Earnings Per Share (Schedule of computation of basic and diluted net income (loss) per share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Jul. 03, 2015	Jun. 27, 2014	Jun. 28, 2013
Numerator:
Net income attributable to Seagate Technology plc	$ 1,742	$ 1,570	$ 1,838
Number of shares used in per share calculations:
Total shares for purposes of calculating basic net income per share attributable to Seagate Technology plc	324	337	370
Weighted-average effect of dilutive securities:
Employee equity award plans	7	10	12
Total shares for purpose of calculating diluted net income per share attributable to Seagate Technology plc	331	347	382
Net income per share attributable to Seagate Technology plc ordinary shareholders:
Basic net income per share (in dollars per share)	$ 5.38	$ 4.66	$ 4.97
Diluted net income per share (in dollars per share)	$ 5.26	$ 4.52	$ 4.81