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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash, stock and payment-in-kind (PIK).

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

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Gross number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP). Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

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Amount of stockholders' equity including the portion attributable to noncontrolling interests, after the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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Number of shares that have been repurchased during the period and are being held in treasury.

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Millions	Total	Common shares [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Treasury shares [Member]	AOCI Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting policies \| Accounting Standards Update 2014-09 [Member]	$ (3)			$ (3)
Beginning balance, restated	6,289	$ 3	$ 7,765	10,348	$ (12,027)	$ 200
Beginning balance (in shares) at Dec. 31, 2016		154,759,904
Beginning balance at Dec. 31, 2016	6,292	$ 3	7,765	10,351	(12,027)	200
Comprehensive income (loss) [Abstract]
Net income	1,303			1,303
Other comprehensive income (loss), net of tax	112					112
Total comprehensive income	1,415
Dividends to shareholders	(379)			(379)
Repurchase of common shares (in shares)		(10,184,145)
Repurchase of common shares	(1,323)				(1,323)
Share-based compensation plans (in shares)		3,761,769
Share-based compensation plans	304		252		52
Ending balance (in shares) at Sep. 30, 2017		148,337,528
Ending balance at Sep. 30, 2017	6,306	$ 3	8,017	11,272	(13,298)	312
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting policies \| Cumulative effect of change in accounting policies - Recognition and measurement of financial instruments						1
Beginning balance (in shares) at Dec. 31, 2017		146,634,664
Beginning balance at Dec. 31, 2017	5,995	$ 3	8,085	11,326	(13,648)	229
Comprehensive income (loss) [Abstract]
Net income	1,559			1,559
Other comprehensive income (loss), net of tax	(472)					(472)
Total comprehensive income	1,087
Dividends to shareholders	(388)			(388)
Repurchase of common shares (in shares)		(8,526,715)
Repurchase of common shares	(1,265)				(1,265)
Share-based compensation plans (in shares)		1,711,676
Share-based compensation plans	189		129		60
Ending balance (in shares) at Sep. 30, 2018		139,819,625
Ending balance at Sep. 30, 2018	5,618	$ 3	$ 8,214	12,498	$ (14,853)	(244)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting policies \| Cumulative effect of change in accounting policies - Recognition and measurement of financial instruments	$ 0			$ 1		$ (1)