A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
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- Definition

Amount after tax of other comprehensive income (loss) attributable to parent entity.

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- Definition

Amount after tax of reclassification adjustments of other comprehensive income (loss) attributable to parent.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

+ References

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Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	$ 23,491	$ 13,399	$ 14,060
Accumulated other comprehensive income (loss) by component
Other comprehensive income (loss) before reclassifications	(16)	(296)
Amounts reclassified from accumulated other comprehensive income	138	113
Net current-period other comprehensive income (loss)	122	(183)	83
Defined Benefit Plans
Accumulated other comprehensive income (loss) by component
Amounts reclassified from accumulated other comprehensive income	138	113
Defined Benefit Plans \| Pension plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	(1,731)	(1,895)	(1,715)
Accumulated other comprehensive income (loss) by component
Other comprehensive income (loss) before reclassifications	39	(280)
Amounts reclassified from accumulated other comprehensive income	125	100
Net current-period other comprehensive income (loss)	164	(180)
Defined Benefit Plans \| Post-Retirement benefit plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	(235)	(162)	(180)
Accumulated other comprehensive income (loss) by component
Other comprehensive income (loss) before reclassifications	(86)	6
Amounts reclassified from accumulated other comprehensive income	13	12
Net current-period other comprehensive income (loss)	(73)	18
Foreign Currency Translation Adjustment and Other
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	(29)	(60)	(39)
Accumulated other comprehensive income (loss) by component
Other comprehensive income (loss) before reclassifications	31	(22)
Amounts reclassified from accumulated other comprehensive income	0	1
Net current-period other comprehensive income (loss)	31	(21)
AOCI Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' Equity Attributable to Parent	(1,995)	(2,117)	(1,934)	$ (2,017)
Accumulated other comprehensive income (loss) by component
Net current-period other comprehensive income (loss)	$ 122	$ (183)	$ 83