Consolidated Statement of Stockholders' Equity - USD ($) $ in Millions		Total	Preferred Stock Outstanding	Common Stock Outstanding	Treasury Shares at Cost	Par Value and Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance, beginning of period at Dec. 31, 2016		$ 18,236			$ (1)	$ 38,846	$ 1	$ (20,610)
Common stock outstanding, beginning balance (in shares) at Dec. 31, 2016				826,357,331
Preferred stock outstanding, beginning balance (in shares) at Dec. 31, 2016			20,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		4,536						4,536
Other comprehensive (loss) income		7					7
Stock-based compensation		344				344
Exercise of stock options		19				19
Exercise of stock options (in shares)				450,493
Stock issued for employee stock purchase plan		82				82
Stock issued for employee stock purchase plan (in shares)				1,832,043
Issuance of vested restricted stock units (in shares)				8,338,271
Shares withheld related to net share settlement of stock awards and stock options		(166)				(166)
Shares withheld related to net share settlement of stock awards and stock options (in shares)				(2,754,721)
Mandatory conversion of preferred shares to common shares			(20,000,000)	32,237,983
Repurchases of common stock		$ (444)				(444)
Repurchases of common stock (in shares)		(7,010,889)		(7,010,889)
Transfer RSU from NQDC plan					(3)	3
Transfer RSU to NQDC plan (in shares)				(43,860)
Dividends on preferred stock		$ (55)				(55)
Preferred stock outstanding, ending balance (in shares) at Dec. 31, 2017			0
Balance, end of period at Dec. 31, 2017		22,559			(4)	38,629	8	(16,074)
Common stock outstanding, ending balance (in shares) at Dec. 31, 2017				859,406,651
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		2,888						2,888
Other comprehensive (loss) income		(332)					(332)
Stock-based compensation		473				473
Exercise of stock options		3				3
Exercise of stock options (in shares)				187,965
Stock issued for employee stock purchase plan		103				103
Stock issued for employee stock purchase plan (in shares)				2,011,794
Issuance of vested restricted stock units (in shares)				7,448,148
Issuance of restricted stock awards (in shares)				225,799
Shares withheld related to net share settlement of stock awards and stock options		(146)				(146)
Shares withheld related to net share settlement of stock awards and stock options (in shares)				(2,321,827)
Repurchases of common stock		$ (1,054)				(1,054)
Repurchases of common stock (in shares)		(16,738,758)		(16,738,758)
Transfer RSU from NQDC plan					(2)	2
Transfer RSU to NQDC plan (in shares)				(39,455)
Prior year Retained Earnings	[1]	$ 224					(8)	232
Preferred stock outstanding, ending balance (in shares) at Dec. 31, 2018			0
Balance, end of period at Dec. 31, 2018		$ 24,718			(6)	38,010	(332)	(12,954)
Common stock outstanding, ending balance (in shares) at Dec. 31, 2018		850,180,317		850,180,317
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		$ 3,468						3,468
Other comprehensive (loss) income		(536)					(536)
Stock-based compensation		517				517
Exercise of stock options		1				1
Exercise of stock options (in shares)				85,083
Stock issued for employee stock purchase plan		124				124
Stock issued for employee stock purchase plan (in shares)				2,091,650
Issuance of vested restricted stock units (in shares)				6,685,950
Forfeiture of restricted stock awards (in shares)				(24,682)
Shares withheld related to net share settlement of stock awards and stock options		(156)				(156)
Shares withheld related to net share settlement of stock awards and stock options (in shares)				(2,094,555)
Transfer RSU from NQDC plan					(2)	2
Transfer RSU to NQDC plan (in shares)				(18,363)
Prior year Retained Earnings	[1]	653						653
Preferred stock outstanding, ending balance (in shares) at Dec. 31, 2019			0
Balance, end of period at Dec. 31, 2019		$ 28,789			$ (8)	$ 38,498	$ (868)	$ (8,833)
Common stock outstanding, ending balance (in shares) at Dec. 31, 2019		856,905,400		856,905,400

[1] Prior year Retained Earnings represents the impact of the adoption of new accounting standards on beginning Accumulated Deficit and Accumulated Other Comprehensive Loss. See Note 1 – Summary of Significant Accounting Policies for further information.