Condensed Consolidated Statement of Stockholders' Equity Statement - USD ($) $ in Millions	Total	Treasury stock	Accumulated other comprehensive income (loss)	Retained earnings	Capital in excess of par value	Common Stock
Balance at beginning of period at Dec. 31, 2017	$ 9,641	$ (6,462)	$ 12	$ 13,832	$ 1,451	$ 808
Balance at beginning of period (Accounting Standards Update 2017-12) at Dec. 31, 2017	9,641	(6,462)	(6)	13,850	1,451	808
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of common stock	(500)	500	0	0	0	0
Issuance of common and treasury stock pursuant to Employee stock plans	4	5	0	0	(9)	0
Share-based compensation	10	0	0	0	10	0
Cash dividends	(75)	0	0	75	0	0
Comprehensive income	547	0	84	463	0	0
Balance at end of period at Mar. 31, 2018	9,619	(6,957)	78	14,238	1,452	808
Balance at beginning of period at Dec. 31, 2017	9,641	(6,462)	12	13,832	1,451	808
Balance at beginning of period (Accounting Standards Update 2017-12) at Dec. 31, 2017	9,641	(6,462)	(6)	13,850	1,451	808
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	1,499
Balance at end of period at Jun. 30, 2018	9,997	(7,456)	298	14,878	1,469	808
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of new accounting standards	0	0	(18)	18	0	0
Balance at beginning of period at Mar. 31, 2018	9,619	(6,957)	78	14,238	1,452	808
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of common stock	(500)	500	0	0	0	0
Issuance of common and treasury stock pursuant to Employee stock plans	9	1	0	0	8	0
Share-based compensation	9	0	0	0	9	0
Cash dividends	(93)	0	0	93	0	0
Comprehensive income	953	0	220	733	0	0
Balance at end of period at Jun. 30, 2018	9,997	(7,456)	298	14,878	1,469	808
Balance at beginning of period at Dec. 31, 2018	9,853	(8,452)	20	15,967	1,510	808
Balance at beginning of period (Accounting Standards Update 2016-02) at Dec. 31, 2018	9,908	(8,452)	20	16,022	1,510	808
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of common stock	(500)	500	0	0	0	0
Issuance of common and treasury stock pursuant to Employee stock plans	4	6	0	0	10	0
Share-based compensation	13	0	0	0	13	0
Cash dividends	(89)	0	0	89	0	0
Comprehensive income	463	0	76	387	0	0
Balance at end of period at Mar. 31, 2019	9,791	(8,946)	96	16,320	1,513	808
Balance at beginning of period at Dec. 31, 2018	9,853	(8,452)	20	15,967	1,510	808
Balance at beginning of period (Accounting Standards Update 2016-02) at Dec. 31, 2018	9,908	(8,452)	20	16,022	1,510	808
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	1,138
Balance at end of period at Jun. 30, 2019	9,940	(9,394)	30	16,962	1,534	808
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of new accounting standards	55	0	0	55	0	0
Balance at beginning of period at Mar. 31, 2019	9,791	(8,946)	96	16,320	1,513	808
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of common stock	(450)	(450)	0	0	0	0
Issuance of common and treasury stock pursuant to Employee stock plans	10	2	0	0	8	0
Share-based compensation	13	0	0	0	13	0
Cash dividends	(99)	0	0	(99)	0	0
Comprehensive income	675	0	(66)	741	0	0
Balance at end of period at Jun. 30, 2019	$ 9,940	$ (9,394)	$ 30	$ 16,962	$ 1,534	$ 808