Cash, Loan and Dividend Restrictions (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 01, 2019	Jul. 23, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Cash, Loan and Dividend Restrictions [Line Items]
Average Cash Reserve Deposit Required And Made Federal Reserve Banks					$ 11,179		$ 12,428
Common Stock, Dividends, Per Share, Declared			$ 0.450	$ 0.390	$ 0.900	$ 0.780
Reserve Balance for Non-US Central Banks [Member]
Cash, Loan and Dividend Restrictions [Line Items]
Restricted Cash Equivalents			$ 556		$ 556		517
Segregated for benefit brokerage customers under federal and other brokerage regulations [Member]
Cash, Loan and Dividend Restrictions [Line Items]
Restricted Cash Equivalents			956		956		1,135
Related to consolidated variable interest entities (VIEs) that can only be used to settle liabilities of VIEs [Member]
Cash, Loan and Dividend Restrictions [Line Items]
Restricted Cash Equivalents			19		19		$ 147
Bank Subsidiaries [Member]
Cash, Loan and Dividend Restrictions [Line Items]
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments without Regulatory Approval			7,600		7,600
Nonbank Subsidiaries [Member]
Cash, Loan and Dividend Restrictions [Line Items]
Statutory Accounting Practices, Statutory Amount Available for Dividend Payments without Regulatory Approval			$ 25,100		$ 25,100
Subsequent Event [Member]
Cash, Loan and Dividend Restrictions [Line Items]
Common Stock, Dividends, Per Share, Declared		$ 0.51
Dividends Payable, Date Declared		Jul. 23, 2019
Dividends Payable, Date to be Paid	Sep. 01, 2019