Loans Composition (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 27,817,280	$ 24,224,949
PPP
Loans and Leases Receivable Disclosure [Line Items]
Loans	1,050	66,070
Asset-based lending & equipment finance(a)
Loans and Leases Receivable Disclosure [Line Items]
Loans	380,830	178,027
Commercial and industrial
Loans and Leases Receivable Disclosure [Line Items]
Loans	9,190,045	8,208,289
Commercial real estate — owner occupied
Loans and Leases Receivable Disclosure [Line Items]
Loans	999,786	971,326
Commercial and business lending
Loans and Leases Receivable Disclosure [Line Items]
Loans	10,571,711	9,423,711
Commercial real estate — investor
Loans and Leases Receivable Disclosure [Line Items]
Loans	5,064,289	4,384,569
Real estate construction
Loans and Leases Receivable Disclosure [Line Items]
Loans	1,835,159	1,808,976
Commercial real estate lending
Loans and Leases Receivable Disclosure [Line Items]
Loans	6,899,449	6,193,545
Total commercial
Loans and Leases Receivable Disclosure [Line Items]
Loans	17,471,159	15,617,256
Residential mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	8,314,902	7,567,310
Auto finance
Loans and Leases Receivable Disclosure [Line Items]
Loans	1,117,136	143,045
Home equity
Loans and Leases Receivable Disclosure [Line Items]
Loans	612,608	595,615
Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans	301,475	301,723
Total consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 10,346,121	$ 8,607,693