Loans - Contractual Maturity of Loans Outstanding by Repricing Characteristic (Details) $ in Millions	Dec. 31, 2019 USD ($)
Receivables [Abstract]
Receivables at predetermined interest rates due after one year but within five years	$ 1,733
Receivables at floating or adjustable rates after one but within five years	29,459
Total after one but within five years	31,192
Receivables at predetermined interest rates after five years	4,929
Receivables at floating or adjustable rates after five years	12,518
Total after five years	$ 17,447