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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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Accumulated Other Comprehensive Loss and Shareholders' Equity - Changes in Shareholders' Equity (Deficit) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jan. 01, 2018	Dec. 31, 2017	Jan. 01, 2016
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at beginning of period			$ 3,731
Balance at beginning of period (in shares)			359.1
Balance at beginning of period (as adjusted)	$ 2,841		$ 2,841			$ 3,582
Net income	610	$ 489	1,008	$ 860
Other comprehensive income	(385)	156	(223)	341
Dividends ($0.74 per share)			(263)
Share-based compensation plans			$ (3)
Share-based compensation plans (in shares)			1.4
Purchase of treasury stock			$ (1,632)
Purchase of treasury stock (in shares)			(11.8)
Balance at end of period	$ 2,841		$ 2,841
Balance at end of period (in shares)	348.7		348.7
Cash dividends (in USD per share)			$ 0.74
Class A Common Stock
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at beginning of period			$ 5
Balance at beginning of period (as adjusted)						5
Balance at end of period	$ 5		5
Additional Paid-in- Capital
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at beginning of period			5,770
Balance at beginning of period (as adjusted)						5,770
Share-based compensation plans			(42)
Balance at end of period	5,728		5,728
Retained Earnings
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at beginning of period			7,391
Balance at beginning of period (as adjusted)						7,242
Net income			1,008
Dividends ($0.74 per share)			(263)
Balance at end of period	8,363		8,363
Treasury Stock, at Cost
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at beginning of period			(9,418)
Balance at beginning of period (as adjusted)						(9,418)
Share-based compensation plans			39
Purchase of treasury stock			(1,632)
Balance at end of period	(11,011)		(11,011)
Accumulated Other Comprehensive Loss
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at beginning of period			(17)	(497)
Balance at beginning of period (as adjusted)						(17)
Other comprehensive income			(223)
Balance at end of period	$ (244)	$ (156)	$ (244)	$ (156)
Adoption of ASU 2014-09
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU 2014-09						(149)
Adoption of ASU 2014-09 \| Retained Earnings
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU 2014-09						(149)	$ 264
Adoption of ASU 2014-09 \| Accumulated Other Comprehensive Loss
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU 2014-09						$ 0
Adoption of ASU 2016-01
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU 2014-09					$ 0
Adoption of ASU 2016-01 \| Retained Earnings
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU 2014-09					4
Adoption of ASU 2016-01 \| Accumulated Other Comprehensive Loss
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU 2014-09					(4)
Adoption of ASU 2016-16
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU 2014-09					372
Adoption of ASU 2016-16 \| Retained Earnings
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU 2014-09					$ 372