Loans - Narrative, Loans Held-for-Investment (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-sale	$ 950	$ 0
PCI loans	$ 4,229,974	$ 4,243,693
Home equity loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of PCI loans	10.00%	10.00%
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of PCI loans	27.00%	28.00%
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of PCI loans	55.00%	53.00%
One-to-four family residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of PCI loans	8.00%	9.00%
PCD loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
PCI loans	$ 10,371	$ 11,502