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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
	Mar. 31, 2020	Mar. 31, 2019	Jan. 01, 2020	Jan. 01, 2019
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at beginning of period	$ 703	$ 2,225
Net income	31	375
Other comprehensive income	(378)	31
Dividends	(156)	(139)
Share-based compensation plans	(55)	(62)
Purchase of treasury stock	(150)	(828)
Balance at end of period	$ (20)	$ 1,603
Cash dividends (in USD per share)	$ 0.48	$ 0.41
Class A Common Stock
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at beginning of period	$ 5	$ 5
Balance at beginning of period (in shares)	324.0	339.1
Share-based compensation plans (in shares)	1.2	1.7
Purchase of treasury stock (in shares)	(1.0)	(6.7)
Balance at end of period	$ 5	$ 5
Balance at end of period (in shares)	324.2	334.1
Additional Paid-in- Capital
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at beginning of period	$ 5,800	$ 5,814
Share-based compensation plans	(89)	(108)
Balance at end of period	5,711	5,706
Retained Earnings
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at beginning of period	9,644	8,982
Net income	31	375
Dividends	(156)	(139)
Balance at end of period	9,504	9,219
Treasury Stock, at Cost
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at beginning of period	(14,385)	(12,185)
Share-based compensation plans	34	46
Purchase of treasury stock	(150)	(828)
Balance at end of period	(14,501)	(12,967)
Accumulated Other Comprehensive Loss
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Balance at beginning of period	(361)	(391)
Other comprehensive income	(378)	31
Balance at end of period	$ (739)	$ (360)
Adoption of ASU 2016-13
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU			$ (15)
Adoption of ASU 2016-13 \| Class A Common Stock
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU			0
Adoption of ASU 2016-13 \| Additional Paid-in- Capital
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU			0
Adoption of ASU 2016-13 \| Retained Earnings
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU			(15)
Adoption of ASU 2016-13 \| Treasury Stock, at Cost
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU			0
Adoption of ASU 2016-13 \| Accumulated Other Comprehensive Loss
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU			$ 0
Adoption of ASU 2016-02
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU				$ 1
Adoption of ASU 2016-02 \| Class A Common Stock
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU				0
Adoption of ASU 2016-02 \| Additional Paid-in- Capital
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU				0
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(Increase) Decrease in Shareholders' Deficit [Roll Forward]
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(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU				0
Adoption of ASU 2016-02 \| Accumulated Other Comprehensive Loss
(Increase) Decrease in Shareholders' Deficit [Roll Forward]
Adoption of ASU				$ 0