Accumulated Other Comprehensive (Loss) Income and Supplemental Equity Disclosure - Supplemental Equity Schedule (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Oct. 27, 2017	Oct. 28, 2016	Oct. 27, 2017	Oct. 28, 2016	Apr. 28, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance			$ 50,416	$ 52,063
Net income (loss)	$ 2,013	$ 1,111	3,022	2,040
Other comprehensive income (loss)	(136)	(304)	553	(460)
Dividends to shareholders			(1,247)	(1,192)
Issuance of shares under stock purchase and award plans			177	260
Repurchase of ordinary shares			(1,835)	(2,794)
Tax benefit from exercise of stock-based awards				75
Stock-based compensation			198	190
Cumulative effect of change in accounting principle					$ 296
Reductions of noncontrolling ownership interests			(2)
Additions of noncontrolling ownership interests				111
Balance	51,578	50,293	51,578	50,293
Total Shareholders' Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance			50,294	52,063
Net income (loss)			3,033	2,044
Other comprehensive income (loss)			553	(460)
Dividends to shareholders			(1,247)	(1,192)
Issuance of shares under stock purchase and award plans			177	260
Repurchase of ordinary shares			(1,835)	(2,794)
Tax benefit from exercise of stock-based awards				75
Stock-based compensation			198	190
Cumulative effect of change in accounting principle					$ 296
Balance	51,469	50,186	51,469	50,186
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance			122	0
Net income (loss)			(11)	(4)
Other comprehensive income (loss)			0	0
Reductions of noncontrolling ownership interests			(2)
Additions of noncontrolling ownership interests				111
Balance	$ 109	$ 107	$ 109	$ 107