated other comprehensive loss at July 1	$	(22)	$	(1)	$	(23)	$	(24)	$	(2)	$	(26)
Losses reclassified from net accumulated other comprehensive loss:
Interest rate derivatives (net of taxes of $—, $—, $— and $—, respectively) (a)	—		—		—		—		—		—
Net current period other comprehensive income	—		—		—		—		—		—
Accumulated other comprehensive loss at Sept. 30	$	(22)	$	(1)	$	(23)	$	(24)	$	(2)	$	(26)

(a) Included in interest charges.

	Nine Months Ended Sept. 30, 2021						Nine Months Ended Sept. 30, 2020
(Millions of Dollars)	Gains and Losses on Cash Flow Hedges		Defined Benefit Pension and Postretirement Items		Total		Gains and Losses on Cash Flow Hedges		Defined Benefit Pension and Postretirement Items		Total
Accumulated other comprehensive loss at Jan. 1	$	(23)	$	(1)	$	(24)	$	(25)	$	(2)	$	(27)
Losses reclassified from net accumulated other comprehensive loss:
Interest rate derivatives (net of taxes of $—, $—, $— and $—, respectively) (a)	1		—		1		1		—		1
Net current period other comprehensive income	1		—		1		1		—		1
Accumulated other comprehensive loss at Sept. 30	$	(22)	$	(1)	$	(23)	$	(24)	$	(2)	$	(26)

(a) Included in interest charges