Loans Composition (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 24,531,926	$ 24,224,949
Interest receivable	83,120	80,528
Loans and Finance Receivables [Member]
Loans and Leases Receivable Disclosure [Line Items]
Interest receivable	58,000	55,000
PPP
Loans and Leases Receivable Disclosure [Line Items]
Loans	17,995	66,070
Asset-Based Lending
Loans and Leases Receivable Disclosure [Line Items]
Loans	231,040	178,027
Commercial and industrial
Loans and Leases Receivable Disclosure [Line Items]
Loans	8,102,380	8,208,289
Commercial real estate — owner occupied
Loans and Leases Receivable Disclosure [Line Items]
Loans	973,572	971,326
Commercial and business lending
Loans and Leases Receivable Disclosure [Line Items]
Loans	9,324,986	9,423,711
Commercial real estate — investor
Loans and Leases Receivable Disclosure [Line Items]
Loans	4,469,241	4,384,569
Real estate construction
Loans and Leases Receivable Disclosure [Line Items]
Loans	1,760,076	1,808,976
Commercial real estate lending
Loans and Leases Receivable Disclosure [Line Items]
Loans	6,229,317	6,193,545
Total commercial
Loans and Leases Receivable Disclosure [Line Items]
Loans	15,554,303	15,617,256
Residential mortgage
Loans and Leases Receivable Disclosure [Line Items]
Loans	7,609,343	7,567,310
Home equity
Loans and Leases Receivable Disclosure [Line Items]
Loans	580,867	595,615
Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans	289,889	301,723
Auto
Loans and Leases Receivable Disclosure [Line Items]
Loans	497,523	143,045
Total consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 8,977,622	$ 8,607,693