Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Millions		Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital Common [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Parent [Member]	Non-controlling Interests [Member]	Total
Balance at Dec. 31, 2015		$ 2,300	$ 840	$ 13,352	$ 13,832	$ (9,725)	$ (1,811)	$ 18,788	$ 75	$ 18,863
Net (loss) income					3,695			3,695	10	3,705
Other comprehensive income (loss)							135	135	(6)	129
Purchase of common stock for treasury				165		(4,409)		(4,244)		(4,244)
Shares issued to benefit plans and for option exercises			6	178		(2)		182		182
Dividends on shares					(647)			(647)		(647)
Other, net						(16)		(16)	(12)	(28)
Balance at Dec. 31, 2016		2,300	846	13,695	16,880	(14,152)	(1,676)	17,893	67	17,960
Net (loss) income					(497)			(497)	18	(479)
Other comprehensive income (loss)							834	834	6	840
Purchase of common stock for treasury				14		(2,462)		(2,448)		(2,448)
Shares issued to benefit plans and for option exercises			8	349		(2)		355		355
Dividends on shares					(654)			(654)		(654)
Other, net | Accounting Standards Update 2016-09 [Member]					233
Other, net	[1]			31	201	(17)		215	(19)	196
Balance at Dec. 31, 2017		2,300	854	14,089	15,930	(16,633)	(842)	15,698	72	15,770
Net (loss) income					1,066			1,066	24	1,090
Other comprehensive income (loss)							(168)	(168)	(1)	(169)
Purchase of common stock for treasury						(2,230)		(2,230)		(2,230)
Shares issued to benefit plans and for option exercises			3	123				126		126
Dividends on shares					(688)			(688)		(688)
Other, net					(5)	(7)		(12)	(1)	(13)
Balance at Dec. 31, 2018		$ 2,300	$ 857	$ 14,212	$ 16,303	$ (18,870)	$ (1,010)	$ 13,792	$ 94	$ 13,886

[1] Adjustment to retained earnings includes the cumulative effect of the accounting change we recorded upon adoption of ASU 2016-09 in 2017 in the amount of $233 million.