Loans Composition (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 29,848,904	$ 28,799,569
Commercial and industrial
Loans and Leases Receivable Disclosure [Line Items]
Loans	10,055,487	9,759,454
Commercial real estate — owner occupied
Loans and Leases Receivable Disclosure [Line Items]
Loans	1,058,237	991,722
Commercial and business lending
Loans and Leases Receivable Disclosure [Line Items]
Loans	11,113,724	10,751,176
Commercial real estate — investor
Loans and Leases Receivable Disclosure [Line Items]
Loans	5,312,928	5,080,344
Real estate construction
Loans and Leases Receivable Disclosure [Line Items]
Loans	2,009,060	2,155,222
Commercial real estate lending
Loans and Leases Receivable Disclosure [Line Items]
Loans	7,321,988	7,235,565
Total commercial
Loans and Leases Receivable Disclosure [Line Items]
Loans	18,435,711	17,986,742
Residential mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	8,746,345	8,511,550
Auto finance
Loans and Leases Receivable Disclosure [Line Items]
Loans	1,777,974	1,382,073
Home equity
Loans and Leases Receivable Disclosure [Line Items]
Loans	615,506	624,353
Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans	273,367	294,851
Total consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 11,413,193	$ 10,812,828