Summary of Long-Term Debt (Parenthetical) (Detail) In Billions, unless otherwise specified	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended		6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Mar. 28, 2015 Floating-rate notes due 2016	Sep. 27, 2014 Floating-rate notes due 2016	Mar. 28, 2015 Floating-rate notes due 2017	Sep. 27, 2014 Floating-rate notes due 2017	Mar. 28, 2015 Floating-rate notes due 2018	Sep. 27, 2014 Floating-rate notes due 2018	Mar. 28, 2015 Floating-rate notes due 2019	Sep. 27, 2014 Floating-rate notes due 2019	Mar. 28, 2015 Floating-rate notes due 2020	Sep. 27, 2014 Floating-rate notes due 2020	Mar. 28, 2015 2015 Debt Issuance USD ($)	Mar. 28, 2015 Fixed-rate 0.45% notes due 2016	Sep. 27, 2014 Fixed-rate 0.45% notes due 2016	Mar. 28, 2015 Fixed-rate 1.05% notes due 2017	Sep. 27, 2014 Fixed-rate 1.05% notes due 2017	Mar. 28, 2015 Fixed-rate 1.00% notes due 2018	Sep. 27, 2014 Fixed-rate 1.00% notes due 2018	Mar. 28, 2015 Fixed-rate 2.10% notes due 2019	Sep. 27, 2014 Fixed-rate 2.10% notes due 2019	Mar. 28, 2015 Fixed-rate 1.55% notes due 2020	Sep. 27, 2014 Fixed-rate 1.55% notes due 2020	Mar. 28, 2015 Fixed-rate 2.85% notes due 2021	Sep. 27, 2014 Fixed-rate 2.85% notes due 2021	Mar. 28, 2015 Fixed-rate 2.15% notes due 2022	Sep. 27, 2014 Fixed-rate 2.15% notes due 2022	Mar. 28, 2015 Fixed-rate 1.00% Euro-denominated notes due 2022	Sep. 27, 2014 Fixed-rate 1.00% Euro-denominated notes due 2022	Mar. 28, 2015 Fixed-rate 2.40% notes due 2023	Sep. 27, 2014 Fixed-rate 2.40% notes due 2023	Mar. 28, 2015 Fixed-rate 3.45% notes due 2024	Sep. 27, 2014 Fixed-rate 3.45% notes due 2024	Mar. 28, 2015 Fixed-rate 0.38% Swiss Franc-denominated notes due 2024	Sep. 27, 2014 Fixed-rate 0.38% Swiss Franc-denominated notes due 2024	Mar. 28, 2015 Fixed-rate 2.50% notes due 2025	Sep. 27, 2014 Fixed-rate 2.50% notes due 2025	Mar. 28, 2015 Fixed-rate 1.63% Euro-denominated notes due 2026	Sep. 27, 2014 Fixed-rate 1.63% Euro-denominated notes due 2026	Mar. 28, 2015 Fixed-rate 0.75% Swiss Franc-denominated notes due 2030	Sep. 27, 2014 Fixed-rate 0.75% Swiss Franc-denominated notes due 2030	Mar. 28, 2015 Fixed-rate 3.85% notes due 2043	Sep. 27, 2014 Fixed-rate 3.85% notes due 2043	Mar. 28, 2015 Fixed-rate 4.45% notes due 2044	Sep. 27, 2014 Fixed-rate 4.45% notes due 2044	Mar. 28, 2015 Fixed-rate 3.45% notes due 2045	Sep. 27, 2014 Fixed-rate 3.45% notes due 2045	Jun. 29, 2013 2013 Debt Issuance USD ($)	Jun. 28, 2014 2014 Debt Issuance USD ($)	Dec. 27, 2014 2015 Euro-Denominated Debt Issuance EUR (€)	Mar. 28, 2015 2015 Swiss Franc-Denominated Debt Issuance CHF
Debt Instrument [Line Items]
Debt instrument maturity year	2016	2016	2017	2017	2018	2018	2019	2019	2020	2020		2016	2016	2017	2017	2018	2018	2019	2019	2020	2020	2021	2021	2022	2022	2022	2022	2023	2023	2024	2024	2024	2024	2025	2025	2026	2026	2030	2030	2043	2043	2044	2044	2045	2045
Debt instrument interest rate												0.45%	0.45%	1.05%	1.05%	1.00%	1.00%	2.10%	2.10%	1.55%	1.55%	2.85%	2.85%	2.15%	2.15%	1.00%	1.00%	2.40%	2.40%	3.45%	3.45%	0.38%	0.38%	2.50%	2.50%	1.63%	1.63%	0.75%	0.75%	3.85%	3.85%	4.45%	4.45%	3.45%	3.45%
Debt instrument, face amount											$ 6.5																																			$ 17.0	$ 12.0	€ 2.8	1.3