Allowance for Credit Losses - Past-Due Status (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Financing Receivable, Recorded Investment, Past Due
Loans and leases	$ 14,577,299	$ 14,312,529
Loans and Leases Past Due 90 Days or More and Still Accruing Interest	4,093	3,357
30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	40,070	44,612
60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	18,455	19,963
90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	26,521	18,751
Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	85,046	83,326
Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	14,492,253	14,229,203
Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due
Loans and leases	2,339,882	2,171,333
Loans and Leases Past Due 90 Days or More and Still Accruing Interest	249	318
Commercial and Industrial \| 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	8,313	3,009
Commercial and Industrial \| 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	1,070	7,756
Commercial and Industrial \| 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	3,393	685
Commercial and Industrial \| Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	12,776	11,450
Commercial and Industrial \| Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	2,327,106	2,159,883
Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,783,130	4,590,326
Commercial Real Estate \| 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	752	798
Commercial Real Estate \| 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	2,941	18
Commercial Real Estate \| 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	628	436
Commercial Real Estate \| Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,321	1,252
Commercial Real Estate \| Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,778,809	4,589,074
Construction
Financing Receivable, Recorded Investment, Past Due
Loans and leases	731,766	808,275
Construction \| 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	160	2,420
Construction \| 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	1,420
Construction \| 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	904	1,065
Construction \| Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	2,484	3,485
Construction \| Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	729,282	804,790
Lease financing
Financing Receivable, Recorded Investment, Past Due
Loans and leases	450,457	441,930
Lease financing \| 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases		135
Lease financing \| 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases		30
Lease financing \| 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	565	570
Lease financing \| Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	565	735
Lease financing \| Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	449,892	441,195
Residential mortgage
Financing Receivable, Recorded Investment, Past Due
Loans and leases	5,225,603
Consumer
Financing Receivable, Recorded Investment, Past Due
Loans and leases	1,046,461	1,025,838
Loans and Leases Past Due 90 Days or More and Still Accruing Interest	3,073	2,984
Consumer \| 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	12,476	13,935
Consumer \| 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	5,690	3,995
Consumer \| 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	3,073	2,984
Consumer \| Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	21,239	20,914
Consumer \| Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	1,025,222	1,004,924
Real estate loan
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,044,207	4,096,300
Real estate loan \| Residential mortgage
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,044,207	4,096,300
Loans and Leases Past Due 90 Days or More and Still Accruing Interest	771	55
Real estate loan \| Residential mortgage \| 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	14,804	18,387
Real estate loan \| Residential mortgage \| 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,890	6,522
Real estate loan \| Residential mortgage \| 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	12,119	8,133
Real estate loan \| Residential mortgage \| Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	31,813	33,042
Real estate loan \| Residential mortgage \| Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	4,012,394	4,063,258
Home Equity Line
Financing Receivable, Recorded Investment, Past Due
Loans and leases	1,181,396	1,178,527
Home Equity Line \| Home equity Line
Financing Receivable, Recorded Investment, Past Due
Loans and leases	1,181,396	1,178,527
Home Equity Line \| Home equity Line \| 30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	3,565	5,928
Home Equity Line \| Home equity Line \| 60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	2,444	1,642
Home Equity Line \| Home equity Line \| 90 Days or Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	5,839	4,878
Home Equity Line \| Home equity Line \| Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	11,848	12,448
Home Equity Line \| Home equity Line \| Not Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and leases	$ 1,169,548	$ 1,166,079