Other Comprehensive Income (Tables)

12 Months Ended

Dec. 31, 2020

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 years ended Dec. 31:

	2020
(Millions of Dollars)	Gains and Losses on Cash Flow Hedges			Defined Benefit Pension and Postretirement Items			Total
Accumulated other comprehensive loss at Jan. 1	$	(24)		$	(3)		$	(27)
Losses reclassified from net accumulated other comprehensive loss:
Interest rate derivatives (net of taxes of $— and $—, respectively)	1		(a)	—			1
Amortization of net actuarial loss (net of taxes of $— and $1, respectively)	—			2		(b)	2
Net current period other comprehensive income (loss)	1			2			3
Accumulated other comprehensive loss at Dec. 31	$	(23)		$	(1)		$	(24)

(a)Included in interest charges.

(b)Included in the computation of net periodic pension and postretirement benefit costs. See Note 9 for further information.

	2019
(Millions of Dollars)	Gains and Losses on Cash Flow Hedges			Defined Benefit Pension and Postretirement Items			Total
Accumulated other comprehensive loss at Jan. 1	$	(26)		$	—		$	(26)
Losses (gains) reclassified from net accumulated other comprehensive loss:
Interest rate derivatives (net of taxes of $— and $—, respectively)	2		(a)	—			2
Amortization of net actuarial gains (net of taxes of $— and $(1), respectively)	—			(3)		(b)	(3)
Net current period other comprehensive income	2			(3)			(1)
Accumulated other comprehensive loss at Dec. 31	$	(24)		$	(3)		$	(27)

(a)Included in interest charges.

(b)Included in the computation of net periodic pension and postretirement benefit costs. See Note 9 for further information.