CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Millions, $ in Millions	Total	Common Stock Shares	Treasury Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Beginning balance (in shares) at Dec. 31, 2017		1,200
Beginning balance at Dec. 31, 2017	$ 15,994		$ (2,001)	$ 14,314	$ (142)	$ 3,823
Increase (Decrease) in Stockholders' Equity
Net income	511					511
Foreign currency translation	2				2
Unrealized gains (losses) on investments, net	(15)				(15)
Tax benefit (expense) on unrealized (losses) gains on investments, net	4				4
Unrealized gains (losses) on hedging activities, net	(18)				(18)
Common stock and stock-based awards issued and assumed, net of shares withheld for employee taxes (in shares)		7
Common stock and stock-based awards issued and assumed, net of shares withheld for employee taxes	(226)			(226)
Common stock repurchased (in shares)		(24)
Common stock repurchased	(1,825)		(1,810)	(15)
Stock-based compensation	214			214
Ending balance (in shares) at Mar. 31, 2018		1,183
Ending balance at Mar. 31, 2018	14,641		(3,811)	14,287	(169)	4,334
Beginning balance (in shares) at Dec. 31, 2017		1,200
Beginning balance at Dec. 31, 2017	15,994		(2,001)	14,314	(142)	3,823
Increase (Decrease) in Stockholders' Equity
Net income	1,473
Foreign currency translation	(33)
Unrealized gains (losses) on investments, net	(6)
Tax benefit (expense) on unrealized (losses) gains on investments, net	2
Ending balance (in shares) at Sep. 30, 2018		1,178
Ending balance at Sep. 30, 2018	15,115		(4,911)	14,664	66	5,296
Beginning balance (in shares) at Mar. 31, 2018		1,183
Beginning balance at Mar. 31, 2018	14,641		(3,811)	14,287	(169)	4,334
Increase (Decrease) in Stockholders' Equity
Net income	526					526
Foreign currency translation	(29)				(29)
Unrealized gains (losses) on investments, net	5				5
Tax benefit (expense) on unrealized (losses) gains on investments, net	(1)				(1)
Unrealized gains (losses) on hedging activities, net	233				233
Tax (expense) benefit on unrealized losses on hedging activities, net	(3)				(3)
Common stock and stock-based awards issued and assumed, net of shares withheld for employee taxes (in shares)		7
Common stock and stock-based awards issued and assumed, net of shares withheld for employee taxes	(67)			(67)
Common stock repurchased (in shares)		(6)
Common stock repurchased	(500)		(500)
Stock-based compensation	214			214
Ending balance (in shares) at Jun. 30, 2018		1,184
Ending balance at Jun. 30, 2018	15,019		(4,311)	14,434	36	4,860
Increase (Decrease) in Stockholders' Equity
Net income	436					436
Foreign currency translation	(6)				(6)
Unrealized gains (losses) on investments, net	4				4
Tax benefit (expense) on unrealized (losses) gains on investments, net	(1)				(1)
Unrealized gains (losses) on hedging activities, net	34				34
Tax (expense) benefit on unrealized losses on hedging activities, net	(1)				(1)
Common stock and stock-based awards issued and assumed, net of shares withheld for employee taxes (in shares)		1
Common stock and stock-based awards issued and assumed, net of shares withheld for employee taxes	9			9
Common stock repurchased (in shares)		(7)
Common stock repurchased	(600)		(600)
Stock-based compensation	221			221
Ending balance (in shares) at Sep. 30, 2018		1,178
Ending balance at Sep. 30, 2018	$ 15,115		(4,911)	14,664	66	5,296
Beginning balance (in shares) at Dec. 31, 2018	1,174	1,174
Beginning balance at Dec. 31, 2018	$ 15,386		(5,511)	14,939	78	5,880
Increase (Decrease) in Stockholders' Equity
Net income	667					667
Foreign currency translation	(67)				(67)
Unrealized gains (losses) on investments, net	11				11
Tax benefit (expense) on unrealized (losses) gains on investments, net	(2)				(2)
Unrealized gains (losses) on hedging activities, net	(46)				(46)
Tax (expense) benefit on unrealized losses on hedging activities, net	1				1
Common stock and stock-based awards issued and assumed, net of shares withheld for employee taxes (in shares)		6
Common stock and stock-based awards issued and assumed, net of shares withheld for employee taxes	(302)			(302)
Common stock repurchased (in shares)		(8)
Common stock repurchased	(750)		(705)	(45)
Stock-based compensation	256			256
Ending balance (in shares) at Mar. 31, 2019		1,172
Ending balance at Mar. 31, 2019	$ 15,157		(6,216)	14,848	(25)	6,550
Beginning balance (in shares) at Dec. 31, 2018	1,174	1,174
Beginning balance at Dec. 31, 2018	$ 15,386		(5,511)	14,939	78	5,880
Increase (Decrease) in Stockholders' Equity
Net income	1,952
Foreign currency translation	(148)
Unrealized gains (losses) on investments, net	16
Tax benefit (expense) on unrealized (losses) gains on investments, net	$ (5)
Ending balance (in shares) at Sep. 30, 2019	1,174	1,174
Ending balance at Sep. 30, 2019	$ 16,483		(6,566)	15,266	(52)	7,835
Beginning balance (in shares) at Mar. 31, 2019		1,172
Beginning balance at Mar. 31, 2019	15,157		(6,216)	14,848	(25)	6,550
Increase (Decrease) in Stockholders' Equity
Net income	823					823
Foreign currency translation	9				9
Unrealized gains (losses) on investments, net	10				10
Tax benefit (expense) on unrealized (losses) gains on investments, net	(4)				(4)
Unrealized gains (losses) on hedging activities, net	(18)				(18)
Common stock and stock-based awards issued and assumed, net of shares withheld for employee taxes (in shares)		5
Common stock and stock-based awards issued and assumed, net of shares withheld for employee taxes	(73)			(73)
Stock-based compensation	235			235
Ending balance (in shares) at Jun. 30, 2019		1,177
Ending balance at Jun. 30, 2019	16,139		(6,216)	15,010	(28)	7,373
Increase (Decrease) in Stockholders' Equity
Net income	462					462
Foreign currency translation	(90)				(90)
Unrealized gains (losses) on investments, net	(5)				(5)
Tax benefit (expense) on unrealized (losses) gains on investments, net	1				1
Unrealized gains (losses) on hedging activities, net	71				71
Tax (expense) benefit on unrealized losses on hedging activities, net	(1)				(1)
Common stock and stock-based awards issued and assumed, net of shares withheld for employee taxes	(19)			(19)
Common stock repurchased (in shares)		(3)
Common stock repurchased	(350)		(350)
Stock-based compensation	$ 275			275
Ending balance (in shares) at Sep. 30, 2019	1,174	1,174
Ending balance at Sep. 30, 2019	$ 16,483		$ (6,566)	$ 15,266	$ (52)	$ 7,835