Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017
Cash Flows from Operating Activities
Net income		$ 2,572	$ 1,757	[1]
Adjustments to reconcile net income to net cash provided by (used for) operating activities:
Share-based compensation		113	111	[1]
Depreciation and amortization		226	200	[1]
Premium amortization, net, on available for sale and held to maturity securities		276	240	[1]
Other		108	35	[1]
Net change in:
Investments segregated and on deposit for regulatory purposes		6,973	6,864	[1]
Receivables from brokers, dealers, and clearing organizations		(147)	61	[1]
Receivables from brokerage clients		(1,858)	(1,310)	[1]
Other securities owned		39	22	[1]
Other assets		(143)	(76)	[1]
Payables to brokers, dealers, and clearing organizations		43	(957)	[1]
Payables to brokerage clients		(3,392)	(4,414)	[1]
Accrued expenses and other liabilities		(155)	(82)	[1]
Net cash provided by operating activities		4,655	2,451	[1]
Cash Flows from Investing Activities
Purchases of available for sale securities		(19,781)	(6,375)	[1]
Proceeds from sales of available for sale securities		115	5,773	[1]
Principal payments on available for sale securities		12,091	6,532	[1]
Purchases of held to maturity securities		(30,639)	(19,886)	[1]
Principal payments on held to maturity securities		12,382	7,927	[1]
Net increase in bank loans		(86)	(829)	[1]
Purchases of equipment, office facilities, and property		(400)	(267)	[1]
Purchases of Federal Home Loan Bank stock		(156)	(160)	[1]
Proceeds from sales of Federal Home Loan Bank stock		528	106	[1]
Other investing activities		(74)	(52)	[1]
Net cash provided by (used for) investing activities		(26,020)	(7,231)	[1]
Cash Flows from Financing Activities
Net change in bank deposits		43,752	1,809	[1]
Net change in short-term borrowings		(15,000)	5,000	[1]
Issuance of long-term debt		1,936	643	[1]
Repayment of long-term debt		(906)	(256)	[1]
Dividends paid		(579)	(456)	[1]
Proceeds from stock options exercised and other		108	98	[1]
Other financing activities		(12)	(10)	[1]
Net cash provided by (used for) financing activities		29,299	6,828	[1]
Increase (Decrease) in Cash and Cash Equivalents, including Amounts Restricted		7,934	2,048	[1]
Cash and Cash Equivalents including Amounts Restricted at Beginning of Year		19,160	17,873	[1]
Cash and Cash Equivalents, including Amounts Restricted at End of Period	[2]	27,094	19,921	[1]
Cash paid during the period for:
Interest		550	233
Income taxes		649	890
Non-cash investing activity:
Securities purchased during the period but settled after period end		$ 221	$ 3,977

[1] Adjusted for the retrospective adoption of ASU 2016-18. See Note 2.

[2] Reconciliation of cash, cash equivalents and amounts reported within the balance sheet