Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Number of shares of common stock [Member]	Common stock and additional paid-in capital [Member]	Accumulated deficit [Member]	Accumulated other comprehensive (loss) [Member]
Beginning Balance, Shares at Dec. 31, 2014		760.4
Beginning Balance at Dec. 31, 2014	$ 25,778		$ 30,410	$ (4,624)	$ (8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	6,939			6,939
Other comprehensive income (loss), net of tax	(472)				(472)
Dividends	(2,548)			(2,548)
Issuance of common stock in connection with the Company’s equity award programs, Shares		5.6
Issuance of common stock in connection with the Company’s equity award programs	82		82
Stock-based compensation expense	319		319
Tax impact related to employee stock-based compensation expense	(162)		(162)
Repurchases of common stock, Shares		(12.0)
Repurchases of common stock	(1,853)			(1,853)
Ending Balance, Shares at Dec. 31, 2015		754.0
Ending Balance at Dec. 31, 2015	28,083		30,649	(2,086)	(480)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	7,722			7,722
Other comprehensive income (loss), net of tax	9				9
Dividends	(3,120)			(3,120)
Issuance of common stock in connection with the Company’s equity award programs, Shares		3.9
Issuance of common stock in connection with the Company’s equity award programs	55		55
Stock-based compensation expense	342		342
Tax impact related to employee stock-based compensation expense	(189)		(262)	73
Repurchases of common stock, Shares		(19.7)
Repurchases of common stock	$ (3,027)			(3,027)
Ending Balance, Shares at Dec. 31, 2016	738.2	738.2
Ending Balance at Dec. 31, 2016	$ 29,875		30,784	(438)	(471)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,979			1,979
Other comprehensive income (loss), net of tax	(208)				(208)
Dividends	(3,487)			(3,487)
Issuance of common stock in connection with the Company’s equity award programs, Shares		2.5
Issuance of common stock in connection with the Company’s equity award programs	52		52
Stock-based compensation expense	347		347
Tax impact related to employee stock-based compensation expense	(191)		(191)	0
Repurchases of common stock, Shares		(18.5)
Repurchases of common stock	$ (3,126)			(3,126)
Ending Balance, Shares at Dec. 31, 2017	722.2	722.2
Ending Balance at Dec. 31, 2017	$ 25,241		$ 30,992	$ (5,072)	$ (679)