Financing Receivables - Credit Quality Information - Financial Advisor Loans (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Financing receivables - credit quality information
Allowance for credit losses	$ 57	$ 50	$ 51	$ 68
Commercial Loans
Financing receivables - credit quality information
Allowance for credit losses	53	47	$ 48	$ 66
Commercial Loans | Loans to financial advisors
Amortized cost basis by year of origination and loan-to-value ratio
Year 1	162	137
Year 2	121	148
Year 3	129	119
Year 4	106	89
Year 5	80	116
Prior	182	119
Total amortized cost basis	780	728
Commercial Loans | Loans to financial advisors | Active
Amortized cost basis by year of origination and loan-to-value ratio
Year 1	162	136
Year 2	120	147
Year 3	128	119
Year 4	104	89
Year 5	79	116
Prior	176	113
Total amortized cost basis	769	720
Commercial Loans | Loans to financial advisors | Terminated
Financing receivables - credit quality information
Allowance for credit losses	6	5
Amortized cost basis by year of origination and loan-to-value ratio
Year 1	0	1
Year 2	1	1
Year 3	1	0
Year 4	2	0
Year 5	1	0
Prior	6	6
Total amortized cost basis	$ 11	$ 8