Accumulated Other Comprehensive Income (Tables)

12 Months Ended

Dec. 31, 2017

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

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

The following tables provide the components of accumulated other comprehensive income / (loss) (AOCI) by component (in millions):



	Pension and Retiree Health and Welfare Benefit Items^a			Equity Method Investments			Total
Balance at December 31, 2016	$	122		$	(3	)	$	119
Other comprehensive income (loss) before reclassifications	114			—			114
Amounts reclassified from AOCI	(2		)	—			(2		)
Balance at December 31, 2017	$	234		$	(3	)	$	231

Balance at December 31, 2015	$	50		$	(2	)	$	48
Other comprehensive income (loss) before reclassifications	73			(1		)	72
Amounts reclassified from AOCI	(1		)	—			(1		)
Balance at December 31, 2016	$	122		$	(3	)	$	119

^a Amounts are net of tax. See Note 13 to the Consolidated Financial Statements for additional details.

Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]



Reclassifications out of AOCI^b
	Year Ended		Year Ended
Details about AOCI Components	December 31, 2017		December 31, 2016			Income Statement Line Item
Amortization of pension and retiree health and welfare benefit items
Actuarial losses	$	—	$	(1	)	^c
Prior service credits	2		3			^c
	2		2			Total before tax
	—		(1		)	Tax (expense) / benefit
Total reclassifications for the period	$	2	$	1		Net of tax

^b Amounts in parenthesis indicate debits to the income statement.

^c This accumulated other comprehensive income component is included in the computation of net periodic pension and retiree health and welfare cost (see Note 13 to the Consolidated Financial Statements for additional details).