v3.26.1
Commitments and Contingencies - Schedule of Financial Instruments with Off-Balance Sheet Risk (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Commitments to originate loans and leases:    
Unadvanced portion of loans and leases $ 2,375,707 $ 2,483,239
Unused lines of credit:    
Home equity 1,195,828 1,175,702
Other consumer 264,211 148,358
Other commercial 0 0
Unused letters of credit:    
Financial standby letters of credit 5,852 10,440
Performance standby letters of credit 42,586 25,025
Commercial and similar letters of credit 2,671 58,074
Interest rate derivatives    
Unused letters of credit:    
Notional amount 94,872 192,468
Receive fixed, pay variable    
Unused letters of credit:    
Notional amount 3,590,798 3,505,840
Pay fixed, receive variable    
Unused letters of credit:    
Notional amount 3,594,646 3,505,840
Risk participation-out agreements    
Unused letters of credit:    
Notional amount 727,509 670,834
Risk participation-in agreements    
Unused letters of credit:    
Notional amount 145,982 153,185
Foreign exchange contracts | Buys foreign currency, sells U.S. currency    
Unused letters of credit:    
Notional amount 3,583 2,785
Foreign exchange contracts | Sells foreign currency, buys U.S. currency    
Unused letters of credit:    
Notional amount 3,601 2,800
Commercial real estate    
Commitments to originate loans and leases:    
Commitments to originate loans and leases 173,872 99,457
Commercial    
Commitments to originate loans and leases:    
Commitments to originate loans and leases 209,081 137,923
Residential mortgage    
Commitments to originate loans and leases:    
Commitments to originate loans and leases 18,274 23,115
Home equity    
Commitments to originate loans and leases:    
Commitments to originate loans and leases $ 27,017 $ 9,022