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 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]
Repurchase of common stock (in shares)	(51)
Ending Balance (in shares) at Oct. 28, 2017		4,951
Ending Balance at Oct. 28, 2017	$ 65,550		44,872	20,647	31	65,550	0
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)	(6,384)			(6,384)		(6,384)
Other comprehensive income (loss)	37				37	37
Issuance of common stock (in shares)		52
Issuance of common stock	302		302			302
Repurchase of common stock (in shares)		(154)
Repurchase of common stock	(5,631)		(1,393)	(4,238)		(5,631)
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	(433)		(433)			(433)
Cash dividends declared	(2,861)			(2,861)		(2,861)
Share-based compensation	785		785			785
Purchase acquisitions and other	21		21			21
Ending Balance (in shares) at Jan. 27, 2018		4,868
Ending Balance at Jan. 27, 2018	51,982		44,535	7,364	83	51,982	0
Beginning balance (in shares) at Oct. 28, 2017		4,951
Beginning balance at Oct. 28, 2017	65,550		44,872	20,647	31	65,550	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(8,778)			(8,778)		(8,778)
Other comprehensive income (loss)	52				52	52	0
Issuance of common stock (in shares)		22
Issuance of common stock	$ 293		293			293
Repurchase of common stock (in shares)	(103)	(103)
Repurchase of common stock	$ (4,011)		(931)	(3,080)		(4,011)
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	(91)		(91)			(91)
Cash dividends declared	(1,425)			(1,425)		(1,425)
Share-based compensation	393		393			393
Purchase acquisitions and other	(1)		(1)			(1)
Ending Balance (in shares) at Jan. 27, 2018		4,868
Ending Balance at Jan. 27, 2018	51,982		44,535	7,364	83	51,982	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Effect of adoption of accounting standards	9			9		9
Beginning balance (in shares) at Jul. 28, 2018		4,614
Beginning balance at Jul. 28, 2018	$ 43,204		42,820	1,233	(849)	43,204	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of common stock (in shares)	(109)
Ending Balance (in shares) at Oct. 27, 2018		4,517
Ending Balance at Oct. 27, 2018	$ 43,848		41,897	3,169	(1,218)	43,848	0
Beginning balance (in shares) at Jul. 28, 2018		4,614
Beginning 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)	6,371			6,371		6,371
Other comprehensive income (loss)	(93)				(93)	(93)
Issuance of common stock (in shares)		41
Issuance of common stock	312		312			312
Repurchase of common stock (in shares)		(220)
Repurchase of common stock	(10,042)		(2,049)	(7,993)		(10,042)
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)		(11)
Shares repurchased for tax withholdings on vesting of restricted stock units	(514)		(514)			(514)
Cash dividends declared	(2,970)			(2,970)		(2,970)
Share-based compensation	792		792			792
Ending Balance (in shares) at Jan. 26, 2019		4,424
Ending Balance at Jan. 26, 2019	40,789		41,361	538	(1,110)	40,789	0
Beginning balance (in shares) at Oct. 27, 2018		4,517
Beginning balance at Oct. 27, 2018	43,848		41,897	3,169	(1,218)	43,848	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,822			2,822		2,822
Other comprehensive income (loss)	108				108	108
Issuance of common stock (in shares)		22
Issuance of common stock	$ 304		304			304
Repurchase of common stock (in shares)	(111)	(111)
Repurchase of common stock	$ (5,016)		(1,033)	(3,983)		(5,016)
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)		(4)
Shares repurchased for tax withholdings on vesting of restricted stock units	(196)		(196)			(196)
Cash dividends declared	(1,470)			(1,470)		(1,470)
Share-based compensation	389		389			389
Ending Balance (in shares) at Jan. 26, 2019		4,424
Ending Balance at Jan. 26, 2019	40,789		$ 41,361	538	(1,110)	40,789	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Effect of adoption of accounting standards	$ 3,729			$ 3,897	$ (168)	$ 3,729