Accumulated Other Comprehensive Income (Tables)

9 Months Ended

Sep. 30, 2020

Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]

Schedule of Accumulated Other Comprehensive Income (Loss)

The following table provides the components of accumulated other comprehensive income (loss) (AOCI) by component (in millions):

	Pension and Retiree Health and Welfare Benefit Items		Equity Method Investments		Accumulated Other Comprehensive Income (Loss)
Balance as of December 31, 2018	$	133	$	(3)	$	130
Other comprehensive income (loss), net before reclassifications	66		(1)		65
Amounts reclassified from AOCI:
Amortization of net gaina	(1)		—		(1)
Amortization of prior service creditsa	(3)		—		(3)
Tax expense (benefit)	1		—		1
Balance as of September 30, 2019	$	196	$	(4)	$	192
Balance as of December 31, 2019	$	149	$	(4)	$	145
Other comprehensive income (loss), net before reclassifications	—		1		1
Amounts reclassified from AOCI:
Amortization of net gaina	1		—		1
Balance as of September 30, 2020	$	150	$	(3)	$	147

a     This accumulated other comprehensive income component is included in the computation of net periodic pension cost (see Note 6 for additional details).