Summary of Dividends Declared and Paid (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended						6 Months Ended		12 Months Ended
	Mar. 26, 2016	Dec. 26, 2015	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Dec. 27, 2014	Mar. 26, 2016	Mar. 28, 2015	Sep. 26, 2015
Dividends [Line Items]
Dividend Per Share	$ 0.52	$ 0.52	$ 0.52	$ 0.52	$ 0.47	$ 0.47	$ 1.04	$ 0.94	$ 1.98
Amount	$ 2,879	$ 2,898	$ 2,950	$ 2,997	$ 2,734	$ 2,750	$ 5,777		$ 11,431