Consolidated Statements of Equity - USD ($) shares in Millions, $ in Millions	Total	Shares of Common Stock	Common Stock and Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Total Cisco Shareholders’ Equity	Non-controlling Interests
Beginning balance (in shares) at Jul. 29, 2017		4,983
Beginning balance at Jul. 29, 2017	$ 66,137		$ 45,253	$ 20,838	$ 46	$ 66,137	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(3,693)			(3,693)		(3,693)
Other comprehensive income (loss)	(695)				(695)	(695)
Issuance of common stock (in shares)		61
Issuance of common stock	318		318			318
Repurchase of common stock (in shares)		(294)
Repurchase of common stock	(11,646)		(2,679)	(8,967)		(11,646)
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)		(16)
Shares repurchased for tax withholdings on vesting of restricted stock units	(541)		(541)			(541)
Cash dividends declared	(4,433)			(4,433)		(4,433)
Effect of adoption of accounting standards	9			(36)	45	9
Share-based compensation	1,184		1,184			1,184
Purchase acquisitions and other	21		21			21
Ending Balance (in shares) at Apr. 28, 2018		4,734
Ending Balance at Apr. 28, 2018	46,661		43,556	3,709	(604)	46,661	0
Beginning balance (in shares) at Jan. 27, 2018		4,868
Beginning balance at Jan. 27, 2018	51,982		44,535	7,364	83	51,982	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,691			2,691		2,691
Other comprehensive income (loss)	(732)				(732)	(732)	0
Issuance of common stock (in shares)		9
Issuance of common stock	$ 16		16			16
Repurchase of common stock (in shares)	(140)	(140)
Repurchase of common stock	$ (6,015)		(1,286)	(4,729)		(6,015)
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)		(3)
Shares repurchased for tax withholdings on vesting of restricted stock units	(108)		(108)			(108)
Cash dividends declared	(1,572)			(1,572)		(1,572)
Effect of adoption of accounting standards	0			(45)	45
Share-based compensation	399		399			399
Purchase acquisitions and other	0					0
Ending Balance (in shares) at Apr. 28, 2018		4,734
Ending Balance at Apr. 28, 2018	$ 46,661		43,556	3,709	(604)	46,661	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of common stock (in shares)	(138)
Ending Balance (in shares) at Jul. 28, 2018		4,614
Ending Balance at Jul. 28, 2018	$ 43,204		42,820	1,233	(849)	43,204	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	9,415			9,415		9,415
Other comprehensive income (loss)	121				121	121
Issuance of common stock (in shares)		48
Issuance of common stock	321		321			321
Repurchase of common stock (in shares)		(336)
Repurchase of common stock	(16,062)		(3,129)	(12,933)		(16,062)
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)		(13)
Shares repurchased for tax withholdings on vesting of restricted stock units	(601)		(601)			(601)
Cash dividends declared	(4,489)			(4,489)		(4,489)
Effect of adoption of accounting standards	3,729			3,897	(168)	3,729
Share-based compensation	1,166		1,166			1,166
Ending Balance (in shares) at Apr. 27, 2019		4,313
Ending Balance at Apr. 27, 2019	36,804		40,577	(2,877)	(896)	36,804	0
Beginning balance (in shares) at Jan. 26, 2019		4,424
Beginning balance at Jan. 26, 2019	40,789		41,361	538	(1,110)	40,789	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	3,044			3,044		3,044
Other comprehensive income (loss)	214				214	214
Issuance of common stock (in shares)		7
Issuance of common stock	$ 9		9			9
Repurchase of common stock (in shares)	(116)	(116)
Repurchase of common stock	$ (6,020)		(1,080)	(4,940)		(6,020)
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)		(2)
Shares repurchased for tax withholdings on vesting of restricted stock units	(87)		(87)			(87)
Cash dividends declared	(1,519)			(1,519)		(1,519)
Share-based compensation	374		374			374
Ending Balance (in shares) at Apr. 27, 2019		4,313
Ending Balance at Apr. 27, 2019	$ 36,804		$ 40,577	$ (2,877)	$ (896)	$ 36,804	$ 0