Loan Receivables (Schedule of Loans That Entered a Modification Program During the Period) (Details) $ in Millions		3 Months Ended
		Mar. 31, 2020 USD ($) accounts	Mar. 31, 2019 USD ($) accounts
Credit Card Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts that entered a TDR program during the period, number of accounts (in accounts) | accounts	[1]	92,736	92,356
Accounts that entered a TDR program during the period, balances	[1]	$ 609	$ 592
Accounts that entered a TDR program during the period and were converted from revolving line-of-credit arrangements to term loans, balances		$ 210	$ 163
Total Other Loans [Member] | Private Student Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts that entered a TDR program during the period, number of accounts (in accounts) | accounts		1,718	1,576
Accounts that entered a TDR program during the period, balances		$ 32	$ 31
Total Other Loans [Member] | Personal Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts that entered a TDR program during the period, number of accounts (in accounts) | accounts		2,548	2,600
Accounts that entered a TDR program during the period, balances		$ 34	$ 35

[1] Accounts that entered a credit card TDR program include $210 million and $163 million that were converted from revolving line-of-credit arrangements to term loans during the three months ended March 31, 2020 and 2019, respectively.