Consolidated Statements of Changes in Equity, Accumulated Other Comprehensive Income (Loss) and Redeemable Non-Controlling Interest - USD ($) $ in Millions	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non- Controlling Interest in Consolidated Subsidiaries	Redeemable Non-controlling Interest
Beginning balance (in shares) at Dec. 31, 2015		628,000,000	34,000,000
Beginning balance at Dec. 31, 2015	$ 14,853	$ 6	$ (1,448)	$ 12,290	$ 4,161	$ (188)	$ 32	$ 35
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss)	$ (156)					(156)
Exercise of common stock options (in shares)	746,000	1,000,000
Exercise of common stock options	$ 22			22
Treasury shares retired in connection with stock split (in shares)		35,000,000	35,000,000
Treasury shares retired in connection with stock split	$ 0		$ 1,512	(1,142)	(370)
Repurchases of common stock (in shares)	(900,000)		(1,000,000)
Repurchases of common stock	$ (50)		$ (50)
Payments relating to treasury shares (in shares)	(1,100,000)		(1,000,000)
Payments relating to treasury shares	$ (54)		$ (54)
Stock-based compensation	136			136
Issuance of restricted stock (in shares)		2,000,000
Adjustment to redemption value	(2)				(2)			1
Distributions of profits	(19)						(19)	(3)
Dividends paid to stockholders	(409)				(409)
Net income attributable to non-controlling interest	(3)				(27)		24	3
Net income	1,457				1,457
Ending balance (in shares) at Dec. 31, 2016		596,000,000	1,000,000
Ending balance at Dec. 31, 2016	15,775	$ 6	$ (40)	11,306	4,810	(344)	37	36
Accumulated other comprehensive loss was as follows:
Foreign currency translation adjustments	(345)
Fair value of available-for-sale securities	108
Comprehensive income from equity method investment	2
Employee benefit plans adjustments	(109)
Accumulated other comprehensive loss	(344)
Other comprehensive income (loss)	$ 121					121
Exercise of common stock options (in shares)	597,000
Exercise of common stock options	$ 17			17
Repurchases of common stock (in shares)	(15,000,000)		(15,000,000)
Repurchases of common stock	$ (949)		$ (949)
Payments relating to treasury shares (in shares)	(1,500,000)		(1,000,000)
Payments relating to treasury shares	$ (88)		$ (88)
Stock-based compensation	152			152
Issuance of restricted stock (in shares)		4,000,000
Issuance of restricted stock	0		$ 1	(1)
Changes in non-controlling interest	(92)			(82)			(10)
Distributions of profits	(26)						(26)
Dividends paid to stockholders	(476)				(476)
Redeemable non-controlling interest	(2)				(2)			(37)
Net income attributable to non-controlling interest	(1)				(28)		27	1
Net income	$ 2,554				2,554
Ending balance (in shares) at Dec. 31, 2017	600,000,000	600,000,000	17,000,000
Ending balance at Dec. 31, 2017	$ 16,985	$ 6	$ (1,076)	11,392	6,858	(223)	28	0
Accumulated other comprehensive loss was as follows:
Foreign currency translation adjustments	(136)
Fair value of available-for-sale securities	0
Comprehensive income from equity method investment	2
Employee benefit plans adjustments	(89)
Accumulated other comprehensive loss	(223)
Other comprehensive income (loss)	(92)
Other comprehensive loss	$ (66)					(66)
Exercise of common stock options (in shares)	908,000	1,000,000
Exercise of common stock options	$ 32			32
Repurchases of common stock (in shares)	(16,300,000)		(16,000,000)
Repurchases of common stock	$ (1,198)		$ (1,198)
Payments relating to treasury shares (in shares)	(1,500,000)		(2,000,000)
Payments relating to treasury shares	$ (80)		$ (80)
Stock-based compensation	146			146
Issuance of restricted stock (in shares)		3,000,000
Changes in non-controlling interest	(25)			(23)	0		(2)
Distributions of profits	(28)						(28)
Dividends paid to stockholders	(555)				(555)
Redeemable non-controlling interest								71
Impact of adoption of ASU 2018-02 to reclassify items stranded in other comprehensive income	26				26	(26)
Net income attributable to non-controlling interest	0				(32)		32
Net income	$ 2,020				2,020
Ending balance (in shares) at Dec. 31, 2018	604,000,000	604,000,000	35,000,000
Ending balance at Dec. 31, 2018	$ 17,231	$ 6	$ (2,354)	$ 11,547	$ 8,317	$ (315)	$ 30	$ 71
Accumulated other comprehensive loss was as follows:
Foreign currency translation adjustments	(227)
Fair value of available-for-sale securities	0
Comprehensive income from equity method investment	2
Employee benefit plans adjustments	(90)
Accumulated other comprehensive loss	$ (315)