Loan Receivables (Schedule of Troubled Debt Restructurings That Subsequently Defaulted) (Details) $ in Millions		3 Months Ended
		Mar. 31, 2020 USD ($) missed_payments accounts	Mar. 31, 2019 USD ($) accounts
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amount of missed payments after which a customer defaults from a TDR program (in payments) | missed_payments		2
Credit Card Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs that subsequently defaulted, number of accounts (in accounts) | accounts	[1],[2]	20,485	15,652
TDRs that subsequently defaulted, aggregated outstanding balances upon default | $	[1],[2]	$ 117	$ 90
Total Other Loans [Member] | Private Student Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs that subsequently defaulted, number of accounts (in accounts) | accounts	[3]	358	280
TDRs that subsequently defaulted, aggregated outstanding balances upon default | $	[3]	$ 7	$ 5
Delinquency days to default (in days)		60 days
Total Other Loans [Member] | Personal Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs that subsequently defaulted, number of accounts (in accounts) | accounts	[2]	1,200	848
TDRs that subsequently defaulted, aggregated outstanding balances upon default | $	[2]	$ 18	$ 13

[1] Terms revert back to the pre-modification terms for customers who default from a temporary program and charging privileges remain suspended in most cases.

[2] For credit card loans and personal loans, a customer defaults from a TDR program after two consecutive missed payments. The outstanding balance upon default is generally the loan balance at the end of the month prior to default.

[3] For student loans, defaults have been defined as loans that are 60 or more days delinquent. The outstanding balance upon default is generally the loan balance at the end of the month prior to default.