Condensed Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent	Retained Earnings [Member]	Noncontrolling Interest [Member]
Beginning period (in shares) at Dec. 31, 2017		1,308
Beginning Balance at Dec. 31, 2017	$ 20,501	$ 1	$ 1,264	$ 165	$ 19,012	$ 59
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,358				3,355	3
Other comprehensive income, net of tax	130			130
Issuances under employee stock purchase plan, Shares		1
Issuances under employee stock purchase plan	48		48
Issuance under equity incentive plans, Shares		8
Issuances under equity incentive plans	109		109
Stock-based compensation	477		477
Repurchases of common stock, shares		(21)
Repurchases of common stock	(1,580)		(54)		(1,526)
Dividends declared	(1,499)				(1,499)
Ending period (in shares) at Jun. 30, 2018		1,296
Ending Balance at Jun. 30, 2018	21,734	$ 1	1,844	2	19,825	62
Beginning period (in shares) at Mar. 31, 2018		1,300
Beginning Balance at Mar. 31, 2018	20,651	$ 1	1,564	(170)	19,196	60
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,819				1,817	2
Other comprehensive income, net of tax	172			172
Issuance under equity incentive plans, Shares		3
Issuances under equity incentive plans	45		45
Stock-based compensation	253		253
Repurchases of common stock, shares		(7)
Repurchases of common stock	(459)		(18)		(441)
Dividends declared	(747)				(747)
Ending period (in shares) at Jun. 30, 2018		1,296
Ending Balance at Jun. 30, 2018	$ 21,734	$ 1	1,844	2	19,825	62
Beginning period (in shares) at Dec. 31, 2018	1,282	1,282
Beginning Balance at Dec. 31, 2018	$ 21,534	$ 1	2,282	80	19,024	147
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,843				3,855	(12)
Other comprehensive income, net of tax	22			22
Issuances under employee stock purchase plan, Shares		1
Issuances under employee stock purchase plan	63		63
Issuance under equity incentive plans, Shares		6
Issuances under equity incentive plans	82		82
Stock-based compensation	319		319
Repurchases of common stock, shares		(22)
Repurchases of common stock	(1,496)		(62)		(1,434)
Dividends declared	$ (1,624)				(1,624)
Ending period (in shares) at Jun. 30, 2019	1,267	1,267
Ending Balance at Jun. 30, 2019	$ 22,751	$ 1	2,684	102	19,829	135
Beginning period (in shares) at Mar. 31, 2019		1,274
Beginning Balance at Mar. 31, 2019	22,091	$ 1	2,494	130	19,326	140
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,875				1,880	(5)
Other comprehensive income, net of tax	(28)			(28)
Issuance under equity incentive plans, Shares		2
Issuances under equity incentive plans	41		41
Stock-based compensation	175		175
Repurchases of common stock, shares		(9)
Repurchases of common stock	(593)		(26)		(567)
Dividends declared	$ (810)				(810)
Ending period (in shares) at Jun. 30, 2019	1,267	1,267
Ending Balance at Jun. 30, 2019	$ 22,751	$ 1	$ 2,684	$ 102	$ 19,829	$ 135