Summary of Long-Term Debt (Parenthetical) (Detail) In Millions, unless otherwise specified			3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended
	Dec. 27, 2014 USD ($)	Sep. 27, 2014 USD ($)	Dec. 27, 2014 Floating-rate notes due 2016	Sep. 27, 2014 Floating-rate notes due 2016	Dec. 27, 2014 Floating-rate notes due 2017	Sep. 27, 2014 Floating-rate notes due 2017	Dec. 27, 2014 Floating-rate notes due 2018	Sep. 27, 2014 Floating-rate notes due 2018	Dec. 27, 2014 Floating-rate notes due 2019	Sep. 27, 2014 Floating-rate notes due 2019	Dec. 27, 2014 Fixed-rate 0.45% notes due 2016	Sep. 27, 2014 Fixed-rate 0.45% notes due 2016	Dec. 27, 2014 Fixed-rate 1.05% notes due 2017	Sep. 27, 2014 Fixed-rate 1.05% notes due 2017	Dec. 27, 2014 Fixed-rate 1.00% notes due 2018	Sep. 27, 2014 Fixed-rate 1.00% notes due 2018	Dec. 27, 2014 Fixed-rate 2.10% notes due 2019	Sep. 27, 2014 Fixed-rate 2.10% notes due 2019	Dec. 27, 2014 Fixed-rate 2.85% notes due 2021	Sep. 27, 2014 Fixed-rate 2.85% notes due 2021	Dec. 27, 2014 Fixed-rate 1.00% Euro-denominated notes due 2022	Sep. 27, 2014 Fixed-rate 1.00% Euro-denominated notes due 2022	Dec. 27, 2014 Fixed-rate 2.40% notes due 2023	Sep. 27, 2014 Fixed-rate 2.40% notes due 2023	Dec. 27, 2014 Fixed-rate 3.45% notes due 2024	Sep. 27, 2014 Fixed-rate 3.45% notes due 2024	Dec. 27, 2014 Fixed-rate 1.63% Euro-denominated notes due 2026	Sep. 27, 2014 Fixed-rate 1.63% Euro-denominated notes due 2026	Dec. 27, 2014 Fixed-rate 3.85% notes due 2043	Sep. 27, 2014 Fixed-rate 3.85% notes due 2043	Dec. 27, 2014 Fixed-rate 4.45% notes due 2044	Sep. 27, 2014 Fixed-rate 4.45% notes due 2044	Jun. 29, 2013 2013 Debt Issuance USD ($)	Jun. 28, 2014 2014 Debt Issuance USD ($)	Dec. 27, 2014 2015 Euro-Denominated Debt Issuance EUR (€)
Debt Instrument [Line Items]
Debt instrument maturity year			2016	2016	2017	2017	2018	2018	2019	2019	2016	2016	2017	2017	2018	2018	2019	2019	2021	2021	2022	2022	2023	2023	2024	2024	2026	2026	2043	2043	2044	2044
Debt instrument interest rate											0.45%	0.45%	1.05%	1.05%	1.00%	1.00%	2.10%	2.10%	2.85%	2.85%	1.00%	1.00%	2.40%	2.40%	3.45%	3.45%	1.63%	1.63%	3.85%	3.85%	4.45%	4.45%
Debt instrument aggregate principal amount	$ 32,418	$ 29,000																															$ 17,000	$ 12,000	€ 2,800