Regulatory Requirements - Net Capital and Net Capital Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
CS&Co
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Net capital	$ 5,629,000	$ 5,386,000
Minimum dollar requirement	250	250
2% of aggregate debit balances	1,069,000	778,000
Net capital in excess of required net capital	4,560,000	4,608,000
TDAC
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Net capital	3,634,000	5,291,000
Minimum dollar requirement	1,500	1,500
2% of aggregate debit balances	440,000	626,000
Net capital in excess of required net capital	3,194,000	4,665,000
TD Ameritrade, Inc.
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Net capital	444,000	806,000
Minimum dollar requirement	250	250
2% of aggregate debit balances	0	0
Net capital in excess of required net capital	$ 444,000	$ 806,000