Summary of Long-Term Debt (Detail) (USD $) In Millions, unless otherwise specified	Mar. 28, 2015		Sep. 27, 2014
Debt Instrument [Line Items]
Total borrowings	$ 39,875		$ 29,000
Unamortized discount	(80)		(52)
Hedge accounting fair value adjustments	277		39
Total long-term debt	40,072		28,987
Floating-rate notes due 2016
Debt Instrument [Line Items]
Debt instrument, senior notes	1,000	[1]	1,000	[1]
Debt instrument effective interest rate	0.51%	[1]	0.51%	[1]
Floating-rate notes due 2017
Debt Instrument [Line Items]
Debt instrument, senior notes	1,000	[2]	1,000	[2]
Debt instrument effective interest rate	0.33%	[2]	0.31%	[2]
Floating-rate notes due 2018
Debt Instrument [Line Items]
Debt instrument, senior notes	2,000	[1]	2,000	[1]
Debt instrument effective interest rate	1.10%	[1]	1.10%	[1]
Floating-rate notes due 2019
Debt Instrument [Line Items]
Debt instrument, senior notes	1,000	[2]	1,000	[2]
Debt instrument effective interest rate	0.56%	[2]	0.54%	[2]
Floating-rate notes due 2020
Debt Instrument [Line Items]
Debt instrument, senior notes	500	[3]	0	[3]
Debt instrument effective interest rate	0.51%	[3]	0.00%	[3]
Fixed-rate 0.45% notes due 2016
Debt Instrument [Line Items]
Debt instrument, senior notes	1,500	[1]	1,500	[1]
Debt instrument effective interest rate	0.51%	[1]	0.51%	[1]
Fixed-rate 1.05% notes due 2017
Debt Instrument [Line Items]
Debt instrument, senior notes	1,500	[2]	1,500	[2]
Debt instrument effective interest rate	0.32%	[2]	0.30%	[2]
Fixed-rate 1.00% notes due 2018
Debt Instrument [Line Items]
Debt instrument, senior notes	4,000	[1]	4,000	[1]
Debt instrument effective interest rate	1.08%	[1]	1.08%	[1]
Fixed-rate 2.10% notes due 2019
Debt Instrument [Line Items]
Debt instrument, senior notes	2,000	[2]	2,000	[2]
Debt instrument effective interest rate	0.55%	[2]	0.53%	[2]
Fixed-rate 1.55% notes due 2020
Debt Instrument [Line Items]
Debt instrument, senior notes	1,250	[3]	0	[3]
Debt instrument effective interest rate	0.50%	[3]	0.00%	[3]
Fixed-rate 2.85% notes due 2021
Debt Instrument [Line Items]
Debt instrument, senior notes	3,000	[2]	3,000	[2]
Debt instrument effective interest rate	0.81%	[2]	0.79%	[2]
Fixed-rate 2.15% notes due 2022
Debt Instrument [Line Items]
Debt instrument, senior notes	1,250	[3]	0	[3]
Debt instrument effective interest rate	0.82%	[3]	0.00%	[3]
Fixed-rate 1.00% Euro-denominated notes due 2022
Debt Instrument [Line Items]
Debt instrument, senior notes	1,534	[4]	0	[4]
Debt instrument effective interest rate	2.94%	[4]	0.00%	[4]
Fixed-rate 2.40% notes due 2023
Debt Instrument [Line Items]
Debt instrument, senior notes	5,500	[1]	5,500	[1]
Debt instrument effective interest rate	2.44%	[1]	2.44%	[1]
Fixed-rate 3.45% notes due 2024
Debt Instrument [Line Items]
Debt instrument, senior notes	2,500	[2]	2,500	[2]
Debt instrument effective interest rate	0.92%	[2]	0.90%	[2]
Fixed-rate 0.38% Swiss Franc-denominated notes due 2024
Debt Instrument [Line Items]
Debt instrument, senior notes	915	[5]	0	[5]
Debt instrument effective interest rate	0.28%	[5]	0.00%	[5]
Fixed-rate 2.50% notes due 2025
Debt Instrument [Line Items]
Debt instrument, senior notes	1,500	[3]	0	[3]
Debt instrument effective interest rate	2.60%	[3]	0.00%	[3]
Fixed-rate 1.63% Euro-denominated notes due 2026
Debt Instrument [Line Items]
Debt instrument, senior notes	1,534	[4]	0	[4]
Debt instrument effective interest rate	3.45%	[4]	0.00%	[4]
Fixed-rate 0.75% Swiss Franc-denominated notes due 2030
Debt Instrument [Line Items]
Debt instrument, senior notes	392	[5]	0	[5]
Debt instrument effective interest rate	0.74%	[5]	0.00%	[5]
Fixed-rate 3.85% notes due 2043
Debt Instrument [Line Items]
Debt instrument, senior notes	3,000	[1]	3,000	[1]
Debt instrument effective interest rate	3.91%	[1]	3.91%	[1]
Fixed-rate 4.45% notes due 2044
Debt Instrument [Line Items]
Debt instrument, senior notes	1,000	[2]	1,000	[2]
Debt instrument effective interest rate	4.48%	[2]	4.48%	[2]
Fixed-rate 3.45% notes due 2045
Debt Instrument [Line Items]
Debt instrument, senior notes	$ 2,000	[3]	$ 0	[3]
Debt instrument effective interest rate	3.58%	[3]	0.00%	[3]

[1] Tranche relates to the $17.0 billion debt issuance in the third quarter of 2013.

[2] Tranche relates to the $12.0 billion debt issuance in the third quarter of 2014.

[3] Tranche relates to the $6.5 billion debt issuance in the second quarter of 2015.

[4] Tranche relates to Euro-denominated debt issuance of €2.8 billion in the first quarter of 2015.

[5] Tranche relates to Swiss Franc-denominated debt issuance of SFr1.3 billion in the second quarter of 2015.