Deposits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Deposits By Type [Abstract]
Brokerage sweep deposits	$ 27,949	$ 39,322
Bank sweep deposits(1)	6,355	0
Savings deposits(2)	2,592	4,133
Other deposits(3)	1,710	1,858
Total deposits	38,606	45,313
Deposits Textuals [Abstract]
Premium Savings Account deposits	1,000	2,000
Non-interest-bearing deposits	197	$ 193
Reciprocal deposits received from third party Bank	$ 1,000