Business Acquisitions (Pro Forma Information) (Details) - USAA-IMCO [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Business Acquisition [Line Items]
Total net revenues	$ 2,474	$ 2,767	$ 5,170	$ 5,573
Net income	$ 606	$ 870	$ 1,336	$ 1,723