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Significant Accounting Policies (Schedule Of Securities Segregated For Regulatory Purposes) (Details) - USD ($) $ in Millions		Mar. 31, 2022	Dec. 31, 2021
Marketable Securities [Line Items]
Securities - segregated for regulatory purposes		$ 24,350	$ 15,121
US Government Securities [Member]
Marketable Securities [Line Items]
Securities - segregated for regulatory purposes		7,416	4,729
Securities Purchased Under Agreement To Resell [Member]
Marketable Securities [Line Items]
Securities - segregated for regulatory purposes	[1]	$ 16,934	$ 10,392
[1] These balances are collateralized by U.S. government securities.

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- Definition

Securities deposited in a special reserve account for the exclusive benefit of customers pursuant to SEC Regulations.

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