Financing Receivables - Credit Quality Information - Financial Advisor Loans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Financing receivables - credit quality information
Allowance for credit losses	$ 59	$ 59	$ 48	$ 50
Loan write-offs	1
Commercial Loans
Financing receivables - credit quality information
Allowance for credit losses	52	54	$ 45	$ 47
Loan write-offs	1
Commercial Loans | Loans to financial advisors
Financing receivables - credit quality information
Loan write-offs	0
Amortized cost basis by year of origination and loan-to-value ratio
Year 1	108	359
Year 2	346	179
Year 3	171	134
Year 4	128	101
Year 5	98	77
Prior	219	163
Total amortized cost basis	1,070	1,013
Commercial Loans | Loans to financial advisors | Active
Amortized cost basis by year of origination and loan-to-value ratio
Year 1	108	359
Year 2	346	178
Year 3	170	133
Year 4	127	99
Year 5	95	76
Prior	213	158
Total amortized cost basis	1,059	1,003
Commercial Loans | Loans to financial advisors | Terminated
Financing receivables - credit quality information
Allowance for credit losses	7	6
Amortized cost basis by year of origination and loan-to-value ratio
Year 1	0	0
Year 2	0	1
Year 3	1	1
Year 4	1	2
Year 5	3	1
Prior	6	5
Total amortized cost basis	$ 11	$ 10