Loans to Banking Clients and Related Allowance for Loan Losses (Changes in Allowance for Loan Losses) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	$ 56	$ 54	$ 53
Charge-offs	(11)	(16)	(19)
Recoveries	4	2	2
Provision for loan losses	(1)	16	18
Balance at end of year	48	56	54
Residential real estate mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	36	40	38
Charge-offs	(5)	(7)	(11)
Recoveries	2	2	1
Provision for loan losses	1	1	12
Balance at end of year	34	36	40
Home equity lines of credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of year	20	14	15
Charge-offs	(6)	(9)	(8)
Recoveries	2		1
Provision for loan losses	(2)	15	6
Balance at end of year	$ 14	$ 20	$ 14