Acquisition and Divestiture - Summary of Unpaid Principal Balance to Fair Value of Loans and Leases by Portfolio Segment (Details) - USD ($) $ in Thousands		Apr. 01, 2022	Sep. 30, 2023	Jun. 30, 2023	Jan. 01, 2023	Sep. 30, 2022	Jun. 30, 2022	Jan. 01, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance			$ 2,341,938			$ 2,429,326
Allowance for credit losses at acquisition				$ (2,435,581)	$ (2,438,435)		$ (2,633,005)	$ (2,060,083)
PCD Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	[1]	$ 3,410,506
Allowance for credit losses at acquisition	[1]	(99,000)
Other discount		(106,814)
Fair value		3,204,692
Non PCD Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance		32,896,454
Other discount	[2]	(260,498)
Fair value		$ 32,635,956

[1] The unpaid principal balance and allowance for credit losses at acquisition is net of charge-offs of $33 million recognized on the PCD loans

[2] Includes approximately $242 million of principal balances not expected to be collected.