CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net income	$ 1,305	$ 1,070
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	123	105
Deferred income taxes, net	(22)	23
Premium and discount amortization on available-for-sale securities and bank loans and net unrealized gain/loss on other investments	(37)	40
Provisions for credit losses and legal and regulatory proceedings	191	72
Share-based compensation expense	192	149
Unrealized (gain)/loss on company-owned life insurance policies, net of expenses	(125)	136
Other	(1)	25
Net change in:
Assets segregated for regulatory purposes excluding cash and cash equivalents	0	101
Collateralized agreements, net of collateralized financings	9	10
Loans (provided to) financial advisors, net of repayments	16	(85)
Brokerage client receivables and other receivables, net	456	(57)
Trading instruments, net	62	126
Derivative instruments, net	(224)	246
Other assets	(43)	(97)
Brokerage client payables and other payables	(5,764)	2,985
Accrued compensation, commissions and benefits	(95)	(261)
Purchases and originations of loans held for sale, net of proceeds from sales of securitizations and loans held for sale	9	(18)
Net cash provided by/(used in) operating activities	(3,948)	4,570
Cash flows from investing activities:
Increase in bank loans, net	(762)	(5,377)
Proceeds from sales of loans held for investment	600	191
Purchases of available-for-sale securities	(561)	(2,743)
Available-for-sale securities maturations, repayments and redemptions	977	1,346
Proceeds from sales of available-for-sale securities	0	2
Cash and cash equivalents acquired in business acquisitions, including those segregated for regulatory purposes, net of cash paid for acquisitions	0	1,769
Additions to property and equipment	(122)	(68)
Sales of Federal Home Loan Bank stock, net	3	0
Investment in note receivable	0	(125)
Purchases of other investments, net	(6)	(33)
Other investing activities, net	(61)	(81)
Net cash provided by/(used in) investing activities	68	(5,119)
Cash flows from financing activities:
Increase in bank deposits	2,411	4,800
Repurchases of common stock and share-based awards withheld for payment of withholding tax requirements	(860)	(160)
Dividends on preferred and common stock	(266)	(200)
Exercise of stock options and employee stock purchases	37	44
Redemption of preferred stock	(40)	0
Proceeds from Federal Home Loan Bank advances	2,550	1,025
Repayments of Federal Home Loan Bank advances and other borrowed funds	(2,741)	(906)
Other financing, net	(2)	(5)
Net cash provided by financing activities	1,089	4,598
Currency adjustment:
Effect of exchange rate changes on cash and cash equivalents, including those segregated for regulatory purposes	346	(289)
Net increase/(decrease) in cash and cash equivalents, including those segregated for regulatory purposes and restricted cash	(2,445)	3,760
Cash and cash equivalents, including those segregated for regulatory purposes and restricted cash at beginning of year	14,659	16,449
Cash and cash equivalents, including those segregated for regulatory purposes and restricted cash at end of period	12,214	20,209
Cash and cash equivalents, including those segregated for regulatory purposes and restricted cash
Cash and cash equivalents	8,375	5,958
Cash and cash equivalents segregated for regulatory purposes and restricted cash	3,839	14,251
Total cash and cash equivalents, including those segregated for regulatory purposes and restricted cash at end of period	12,214	20,209
Supplemental disclosures of cash flow information:
Cash paid for interest	858	137
Cash paid for income taxes, net	536	386
Cash outflows for lease liabilities	92	80
Non-cash right-of-use assets recorded for new and modified leases	112	39
Restricted stock awards issued as consideration for TriState Capital acquisition	0	28
Effective settlement of note receivable for TriState Capital acquisition	0	123
Common stock, par value $.01 per share
Supplemental disclosures of cash flow information:
Stock issued for acquisition	0	778
Preferred Stock
Supplemental disclosures of cash flow information:
Stock issued for acquisition	$ 0	$ 120