Loans to Banking Clients and Related Allowance for Loan Losses (Delinquency Analysis by Loan Class) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 13,066		$ 12,407
30-59 days past due	11		6
60-89 days past due	4		6
>90 days past due and other nonaccrual loans	39		48
Total past due	54		60
Total loans	13,120	[1]	12,467	[1]
Residential real estate mortgages, first mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	7,884		7,808
30-59 days past due	5		3
60-89 days past due	3		4
>90 days past due and other nonaccrual loans	24		30
Total past due	32		37
Total loans	7,916		7,845
Residential real estate mortgages, purchased first mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	154		154
30-59 days past due	1		1
>90 days past due and other nonaccrual loans	4		6
Total past due	5		7
Total loans	159		161
Home equity lines of credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,967		3,025
30-59 days past due	3		2
60-89 days past due	1		2
>90 days past due and other nonaccrual loans	11		12
Total past due	15		16
Total loans	2,982		3,041
Personal loans secured by securities [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,031		1,384
30-59 days past due	2
Total past due	2
Total loans	2,033		1,384
Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	30		36
Total loans	$ 30		$ 36

[1] All loans are evaluated for impairment by loan segment.