Equity (Impact of Reclassifications from Accumulated Other Comprehensive Income on Earnings) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2023	Jan. 01, 2023
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Interest income and other, net	$ 33.8	$ 11.6
Amounts Reclassified from AOCI, Interest expense	140.1	129.7
Amounts Reclassified from AOCI, Tax (expense)/benefit	354.7	279.8
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Total before tax	(24.9)	98.4
Amounts Reclassified from AOCI, Tax (expense)/benefit	1.8	(11.8)
Amounts Reclassified from AOCI, Net of tax	(23.1)	86.6
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Net of tax	(0.2)	(0.1)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Interest income and other, net	(0.3)	(0.2)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Net of tax	(29.6)	82.7
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Total before tax	(33.5)	93.3
Accumulated Net Investment Hedge Gain (Loss) Attributable to Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Net of tax	6.7	4.0
Accumulated Net Investment Hedge Gain (Loss) Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from AOCI, Interest expense	$ 8.9	$ 5.3