Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Dec. 27, 2020	Dec. 29, 2019
Net earnings including noncontrolling interests	$ 622.2	$ 885.3
Other comprehensive loss, net of tax:
Other comprehensive income/(loss)	218.7	111.1
Comprehensive income/(loss) including noncontrolling interests	840.9	996.4
Comprehensive income/(loss) attributable to noncontrolling interests	0.0	(0.4)
Comprehensive income/(loss) attributable to Starbucks	840.9	996.8
Available-for-sale Securities [Member]
Other comprehensive loss, net of tax:
Unrealized holding gains/(losses) on available-for-sale securities, before tax	(0.5)	(0.1)
Unrealized holding gains/(losses) on available-for-sale securities, tax (expense)/benefit	0.1	0.0
Cash Flow Hedging [Member]
Other comprehensive loss, net of tax:
Unrealized gains/(losses) on hedging instruments, before tax	7.7	32.4
Unrealized gains/(losses) on hedging instruments, tax (expense)/benefit	(2.9)	(6.6)
Net Investment Hedging [Member]
Other comprehensive loss, net of tax:
Unrealized gains/(losses) on hedging instruments, before tax	(30.2)	23.7
Unrealized gains/(losses) on hedging instruments, tax (expense)/benefit	7.6	(6.0)
Translation Adjustment [Member]
Other comprehensive loss, net of tax:
Translation adjustment and other, before tax	238.7	76.1
Translation adjustment and other, tax (expense)/benefit	0.0	0.0
Other comprehensive income/(loss)	238.7	76.1
Reclassification out of Accumulated Other Comprehensive Income [Member]
Other comprehensive loss, net of tax:
Reclassification adjustment for net (gains)/losses realized in net earnings for available-for-sale securities, hedging instruments, and translation adjustment, before tax	(3.6)	(10.7)
Reclassification adjustment for net (gains)/losses realized in net earnings for available-for-sale securities, hedging instruments, and translation adjustment, tax expense/(benefit)	$ 1.8	$ 2.3