Bank Loans and Related Allowance for Credit Losses (Convert to Amortizing Loans) (Details) - HELOCs [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
HELOCs converted to amortizing loans	$ 19	$ 26
Converted to an amortizing loan by period end	279
Within 1 year	16
> 1 year – 3 years	72
> 3 years – 5 years	65
> 5 years	216
Total	$ 648