CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Apr. 01, 2017	Mar. 31, 2018	Apr. 01, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 13,822	$ 11,029	$ 33,887	$ 28,920
Other comprehensive income/(loss):
Change in foreign currency translation, net of tax effects of $8, $(44), $7 and $32, respectively	263	214	303	(161)
Change in unrealized gains/losses on derivative instruments:
Change in fair value of derivatives, net of tax benefit/(expense) of $(64), $(25), $(130) and $(253), respectively	(27)	(300)	61	1,168
Adjustment for net (gains)/losses realized and included in net income, net of tax expense/(benefit) of $77, $311, $56 and $100, respectively	(207)	(1,032)	(105)	(726)
Total change in unrealized gains/losses on derivative instruments, net of tax	(234)	(1,332)	(44)	442
Change in unrealized gains/losses on marketable securities:
Change in fair value of marketable securities, net of tax benefit/(expense) of $541, $(256), $1,005 and $733, respectively	(2,003)	464	(2,849)	(1,344)
Adjustment for net (gains)/losses realized and included in net income, net of tax expense/(benefit) of $(7), $7, $34 and $(4), respectively	29	(13)	(46)	7
Total change in unrealized gains/losses on marketable securities, net of tax	(1,974)	451	(2,895)	(1,337)
Total other comprehensive income/(loss)	(1,945)	(667)	(2,636)	(1,056)
Total comprehensive income	$ 11,877	$ 10,362	$ 31,251	$ 27,864