Collateralized Transactions (Cash And Securities Deposited With Clearing Organizations Or Segregated Under Federal And Other Regulations Or Requirements) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Sep. 30, 2015	Dec. 31, 2014
Collateralized Transactions
Cash deposited with clearing organizations or segregated under federal and other regulations or requirements		$ 35,552	$ 40,607
Securities		16,946	14,630
Total		$ 52,498	$ 55,237
Cash Initial Margin Received from Customers and remitted to clearing organizations	$ 3,800