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Loans and Leases (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Dec. 31, 2025
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans pledged to secure borrowings	$ 6,100		$ 6,100		$ 6,500
Loans and leases, deferred fees and costs	53		53		54
Discounts on acquired loans	578		578		707
Principal Balance of Loan	46,915		46,915		47,776
Carrying balance of PCD loans	46,453		46,453		47,310
Interest income recognized on leases	6	$ 6	17	$ 17
Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Principal Balance of Loan	26,497		26,497		27,870
Commercial real estate \| Non-owner occupied term
Financing Receivable, Allowance for Credit Loss [Line Items]
Principal Balance of Loan	7,338		7,338		8,206
Columbia Banking Systems and Pacific Premier Bancorp Merger \| Commercial real estate \| Non-owner occupied term
Financing Receivable, Allowance for Credit Loss [Line Items]
Principal Balance of Loan					177
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Loss [Line Items]
Principal Balance of Loan	381		381		473
Carrying balance of PCD loans	345		345		416
Asset Pledged as Collateral
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans pledged to secure borrowings	$ 29,600		$ 29,600		30,600
Minimum
Financing Receivable, Allowance for Credit Loss [Line Items]
Lease term	3 years		3 years
Maximum
Financing Receivable, Allowance for Credit Loss [Line Items]
Lease term	5 years		5 years
Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Interest Receivable	$ 183		$ 183		$ 186