Employee Benefit Plans Employee Savings and Retirement Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 25, 2016	Sep. 27, 2015	Sep. 28, 2014
Employee Savings and Retirement Plan [Abstract]
Percentage of eligible employee compensation that can be contributed to 401(k) plan subject to annual limits	85.00%
Company's contribution expense to 401(k) plan	$ 74	$ 81	$ 77