CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common stock	Additional paid-in capital	Treasury stock at cost	Retained earnings	Accumulated other comprehensive income
Beginning balance at Dec. 31, 2017		$ 2	$ 15,293	$ (21,892)	$ 13,929	$ 717
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued		0
Common stock repurchased/forfeited		0
Common stock and stock-based awards issued			70
Tax withholdings related to net share settlements of restricted stock units and awards			(189)
Stock-based compensation			396
Other			1
Common stock repurchased				(3,001)
Net income	$ 1,770				1,770
Dividends and dividend equivalents declared					0
Other					0
Foreign currency translation adjustment						(218)
Change in unrealized gains (losses) on investments	(30)					(30)
Change in unrealized gains (losses) on derivative instruments						92
Tax benefit (provision) on above items						(11)
Ending balance at Sep. 30, 2018	$ 6,929	2	15,571	(24,893)	15,699	550
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends and dividend equivalents declared per share or restricted stock unit (in usd per share)	$ 0
Beginning balance at Jun. 30, 2018		2	15,478	(23,892)	14,977	581
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued		0
Common stock repurchased/forfeited		0
Common stock and stock-based awards issued			3
Tax withholdings related to net share settlements of restricted stock units and awards			(36)
Stock-based compensation			125
Other			1
Common stock repurchased				(1,001)
Net income	$ 721				721
Dividends and dividend equivalents declared					0
Other					1
Foreign currency translation adjustment						(25)
Change in unrealized gains (losses) on investments	8					8
Change in unrealized gains (losses) on derivative instruments						(16)
Tax benefit (provision) on above items						2
Ending balance at Sep. 30, 2018	$ 6,929	2	15,571	(24,893)	15,699	550
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends and dividend equivalents declared per share or restricted stock unit (in usd per share)	$ 0
Beginning balance at Dec. 31, 2018	$ 6,281	2	15,716	(26,394)	16,459	498
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued		0
Common stock repurchased/forfeited		0
Common stock and stock-based awards issued			57
Tax withholdings related to net share settlements of restricted stock units and awards			(162)
Stock-based compensation			376
Other			1
Common stock repurchased	(4,000)			(4,002)
Net income	1,230				1,230
Dividends and dividend equivalents declared					(374)
Other					0
Foreign currency translation adjustment						(185)
Change in unrealized gains (losses) on investments	59					59
Change in unrealized gains (losses) on derivative instruments						5
Tax benefit (provision) on above items						(16)
Ending balance at Sep. 30, 2019	$ 3,270	2	15,988	(30,396)	17,315	361
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends and dividend equivalents declared per share or restricted stock unit (in usd per share)	$ 0.42
Beginning balance at Jun. 30, 2019		2	15,911	(29,396)	17,125	464
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued		0
Common stock repurchased/forfeited		0
Common stock and stock-based awards issued			2
Tax withholdings related to net share settlements of restricted stock units and awards			(43)
Stock-based compensation			116
Other			2
Common stock repurchased				(1,000)
Net income	$ 310				310
Dividends and dividend equivalents declared					(120)
Other					0
Foreign currency translation adjustment						(133)
Change in unrealized gains (losses) on investments	3					3
Change in unrealized gains (losses) on derivative instruments						35
Tax benefit (provision) on above items						(8)
Ending balance at Sep. 30, 2019	$ 3,270	$ 2	$ 15,988	$ (30,396)	$ 17,315	$ 361
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends and dividend equivalents declared per share or restricted stock unit (in usd per share)	$ 0.14