Accumulated Other Comprehensive Income (Tables)

9 Months Ended

Sep. 30, 2019

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 at 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 at September 30, 2019	$	196		$	(4	)	$	192
Balance at December 31, 2017	$	234		$	(3	)	$	231
Other comprehensive income (loss), net before reclassifications	—			1			1
Amounts reclassified from AOCI:
Reclassification due to ASU 2016-01 adoption	—			(1		)	(1		)
Reclassification due to ASU 2018-02 adoption	26			—			26
Amortization of prior service creditsa	(2		)	—			(2		)
Tax expense (benefit)	1			—			1
Balance at September 30, 2018	$	259		$	(3	)	$	256

^a This accumulated other comprehensive income component is included in the computation of net periodic pension and retiree health and welfare cost (see Note 7 for additional details).