Loans Composition (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 29,207,072	$ 28,799,569
Asset-based lending & equipment finance
Loans and Leases Receivable Disclosure [Line Items]
Loans	522,834	458,887
Commercial and industrial
Loans and Leases Receivable Disclosure [Line Items]
Loans	9,346,947	9,300,567
Commercial real estate — owner occupied
Loans and Leases Receivable Disclosure [Line Items]
Loans	1,050,236	991,722
Commercial and business lending
Loans and Leases Receivable Disclosure [Line Items]
Loans	10,920,017	10,751,176
Commercial real estate — investor
Loans and Leases Receivable Disclosure [Line Items]
Loans	5,094,249	5,080,344
Real estate construction
Loans and Leases Receivable Disclosure [Line Items]
Loans	2,147,070	2,155,222
Commercial real estate lending
Loans and Leases Receivable Disclosure [Line Items]
Loans	7,241,318	7,235,565
Total commercial
Loans and Leases Receivable Disclosure [Line Items]
Loans	18,161,335	17,986,742
Residential mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	8,605,164	8,511,550
Auto finance
Loans and Leases Receivable Disclosure [Line Items]
Loans	1,551,538	1,382,073
Home equity
Loans and Leases Receivable Disclosure [Line Items]
Loans	609,787	624,353
Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans	279,248	294,851
Total consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 11,045,737	$ 10,812,828