Fair Value Disclosures - Financial Assets and Liabilities Not Recorded at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Financial assets:
Loans and leases HFI, net of ALLL	$ 285,078	$ 293,899
HTM securities	1,495	0
Financial liabilities:
Time deposits	15,886	21,941
Long-term debt	35,913	39,597
Carrying Amount
Financial assets:
Loans and leases HFI, net of ALLL	285,055	293,899
HTM securities	1,494	0
Financial liabilities:
Time deposits	15,886	21,941
Long-term debt	35,913	39,597
Fair Value | Level 2
Financial assets:
HTM securities	1,495	0
Financial liabilities:
Time deposits	16,017	22,095
Long-term debt	36,251	40,864
Fair Value | Level 3
Financial assets:
Loans and leases HFI, net of ALLL	$ 284,914	$ 295,461