Retirement Plans - Pre-Tax in AOCI for Defined Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 27, 2019	Sep. 28, 2018
Non-U.S. Plans
Defined Benefit Plan Disclosure
Current year net actuarial (gain) loss recorded in accumulated other comprehensive income (loss)	$ (204)	$ 13
Amortization of net actuarial loss	24	24
Current year prior service cost (credit) recorded in accumulated other comprehensive income (loss)	(8)	5
Amortization of prior service cost (credit)	(7)	(6)
Total	(195)	36
Estimated amortization of actuarial losses from accumulated other comprehensive income into net periodic pension benefit cost in next fiscal year
Amortization of net actuarial loss	40
Amortization of prior service credit	6
U.S. Plans
Defined Benefit Plan Disclosure
Current year net actuarial (gain) loss recorded in accumulated other comprehensive income (loss)	(83)	46
Amortization of net actuarial loss	17	22
Total	(66)	$ 68
Estimated amortization of actuarial losses from accumulated other comprehensive income into net periodic pension benefit cost in next fiscal year
Amortization of net actuarial loss	$ 9