Bank Loans and Related Allowance for Credit Losses (Convert to Amortizing Loans) (Details) - HELOCs [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
HELOCs converted to amortizing loans	$ 7	$ 8	$ 14	$ 18
Converted to an amortizing loan by period end	323		323
Within 1 year	16		16
> 1 year – 3 years	82		82
> 3 years – 5 years	76		76
> 5 years	229		229
Total	$ 726		$ 726