Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Beginning Balance (in shares) at Dec. 31, 2014		465
Beginning Balance at Dec. 31, 2014	$ 10,741	$ 5	$ (1,837)	$ 11,135	$ (511)	$ 1,949
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	596					596
Other comprehensive income (loss)	(212)				(212)
Exercise of common stock options (in shares)		6
Exercise of common stock options	4			4
Excess tax benefits from stock-based compensation	119			119
Stock-based compensation and issuance of employee benefit plan stock	2,131			2,131
Issuance of common stock for acquisition activity	5			5
Ending Balance (in shares) at Dec. 31, 2015		471
Ending Balance at Dec. 31, 2015	13,384	$ 5	(1,837)	13,394	(723)	2,545
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,371					2,371
Other comprehensive income (loss)	(262)				(262)
Exercise of common stock options (in shares)		6
Exercise of common stock options	1			1
Excess tax benefits from stock-based compensation	829			829
Stock-based compensation and issuance of employee benefit plan stock	2,962			2,962
Ending Balance (in shares) at Dec. 31, 2016		477
Ending Balance at Dec. 31, 2016	19,285	$ 5	(1,837)	17,186	(985)	4,916
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of a change in accounting principle related to stock-based compensation	687					687
Net income	3,033					3,033
Other comprehensive income (loss)	501				501
Exercise of common stock options (in shares)		7
Exercise of common stock options	1			1
Stock-based compensation and issuance of employee benefit plan stock	4,202			4,202
Ending Balance (in shares) at Dec. 31, 2017		484
Ending Balance at Dec. 31, 2017	$ 27,709	$ 5	$ (1,837)	$ 21,389	$ (484)	$ 8,636