Loans to Banking Clients and Related Allowance for Loan Losses (Delinquency Analysis by Loan Class) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 12,583	$ 12,407
30-59 days past due	13	6
60-89 days past due	3	6
>90 days past due and other nonaccrual loans	40	48
Total past due	56	60
Total loans	12,639	12,467
Residential real estate mortgages, first mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	7,856	7,808
30-59 days past due	6	3
60-89 days past due	2	4
>90 days past due and other nonaccrual loans	25	30
Total past due	33	37
Total loans	7,889	7,845
Residential real estate mortgages, purchased first mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	155	154
30-59 days past due	1	1
>90 days past due and other nonaccrual loans	5	6
Total past due	6	7
Total loans	161	161
Home equity lines of credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	3,004	3,025
30-59 days past due	3	2
60-89 days past due	1	2
>90 days past due and other nonaccrual loans	10	12
Total past due	14	16
Total loans	3,018	3,041
Personal loans secured by securities [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,533	1,384
30-59 days past due	3
Total past due	3
Total loans	1,536	1,384
Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	35	36
Total loans	$ 35	$ 36