Loans - Schedule of Additional Information on Nonaccrual Loans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Receivables [Abstract]
Interest income that would have been recorded if the nonaccrual receivable had been current in accordance with contractual terms during the period	$ 43	$ 35	$ 46
Interest income that was recorded on nonaccrual loans and included in interest income during the period	$ 12	$ 15	$ 31