Allowance for Credit Losses - Past-Due Status (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Financing Receivable, Recorded Investment, Past Due
Loans and leases	$ 14,293,036	$ 14,408,258
Loans and Leases Past Due 90 Days or More and Still Accruing Interest	4,302	6,019
30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	39,846	45,124
60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	16,923	14,138
90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	14,007	18,355
Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	70,776	77,617
Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	14,222,260	14,330,641
Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due
Loans and leases	2,261,394	2,247,428
Loans and Leases Past Due 90 Days or More and Still Accruing Interest	740	1,432
Commercial and Industrial | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	3,596	1,481
Commercial and Industrial | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	934	563
Commercial and Industrial | 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	740	1,595
Commercial and Industrial | Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	5,270	3,639
Commercial and Industrial | Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	2,256,124	2,243,789
Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,367,433	4,463,992
Commercial Real Estate | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	378
Commercial Real Estate | 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases		153
Commercial Real Estate | Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	378	153
Commercial Real Estate | Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,367,055	4,463,839
Construction
Financing Receivable, Recorded Investment, Past Due
Loans and leases	954,072	918,326
Loans and Leases Past Due 90 Days or More and Still Accruing Interest		536
Construction | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	1,193	434
Construction | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	2,295	1,179
Construction | 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases		536
Construction | Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	3,488	2,149
Construction | Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	950,584	916,177
Lease financing
Financing Receivable, Recorded Investment, Past Due
Loans and leases	437,399	434,650
Lease financing | Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	437,399	434,650
Residential mortgage
Financing Receivable, Recorded Investment, Past Due
Loans and leases	5,274,413
Consumer
Financing Receivable, Recorded Investment, Past Due
Loans and leases	998,325	1,023,969
Loans and Leases Past Due 90 Days or More and Still Accruing Interest	2,554	2,734
Consumer | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	14,883	17,591
Consumer | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	3,430	3,946
Consumer | 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	2,554	2,734
Consumer | Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	20,867	24,271
Consumer | Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	977,458	999,698
Real estate loan
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,129,518	4,168,154
Real estate loan | Residential mortgage
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,129,518	4,168,154
Loans and Leases Past Due 90 Days or More and Still Accruing Interest	1,008	1,317
Real estate loan | Residential mortgage | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	15,546	19,971
Real estate loan | Residential mortgage | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	9,461	7,478
Real estate loan | Residential mortgage | 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	7,698	9,392
Real estate loan | Residential mortgage | Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	32,705	36,841
Real estate loan | Residential mortgage | Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,096,813	4,131,313
Home Equity Line
Financing Receivable, Recorded Investment, Past Due
Loans and leases	1,144,895	1,151,739
Home Equity Line | Home equity Line
Financing Receivable, Recorded Investment, Past Due
Loans and leases	1,144,895	1,151,739
Home Equity Line | Home equity Line | 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,250	5,647
Home Equity Line | Home equity Line | 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	803	972
Home Equity Line | Home equity Line | 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	3,015	3,945
Home Equity Line | Home equity Line | Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	8,068	10,564
Home Equity Line | Home equity Line | Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	$ 1,136,827	$ 1,141,175